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High-Resolution Inkjet Printing of All-Polymer Transistor Circuits | [
{
"abstract": "Direct printing of functional electronic materials may provide a new route to low cost fabrication of integrated circuits. However, to be useful it must allow continuous manufacturing of all circuit components by successive solution deposition and printing steps in the same environment. We demonstrate direct inkjet printing of complete transistor circuits, including via hole interconnections based on solution processed polymer conductors, insulators, and self organizing semiconductors. We show that the use of substrate surface energy patterning to direct the flow of water based conducting polymer inkjet droplets enables high resolution definition of practical channel lengths of 5 micrometers. High mobilities of 0.02 square centimeters per volt second and on off current switching ratios of 10(5) were achieved.",
"author_names": [
"Henning Sirringhaus",
"Takeo Kawase",
"Richard H Friend",
"Tatsuya Shimoda",
"Muthiah N Inbasekaran",
"W Wu",
"Edmund P Woo"
],
"corpus_id": 4491859,
"doc_id": "4491859",
"n_citations": 2466,
"n_key_citations": 18,
"score": 1,
"title": "High resolution inkjet printing of all polymer transistor circuits.",
"venue": "Science",
"year": 2000
},
{
"abstract": "www.sciencemag.org (this information is current as of April 13, 2009 The following resources related to this article are available online at http:/www.sciencemag.org/cgi/content/full/290/5499/2123 version of this article at: including high resolution figures, can be found in the online Updated information and services, http:/www.sciencemag.org/cgi/content/full/290/5499/2123#otherarticles 4 of which can be accessed for free: cites 19 articles This article 689 article(s) on the ISI Web of Science. cited by This article has been http:/www.sciencemag.org/cgi/content/full/290/5499/2123#otherarticles 13 articles hosted by HighWire Press; see: cited by This article has been http:/www.sciencemag.org/cgi/collection/mat_sci Materials Science subject collections This article appears in the following http:/www.sciencemag.org/about/permissions.dtl in whole or in part can be found at: this article permission to reproduce of this article or about obtaining reprints Information about obtaining",
"author_names": [
"Jorg Schotter",
"G A Kastle",
"N C Emley",
"Takasada Shibauchi",
"Lia Krusin-Elbaum",
"Kathryn W Guarini",
"C T Black",
"Mark T Tuominen"
],
"corpus_id": 16709226,
"doc_id": "16709226",
"n_citations": 396,
"n_key_citations": 8,
"score": 0,
"title": "High Resolution Inkjet Printing of All Polymer Transistor Circuits",
"venue": "",
"year": 2009
},
{
"abstract": "All polymer TFTs are developed using an inkjet printing process. Conductive polymer is deposited onto a substrate having a wettability contrast to realize a channel length of 10/spl mu/m and 500/spl mu/m width. Polymer integrated circuits and active matrix backplanes are also developed and their operation demonstrated.",
"author_names": [
"Tatsuya Shimoda",
"Takeo Kawase"
],
"corpus_id": 42840635,
"doc_id": "42840635",
"n_citations": 6,
"n_key_citations": 0,
"score": 0,
"title": "All polymer thin film transistor fabricated by high resolution ink jet printing",
"venue": "2004 IEEE International Solid State Circuits Conference (IEEE Cat. No.04CH37519)",
"year": 2004
},
{
"abstract": "Impressive advances in vapor phase deposition and photolithographic patterning techniques have been fueling the silicon microelectronics revolution over the last 40 years. However, for many interesting classes of materials, including biological materials or functional synthetic polymers, vacuum deposition and photolithography are not the techniques of choice for producing ordered structures and devices. Many of these materials selfassemble into well ordered microstructures when deposited from solution, and patterning may be more readily achieved by solution based selective deposition and direct printing techniques. It is appealing to consider novel ways of manufacturing functional circuits and devices based on techniques that are similar to printing visual information onto paper.",
"author_names": [
"Henning Sirringhaus",
"Takeo Kawase",
"Richard H Friend"
],
"corpus_id": 138114541,
"doc_id": "138114541",
"n_citations": 88,
"n_key_citations": 0,
"score": 0,
"title": "High Resolution Ink Jet Printing of All Polymer Transistor Circuits",
"venue": "",
"year": 2001
},
{
"abstract": "Inkjet printing on pre fabricated high resolution substrate is developed to improve the operational speed of printed organic transistors. The high resolution features are designed to define transistor critical dimensions, while maintaining the flexibility to incorporate different circuit constructions. Logic gate and ring oscillator circuits fabricated by inkjet printing on the high resolution substrate are demonstrated, to show that the same high resolution pattern can be adapted for constructing different electronic circuits.",
"author_names": [
"Ping Mei",
"Tse Nga Ng",
"Rene A Lujan",
"David E Schwartz",
"Sivkheng Kor",
"Brent Krusor",
"Janos Veres"
],
"corpus_id": 108722873,
"doc_id": "108722873",
"n_citations": 19,
"n_key_citations": 0,
"score": 0,
"title": "Utilizing high resolution and reconfigurable patterns in combination with inkjet printing to produce high performance circuits",
"venue": "",
"year": 2014
},
{
"abstract": "As demands for high pixel densities and wearable forms of displays increase, high resolution printing technologies to achieve high performance transistors beyond current amorphous silicon levels and to allow low temperature solution processability for plastic substrates have been explored as key processes in emerging flexible electronics. This study describes electrohydrodynamic inkjet (e jet) technology for direct printing of oxide semiconductor thin film transistors (TFTs) with high resolution (minimum line width: 2 mm) and superb performance, including high mobility ~230 cm2 V 1 s 1) Logic operations of the amplifier circuits composed of these e jet printed metal oxide semiconductor (MOS) TFTs demonstrate their high performance. Printed In2O TFTs with e jet printing assisted high resolution S/D electrodes were prepared, and the direct printing of passivation layers on these channels enhanced their gate bias stabilities significantly. Moreover, low process temperatures <250 degC) enable the use of thin plastic substrates; highly flexible and stretchable TFT arrays have been demonstrated, suggesting promise for next generation printed electronics.",
"author_names": [
"S Y Kim",
"K Kim",
"Young Hwan Hwang",
"J Park",
"J Jang",
"Yonghyun Nam",
"Y Kang",
"M Kim",
"H Park",
"Zonghoon Lee",
"J Choi",
"Yumee Kim",
"S Jeong",
"Byeong-Soo Bae",
"J-U Park"
],
"corpus_id": 38859061,
"doc_id": "38859061",
"n_citations": 57,
"n_key_citations": 0,
"score": 0,
"title": "High resolution electrohydrodynamic inkjet printing of stretchable metal oxide semiconductor transistors with high performance.",
"venue": "Nanoscale",
"year": 2016
},
{
"abstract": "Abstract It is a big challenge to construct large scale, high resolution and high performance inkjet printed metal oxide thin film transistor (TFT) arrays with independent gates for the new printed displays. Here, a self confined inkjet printing technology has been developed to construct large area (64 x 64 array) high resolution and high performance metal oxide bilayer (In2O3/IGZO) heterojunction TFTs with independent bottom gates on transparent glass substrates. Inkjet printing In2O3 dot arrays with the diameters from 55 to 70 mm and the thickness of ~10 nm were firstly deposited on UV/ozone treated AlOx dielectric layers, and then IGZO dots were selectively printed on the top of In2O3 dots by self confined technology to form In2O3/IGZO heterojunction channels. When the inkjet printed IO layers treated by UV/ozone for more than 30 min or oxygen plasma for 5 min prior to print IGZO thin films, the mobility of the resulting printed In2O3/IGZO heterojunction TFTs are correspondingly enhanced to be 18.80 and 28.44 cm2 V 1 s 1 with excellent on/off ratios >108) and negligible hysteresis. Furthermore, the printed N Metal Oxide Semiconductor (NMOS) inverter consisted of an In2O3/IGZO TFT and an IGZO TFT has been demonstrated, which show excellent performance with the voltage gain up to 112. The strategy demonstrated here can be considered as general approaches to realize a new generation of high performance printed logic gates, circuits and display driving circuits.",
"author_names": [
"Shuangshuang Shao",
"Kun Liang",
"Xinxin Li",
"Jinfeng Zhang",
"Chuan Liu",
"Zheng Cui",
"Jianwen Zhao"
],
"corpus_id": 233587163,
"doc_id": "233587163",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Large area (64 x 64 array) inkjet printed high performance metal oxide bilayer heterojunction thin film transistors and n metal oxide semiconductor (NMOS) inverters",
"venue": "",
"year": 2021
},
{
"abstract": "Conjugated polymer semiconductors deposited from solution are best known for their electroluminescent properties and use in light emitting diode devices. However, they have recently also become of interest for applications in thin film transistors. By making use of self organisation mechanisms such as phase separation or liquid crystallinity ordered thin films can be deposited from solution in which high charge carrier mobilties on the order l0 2 10 1 cmtlvs can be achieved. In conffast to inorganic semiconductor transistors which are fabricated by complex vacuum deposition and photolithography, polymer semiconductors may enable low cost fabrication of functional transistor circuits by a combination of solution processing and direct printing.",
"author_names": [
"Henning Sirringhaus",
"Takeo Kawasel",
"Tatsuya Shimodal",
"",
"Richard H Friend"
],
"corpus_id": 213176866,
"doc_id": "213176866",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "F 6 1 Invited All Polymer Thin Film Transistors Fabricated by High Resolution Ink jet Printing",
"venue": "",
"year": 2008
},
{
"abstract": "All polymer thin film transistors (TFTs) are fabricated by ink jet printing for the first time. Source/drain electrodes are printed using a conducting polymer (PEDOT) solution on substrates with patterned wetting and dewetting regions. A channel length down to 5 /spl mu/m has been achieved without short circuits. The TFTs show a high mobility of 0.02 cm/sup 2//V/spl middot/s and on/off ratio of more than 10/sup 5/ These characteristics are equal or better than reference devices with gold electrodes. The fabrication of printed inverters is also demonstated, in which components such as gate electrodes, interconnections, via holes or resistors, are patterned with the ink jet technique.",
"author_names": [
"Takeo Kawase",
"Henning Sirringhaus",
"Richard H Friend",
"Tatsuya Shimoda"
],
"corpus_id": 114529661,
"doc_id": "114529661",
"n_citations": 27,
"n_key_citations": 0,
"score": 0,
"title": "All polymer thin film transistors fabricated by high resolution ink jet printing",
"venue": "International Electron Devices Meeting 2000. Technical Digest. IEDM (Cat. No.00CH37138)",
"year": 2000
},
{
"abstract": "All polymer thin film transistors and circuits have been fabricated by inkjet printing. Source, drain and gate electrodes were printed with a solution of conducting conjugated polymer, poly ethylenedioxythiophene (PEDOT) and semiconductor and gate dielectric were spin coated from solutions of conjugated polymer and insulator polymer, respectively. The transistors printed in air show comparable performances to the reference samples with gold electrodes. In order to overcome the resolution limit of inkjet printing, water based PEDOT solution has been deposited onto a pre patterned substrate which defines a channel by wettability contrast between hydrophilic and hydrophobic surface regions. Polymer transistors with a channel length of 5 microns have been achieved by this approach. In order to improve carrier mobility, main chains of the polymer semiconductor were self aligned along the channel direction, and a mobility of 0.02 cm2/V+s has been achieved in the printed transistor. We demonstrate simple printed circuits (inverters) with via holes and load resistors formed by inkjet technology.",
"author_names": [
"Takeo Kawase",
"Henning Sirringhaus",
"Richard H Friend",
"Tatsuya Shimoda"
],
"corpus_id": 111010582,
"doc_id": "111010582",
"n_citations": 8,
"n_key_citations": 0,
"score": 0,
"title": "All polymer thin film transistors fabricated by inkjet printing",
"venue": "SPIE Optics Photonics",
"year": 2001
}
] |
organic solar cell .ETL | [
{
"abstract": "Summary Recently, non fullerene n type organic semiconductors have attracted significant attention as acceptors in organic photovoltaics (OPVs) due to their great potential to realize high power conversion efficiencies. The rational design of the central fused ring unit of these acceptor molecules is crucial to maximize device performance. Here, we report a new class of non fullerene acceptor, Y6, that employs a ladder type electron deficient core based central fused ring (dithienothiophen[3.2 b] pyrrolobenzothiadiazole) with a benzothiadiazole (BT) core to fine tune its absorption and electron affinity. OPVs made from Y6 in conventional and inverted architectures each exhibited a high efficiency of 15.7% measured in two separate labs. Inverted device structures were certified at Enli Tech Laboratory demonstrated an efficiency of 14.9% We further observed that the Y6 based devices maintain a high efficiency of 13.6% with an active layer thickness of 300 nm. The electron deficient core based fused ring reported in this work opens a new door in the molecular design of high performance acceptors for OPVs.",
"author_names": [
"Jun Yuan",
"Yunqiang Zhang",
"Liuyang Zhou",
"Guichuan Zhang",
"Hin-Lap Yip",
"Tsz-Ki Lau",
"Xinhui Lu",
"Can Zhu",
"Hongjian Peng",
"Paul A Johnson",
"Mario Leclerc",
"Yong Cao",
"Jacek Ulanski",
"Yongfang Li",
"Yingping Zou"
],
"corpus_id": 139354200,
"doc_id": "139354200",
"n_citations": 1788,
"n_key_citations": 1,
"score": 0,
"title": "Single Junction Organic Solar Cell with over 15% Efficiency Using Fused Ring Acceptor with Electron Deficient Core",
"venue": "Joule",
"year": 2019
},
{
"abstract": "",
"author_names": [
"Qishi Liu",
"Yufan Jiang",
"Ke Jin",
"Jianqiang Qin",
"Jingui Xu",
"Wenting Li",
"Ji Xiong",
"Jinfeng Liu",
"Zuo Xiao",
"Kuan Sun",
"Shangfeng Yang",
"Xiaotao Zhang",
"Liming Ding"
],
"corpus_id": 213251511,
"doc_id": "213251511",
"n_citations": 978,
"n_key_citations": 0,
"score": 1,
"title": "18% Efficiency organic solar cells",
"venue": "",
"year": 2020
},
{
"abstract": "Besides broadening of the absorption spectrum, modulating molecular energy levels, and other well studied properties, a stronger intramolecular electron push pull effect also affords other advantages in nonfullerene acceptors. A strong push pull effect improves the dipole moment of the wings in IT 4F over IT M and results in a lower miscibility than IT M when blended with PBDB TF. This feature leads to higher domain purity in the PBDB TF:IT 4F blend and makes a contribution to the better photovoltaic performance. Moreover, the strong push pull effect also decreases the vibrational relaxation, which makes IT 4F more promising than IT M in reducing the energetic loss of organic solar cells. Above all, a power conversion efficiency of 13.7% is recorded in PBDB TF:IT 4F based devices.",
"author_names": [
"Wanning Li",
"Long Ye",
"Sunsun Li",
"Huifeng Yao",
"Harald W Ade",
"Jianhui Hou"
],
"corpus_id": 3847310,
"doc_id": "3847310",
"n_citations": 260,
"n_key_citations": 1,
"score": 0,
"title": "A High Efficiency Organic Solar Cell Enabled by the Strong Intramolecular Electron Push Pull Effect of the Nonfullerene Acceptor.",
"venue": "Advanced materials",
"year": 2018
},
{
"abstract": "With rapid development for tens of years, organic solar cells (OSCs) have attracted much attention for their potential in practical applications. As an important photovoltaic parameter, the fill factor (FF) of OSCs stands for the effectiveness of charge generation and collection, which significantly depends on the properties of the interlayer and active layer. Here, a facile and effective strategy to improve the FF through hole transporting layer (HTL) modification is demonstrated. By mixing WOx nanoparticles with a poly(3,4 ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) emulsion, the surface free energy of the HTL is improved and the morphology of the active layer is optimized. Benefiting from increased carrier lifetime, a device based on WOx :PEDOT:PSS HTL exhibits a boosted performance with an FF of 80.79% and power conversion efficiency of 14.57% PCE. The results are certified by the National Institute of Metrology (NIM) which, to date, are the highest values in this field with certification. This work offers a simple and viable option of HTL modification to realize highly efficient OSCs.",
"author_names": [
"Zhong Zheng",
"Qin Hu",
"Shaoqing Zhang",
"Dongyang Zhang",
"Jianqiu Wang",
"Shenkun Xie",
"Rong Wang",
"Yunpeng Qin",
"Wanning Li",
"Ling Hong",
"Ningning Liang",
"Feng Liu",
"Yuan Zhang",
"Zhixiang Wei",
"Zhiyong Tang",
"Thomas P Russell",
"Jianhui Hou",
"Huiqiong Zhou"
],
"corpus_id": 51606801,
"doc_id": "51606801",
"n_citations": 261,
"n_key_citations": 2,
"score": 0,
"title": "A Highly Efficient Non Fullerene Organic Solar Cell with a Fill Factor over 0.80 Enabled by a Fine Tuned Hole Transporting Layer.",
"venue": "Advanced materials",
"year": 2018
},
{
"abstract": "Nowadays, organic solar cells (OSCs) with Y6 and its derivatives as electron acceptors provide the highest efficiencies among the studied binary OSCs. To further improve the performances of OSCs, the fabrication of ternary OSCs (TOSCs) is a convenient strategy. Essentially, morphology control and the trade off between voltage and photocurrent are the main critical issues in TOSCs. Herein, we address these problems by constructing TOSCs where an alloy like composite is formed between Y6 and a newly designed derivative, BTP M. Employing an electron pushing methyl substituent as a replacement for the electron withdrawing F atoms on Y6, BTP M shows higher energy levels and lower crystallinity than Y6. As a result, the obtained Y6:BTP M alloy can simultaneously optimize energy levels to reduce energy loss as well as the morphologies of the active layers to favor photocurrent generation, leading to an enhanced open circuit voltage (Voc) of 0.875 V together with a larger short circuit current density (Jsc) of 26.56 mA cm 2 for TOSCs based on the polymer donor PM6 and Y6:BTP M acceptor alloy. Consequently, a best efficiency of 17.03% is achieved for the corresponding TOSCs, which is among the best values for single junction OSCs. In addition, our TOSCs also exhibit good thickness tolerance, and can reach 14.23% efficiency even though the active layer is as thick as 300 nm.",
"author_names": [
"Lingling Zhan",
"Shuixing Li",
"Tsz-Ki Lau",
"Yong Cui",
"Xinhui Lu",
"Minmin Shi",
"Changzhi Li",
"Hanying Li",
"Jianhui Hou",
"Hongzheng Chen"
],
"corpus_id": 213610858,
"doc_id": "213610858",
"n_citations": 278,
"n_key_citations": 0,
"score": 0,
"title": "Over 17% efficiency ternary organic solar cells enabled by two non fullerene acceptors working in an alloy like model",
"venue": "",
"year": 2020
},
{
"abstract": "Stability through oxysalts The stability of organic inorganic perovskite solar cells is limited by degradation from oxygen and water. Yang et al. show that in situ reaction of perovskites with sulfate or phosphate ions can create thin, strongly bonded lead oxysalt layers that protect defect sites. This layer also boosts charge carrier lifetimes that lead to a power conversion efficiency of more than 20% Encapsulated devices maintained about 97% of this efficiency with simulated solar irradiation for nearly 2 months at a realistic operation temperature of 65degC. Science, this issue p. 473 Thin lead oxysalt layers passivate hybrid perovskite surfaces under an ambient atmosphere and enhance solar cell efficiency. We show that converting the surfaces of lead halide perovskite to water insoluble lead (II) oxysalt through reaction with sulfate or phosphate ions can effectively stabilize the perovskite surface and bulk material. These capping lead oxysalt thin layers enhance the water resistance of the perovskite films by forming strong chemical bonds. The wide bandgap lead oxysalt layers also reduce the defect density on the perovskite surfaces by passivating undercoordinated surface lead centers, which are defect nucleating sites. Formation of the lead oxysalt layer increases the carrier recombination lifetime and boosts the efficiency of the solar cells to 21.1% Encapsulated devices stabilized by the lead oxysalt layers maintain 96.8% of their initial efficiency after operation at maximum power point under simulated air mass (AM) 1.5 G irradiation for 1200 hours at 65degC.",
"author_names": [
"Shuang Yang",
"Shangshang Chen",
"Edoardo Mosconi",
"Yanjun Fang",
"Xun Xiao",
"Congcong Wang",
"Yu Jie Zhou",
"Zhenhua Yu",
"Jingjing Zhao",
"Yongli Gao",
"Filippo De Angelis",
"Jinsong Huang"
],
"corpus_id": 199379915,
"doc_id": "199379915",
"n_citations": 293,
"n_key_citations": 0,
"score": 0,
"title": "Stabilizing halide perovskite surfaces for solar cell operation with wide bandgap lead oxysalts",
"venue": "Science",
"year": 2019
},
{
"abstract": "The remarkable development in photovoltaic (PV) technologies over the past 5 years calls for a renewed assessment of their performance and potential for future progress. Here, we analyse the progress in cells and modules based on single crystalline GaAs, Si, GaInP and InP, multicrystalline Si as well as thin films of polycrystalline CdTe and CuInxGa1 xSe2. In addition, we analyse the PV developments of the more recently emerged lead halide perovskites together with notable improvements in sustainable chalcogenides, organic PVs and quantum dots technologies. In addition to power conversion efficiencies, we consider many of the factors that affect power output for each cell type and note improvements in control over the optoelectronic quality of PV relevant materials and interfaces and the discovery of new material properties. By comparing PV cell parameters across technologies, we appraise how far each technology may progress in the near future. Although accurate or revolutionary developments cannot be predicted, cross fertilization between technologies often occurs, making achievements in one cell type an indicator of evolutionary developments in others. This knowledge transfer is timely, as the development of metal halide perovskites is helping to unite previously disparate, technology focused strands of PV research.Nearly all types of solar photovoltaic cells and technologies have developed dramatically, especially in the past 5 years. Here, we critically compare the different types of photovoltaic technologies, analyse the performance of the different cells and appraise possibilities for future technological progress.",
"author_names": [
"Pabitra K Nayak",
"Suhas Mahesh",
"Henry J Snaith",
"David Cahen"
],
"corpus_id": 141233525,
"doc_id": "141233525",
"n_citations": 286,
"n_key_citations": 1,
"score": 0,
"title": "Photovoltaic solar cell technologies: analysing the state of the art",
"venue": "Nature Reviews Materials",
"year": 2019
},
{
"abstract": "Stabilization of the crystal phase of inorganic/organic lead halide perovskites is critical for their high performance optoelectronic devices. However, due to the highly ionic nature of perovskite crystals, even phase stabilized polycrystalline perovskites can undergo undesirable phase transitions when exposed to a destabilizing environment. While various surface passivating agents have been developed to improve the device performance of perovskite solar cells, conventional deposition methods using a protic polar solvent, mainly isopropyl alcohol (IPA) results in a destabilization of the underlying perovskite layer and an undesirable degradation of device properties. We demonstrate the hidden role of IPA in surface treatments and develop a strategy in which the passivating agent is deposited without destabilizing the high quality perovskite underlayer. This strategy maximizes and stabilizes device performance by suppressing the formation of the perovskite d phase and amorphous phase during surface treatment, which is observed using conventional methods. Our strategy also effectively passivates surface and grain boundary defects, minimizing non radiative recombination sites, and preventing carrier quenching at the perovskite interface. This results in an open circuit voltage loss of only ~340 mV, a champion device with a power conversion efficiency of 23.4% from a reverse current voltage scan, a device with a record certified stabilized PCE of 22.6% and enhanced operational stability. In addition, our perovskite solar cell exhibits an electroluminescence external quantum efficiency up to 8.9%",
"author_names": [
"Jason J Yoo",
"Sarah Wieghold",
"Melany Sponseller",
"Matthew R Chua",
"Sophie N Bertram",
"Noor Titan Putri Hartono",
"Jason S Tresback",
"Eric C Hansen",
"Juan-Pablo Correa-Baena",
"Vladimir Bulovic",
"Tonio Buonassisi",
"Seong Sik Shin",
"Moungi G Bawendi"
],
"corpus_id": 196886304,
"doc_id": "196886304",
"n_citations": 213,
"n_key_citations": 1,
"score": 0,
"title": "An interface stabilized perovskite solar cell with high stabilized efficiency and low voltage loss",
"venue": "",
"year": 2019
},
{
"abstract": "Over the past few years, non fullerene organic solar cells have been a focus of research and their power conversion efficiencies have been improved dramatically from about 6 to over 14 In addition to innovations in non fullerene acceptors, the ongoing development of polymer donors has contributed significantly to the rapid progress of non fullerene organic solar cell performance. This Minireview highlights the polymer donors that enable high performance non fullerene organic solar cells. We show the impressive photovoltaic devices results achieved by some of important classes of conjugated polymer systems in non fullerene organic solar cells. We discuss the molecular design strategies as far as developing matching polymer donors for non fullerene acceptors. We conclude with a brief summary and outlook for advances in donor polymers required for commercialization.",
"author_names": [
"Huiting Fu",
"Zhaohui Wang",
"Yanming Sun"
],
"corpus_id": 52115360,
"doc_id": "52115360",
"n_citations": 207,
"n_key_citations": 0,
"score": 0,
"title": "Polymer Donors for High Performance Non Fullerene Organic Solar Cells.",
"venue": "Angewandte Chemie",
"year": 2019
},
{
"abstract": "Energy loss within organic solar cells (OSCs) is undesirable as it reduces cell efficiency 1 4 In particular, non radiative recombination loss 3 and energetic disorder 5 which are closely related to the tail states below the band edge and the overall photon energy loss, need to be minimized to improve cell performance. Here, we report how the use of a small molecule acceptor with torsion free molecular conformation can achieve a very low degree of energetic disorder and mitigate energy loss in OSCs. The resulting single junction OSC has an energy loss due to non radiative recombination of just 0.17 eV and a high power conversion efficiency of up to 16.54% (certified as 15.89% by the National Renewable Energy Laboratory) The findings take studies of organic photovoltaics deeper into a new regime, beyond the limits of energetic disorder and large energy offset for charge generation. An organic solar cell designed with minimal energetic disorder exhibits very low energy loss due to non radiative recombination and highly efficient operation.",
"author_names": [
"Shan Liu",
"Jun Yuan",
"Wanyuan Deng",
"Mei Luo",
"Yuan Xie",
"Quanbin Liang",
"Yingping Zou",
"Zhicai He",
"Hongbin Wu",
"Yong Cao"
],
"corpus_id": 213308210,
"doc_id": "213308210",
"n_citations": 242,
"n_key_citations": 0,
"score": 0,
"title": "High efficiency organic solar cells with low non radiative recombination loss and low energetic disorder",
"venue": "",
"year": 2020
}
] |
ghz ultrasound neural | [
{
"abstract": "Emergent trends in the device development for neural prosthetics have focused on establishing stimulus localization, improving longevity through immune compatibility, reducing energy re quirements, and embedding active control in the devices. Ultrasound stimulation can single handedly address several of these challenges. Ultrasonic stimulus of neurons has been studied extensively from 100 kHz to 10 MHz, with high penetration but less localization. In this paper, a chip scale device consisting of piezoelectric Aluminum Nitride ultrasonic transducers was engineered to deliver gigahertz (GHz) ultrasonic stimulus to the human neural cells. These devices provide a path towards complementary metal oxide semiconductor (CMOS) integration towards fully controllable neural devices. At GHz frequencies, ultrasonic wavelengths in water are a few microns and have an absorption depth of 10 20 um This confinement of energy can be used to control stimulation volume within a single neuron. This paper is the first proof of concept study to demonstrate that GHz ultrasound can stimulate neurons in vitro By utilizing optical calcium imaging, which records calcium ion flux indicating occurrence of an action potential, this paper demonstrates that an application of a nontoxic dosage of GHz ultrasonic waves \\ge 0.05\\frac{W}{c{m}{2} 0.05 W c m 2 caused an average normalized fluorescence intensity recordings >1.40 for the calcium transients. Electrical effects due to chip scale ultrasound delivery was discounted as the sole mechanism in stimulation, with effects tested at a 0.01 statistical significance amongst all intensities and con trol groups. Ionic transients recorded optically were confirmed to be mediated by ion channels and experimental data suggests an insignificant thermal contributions to stimulation, with a predicted increase of 0.03 o C for $1.2\\frac{W}{c{m}{2}\\cdot 1.2 W c m 2 This paper paves the experimental framework to further explore chip scale axon and neuron specific neural stimulation, with future applications in neural prosthetics, chip scale neural engineering, and extensions to different tissue and cell types.",
"author_names": [
"Priyadarshini Balasubramanian",
"Ashutosh Kumar Singh",
"Chris Xu",
"Amit Lal"
],
"corpus_id": 211194821,
"doc_id": "211194821",
"n_citations": 1,
"n_key_citations": 0,
"score": 1,
"title": "GHz Ultrasonic Chip Scale Device Induces Ion Channel Stimulation in Human Neural Cells",
"venue": "Scientific Reports",
"year": 2020
},
{
"abstract": "A novel neural stimulation system is demonstrated that is capable of delivering tunable ultrasonic stimulus at the cellular level and additionally providing feedback information towards dosage regulation. GHz aluminum nitride ultrasound transducers provide continuous wave stimulation to in vitro, retinoic acid differentiated SH SY5Y neuroblastoma cells at 1.05 GHz. Results show stimulation of optically recorded calcium ion transients in SH SY5Y cells, with during stimulation increases in FIFo of 1.5 0.328, differing from pre stimulation with p 0.01. The ultrasonic pulse echo return signal of the ultrasound transducer is used to estimate and tune the ultrasound dosage using transducer design, input stimulus, and interface medium. Results and theory suggest that higher acoustic impedance cell culture medium and scaffolds will allow for delivery of higher ultrasonic intensity to neural cells. Differences in echo return amplitudes for various interface medium and input stimulus amplitudes are reported at $a$ 0.01.",
"author_names": [
"Priyadarshini Balasubramanian",
"Amit Lal"
],
"corpus_id": 56596909,
"doc_id": "56596909",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Cellular Localization and Dosage Regulation of Neural Stimulation Enabled by 1.05 GHz Ultrasonics",
"venue": "2018 IEEE International Ultrasonics Symposium (IUS)",
"year": 2018
},
{
"abstract": "Abstract Failures in high voltage insulators can cause significant injuries for the consumers, since these piece of equipment play a fundamental role for the transmission lines operation. Insulator inspection and diagnosis techniques are widely researched, varying mainly regarding to the data collection method, as example: ultrasound, thermal imaging, leakage current, corona, electric field and RF signals. In this article, the RF signals radiated by the insulators were used to classify them into three levels of pollution: \"light\" \"medium\" and \"heavy\" For this, we used the standard IEC 60815 1 as reference, which takes into account the ESDD and NSDD indices. The proposed classification method was based on the wavelet transform, for signal processing, and artificial neural network for the classification. The success rate was approximately 95% in the 1.2 1.4 GHz frequency range.",
"author_names": [
"Pedro H V Rocha",
"Edson Guedes da Costa",
"Alexandre Jean Rene Serres",
"George Victor Rocha Xavier",
"J E B Peixoto",
"R L Lins"
],
"corpus_id": 191140035,
"doc_id": "191140035",
"n_citations": 6,
"n_key_citations": 0,
"score": 0,
"title": "Inspection in overhead insulators through the analysis of the irradiated RF spectrum",
"venue": "",
"year": 2019
},
{
"abstract": "In this article, two novel deep learning methods are proposed for displacement estimation in ultrasound elastography (USE) Although convolutional neural networks (CNNs) have been very successful for displacement estimation in computer vision, they have been rarely used for USE. One of the main limitations is that the radio frequency (RF) ultrasound data, which is crucial for precise displacement estimation, has vastly different frequency characteristics compared with images in computer vision. Top rank CNN methods used in computer vision applications are mostly based on a multilevel strategy, which estimates finer resolution based on coarser ones. This strategy does not work well for RF data due to its large high frequency content. To mitigate the problem, we propose modified pyramid warping and cost volume network (MPWC Net) and RFMPWC Net, both based on PWC Net, to exploit information in RF data by employing two different strategies. We obtained promising results using networks trained only on computer vision images. In the next step, we constructed a large ultrasound simulation database and proposed a new loss function to fine tune the network to improve its performance. The proposed networks and well known optical flow networks as well as state of the art elastography methods are evaluated using simulation, phantom, and in vivo data. Our two proposed networks substantially outperform current deep learning methods in terms of contrast to noise ratio (CNR) and strain ratio (SR) Also, the proposed methods perform similar to the state of the art elastography methods in terms of CNR and have better SR by substantially reducing the underestimation bias.",
"author_names": [
"Ali Kafaei Zad Tehrani",
"Hassan Rivaz"
],
"corpus_id": 211191318,
"doc_id": "211191318",
"n_citations": 17,
"n_key_citations": 2,
"score": 0,
"title": "Displacement Estimation in Ultrasound Elastography Using Pyramidal Convolutional Neural Network",
"venue": "IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control",
"year": 2020
},
{
"abstract": "We introduce an optimized physics informed neural network (PINN) trained to solve the problem of identifying and characterizing a surface breaking crack in a metal plate. PINNs are neural networks that can combine data and physics in the learning process by adding the residuals of a system of Partial Differential Equations to the loss function. Our PINN is supervised with realistic ultrasonic surface acoustic wave data acquired at a frequency of 5 MHz. The ultrasonic surface wave data is represented as a surface deformation on the top surface of a metal plate, measured by using the method of laser vibrometry. The PINN is physically informed by the acoustic wave equation and its convergence is sped up using adaptive activation functions. The adaptive activation function uses a scalable hyperparameter in the activation function, which is optimized to achieve best performance of the network as it changes dynamically the topology of the loss function involved in the optimization process. The usage of adaptive activation function significantly improves the convergence, notably observed in the current study. We use PINNs to estimate the speed of sound of the metal plate, which we do with an error of 1\\ and then, by allowing the speed of sound to be space dependent, we identify and characterize the crack as the positions where the speed of sound has decreased. Our study also shows the effect of sub sampling of the data on the sensitivity of sound speed estimates. More broadly, the resulting model shows a promising deep neural network model for ill posed inverse problems.",
"author_names": [
"Khemraj Shukla",
"Patricio Clark di Leoni",
"James L Blackshire",
"Daniel Murray Sparkman",
"George Em Karniadakis"
],
"corpus_id": 218537894,
"doc_id": "218537894",
"n_citations": 30,
"n_key_citations": 1,
"score": 0,
"title": "Physics informed neural network for ultrasound nondestructive quantification of surface breaking cracks",
"venue": "ArXiv",
"year": 2020
},
{
"abstract": "Multichannel electrophysiological sensors and stimulators, especially those used for studying the nervous system, are most commonly based on monolithic microelectrode arrays. Such architecture limits the spatial flexibility of individual electrode placement, posing constraints for scaling to a large number of nodes, particularly across non contiguous locations. We describe the design and fabrication of sub millimeter size electronic microchips \"Neurograins\" which autonomously perform neural sensing or electrical microstimulation, with emphasis on their wireless networking and powering. An ~1 GHz electromagnetic transcutaneous link to an external telecom hub enables bidirectional communication and control at the individual neurograin level. The link operates on a customized time division multiple access (TDMA) protocol designed to scale up to 1000 neurograins. The system is demonstrated as a cortical implant in a small animal (rat) model with anatomical limitations restricting the implant to 48 neurograins. We suggest that the neurograin approach can be generalized to overcome many scalability issues for wireless sensors and actuators as implantable microsystems.",
"author_names": [
"Jihun Lee",
"Vincent W Leung",
"Ah-Hyoung Lee",
"Jiannan Huang",
"Peter M Asbeck",
"Patrick P Mercier",
"Steven Shellhammer",
"Lawrence E Larson",
"Farah Laiwalla",
"Arto V Nurmikko"
],
"corpus_id": 221711759,
"doc_id": "221711759",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Wireless Ensembles of Sub mm Microimplants Communicating as a Network near 1 GHz in a Neural Application",
"venue": "",
"year": 2020
},
{
"abstract": "Accurate tracking of tissue motion is critically important for several ultrasound elastography methods. In this study, we investigate the feasibility of using three published convolution neural network (CNN) models built for optical flow (hereafter referred to as CNN based tracking) by the computer vision community for breast ultrasound strain elastography. Elastographic datasets produced by finite element and ultrasound simulations were used to retrain three published CNN models: FlowNet CSS, PWC Net, and LiteFlowNet. After retraining, the three improved CNN models were evaluated using computer simulated and tissue mimicking phantoms, and in vivo breast ultrasound data. CNN based tracking results were compared with two published two dimensional (2D) speckle tracking methods: coupled tracking and GLobal Ultrasound Elastography (GLUE) methods. Our preliminary data showed that, based on the Wilcoxon rank sum tests, the improvements due to retraining were statistically significant (p 0.05) for all three CNN models. We also found that the PWC Net model was the best neural network model for data investigated, and its overall performance was on par with the coupled tracking method. CNR values estimated from in vivo axial and lateral strain elastograms showed that the GLUE algorithm outperformed both the retrained PWC Net model and the coupled tracking method, though the GLUE algorithm exhibited some biases. The PWC Net model was also able to achieve approximately 45 frames/second for 2D speckle tracking data investigated.",
"author_names": [
"Bo Peng",
"Yuhong Xian",
"Quan Zhang",
"Jingfeng Jiang"
],
"corpus_id": 210947063,
"doc_id": "210947063",
"n_citations": 11,
"n_key_citations": 0,
"score": 0,
"title": "Neural network based Motion Tracking for Breast Ultrasound Strain Elastography: An Initial Assessment of Performance and Feasibility",
"venue": "Ultrasonic imaging",
"year": 2020
},
{
"abstract": "The measurement of human vital signs is a highly important task in a variety of environments and applications. Most notably, the electrocardiogram (ECG) is a versatile signal that could indicate various physical and psychological conditions, from signs of life to complex mental states. The measurement of the ECG relies on electrodes attached to the skin to acquire the electrical activity of the heart, which imposes certain limitations. Recently, due to the advancement of wireless technology, it has become possible to pick up heart activity in a contactless manner. Among the possible ways to wirelessly obtain information related to heart activity, methods based on mm wave radars proved to be the most accurate in detecting the small mechanical oscillations of the human chest resulting from heartbeats. In this paper, we presented a method based on a continuous wave Doppler radar coupled with an artificial neural network (ANN) to detect heartbeats as individual events. To keep the method computationally simple, the ANN took the raw radar signal as input, while the output was minimally processed, ensuring low latency operation <1 s) The performance of the proposed method was evaluated with respect to an ECG reference \"ground truth\" in an experiment involving 21 healthy volunteers, who were sitting on a cushioned seat and were refrained from making excessive body movements. The results indicated that the presented approach is viable for the fast detection of individual heartbeats without heavy signal preprocessing.",
"author_names": [
"Nebojsa Malesevic",
"Vladimir L Petrovic",
"Minja Belic",
"Christian Antfolk",
"Veljko R Mihajlovic",
"Milica M Jankovic"
],
"corpus_id": 216109872,
"doc_id": "216109872",
"n_citations": 7,
"n_key_citations": 1,
"score": 0,
"title": "Contactless Real Time Heartbeat Detection via 24 GHz Continuous Wave Doppler Radar Using Artificial Neural Networks",
"venue": "Sensors",
"year": 2020
},
{
"abstract": "To assist radiologists in breast cancer classification in automated breast ultrasound (ABUS) imaging, we propose a computer aided diagnosis based on a convolutional neural network (CNN) that classifies breast lesions as benign and malignant. The proposed CNN adopts a modified Inception v3 architecture to provide efficient feature extraction in ABUS imaging. Because the ABUS images can be visualized in transverse and coronal views, the proposed CNN provides an efficient way to extract multiview features from both views. The proposed CNN was trained and evaluated on 316 breast lesions (135 malignant and 181 benign) An observer performance test was conducted to compare five human reviewers' diagnostic performance before and after referring to the predicting outcomes of the proposed CNN. Our method achieved an area under the curve (AUC) value of 0.9468 with five folder cross validation, for which the sensitivity and specificity were 0.886 and 0.876, respectively. Compared with conventional machine learning based feature extraction schemes, particularly principal component analysis (PCA) and histogram of oriented gradients (HOG) our method achieved a significant improvement in classification performance. The proposed CNN achieved a >10% increased AUC value compared with PCA and HOG. During the observer performance test, the diagnostic results of all human reviewers had increased AUC values and sensitivities after referring to the classification results of the proposed CNN, and four of the five human reviewers' AUCs were significantly improved. The proposed CNN employing a multiview strategy showed promise for the diagnosis of breast cancer, and could be used as a second reviewer for increasing diagnostic reliability.",
"author_names": [
"Eun Jung Choi",
"Younhee Choi",
"Hao Zhang",
"Gong Yong Jin",
"Seok-Bum Ko"
],
"corpus_id": 211121874,
"doc_id": "211121874",
"n_citations": 18,
"n_key_citations": 1,
"score": 0,
"title": "Breast Cancer Classification in Automated Breast Ultrasound Using Multiview Convolutional Neural Network with Transfer Learning.",
"venue": "Ultrasound in medicine biology",
"year": 2020
},
{
"abstract": "BackgroundIn this study, images of 2450 benign thyroid nodules and 2557 malignant thyroid nodules were collected and labeled, and an automatic image recognition and diagnosis system was established by deep learning using the YOLOv2 neural network. The performance of the system in the diagnosis of thyroid nodules was evaluated, and the application value of artificial intelligence in clinical practice was investigated.MethodsThe ultrasound images of 276 patients were retrospectively selected. The diagnoses of the radiologists were determined according to the Thyroid Imaging Reporting and Data System; the images were automatically recognized and diagnosed by the established artificial intelligence system. Pathological diagnosis was the gold standard for the final diagnosis. The performances of the established system and the radiologists in diagnosing the benign and malignant thyroid nodules were compared.ResultsThe artificial intelligence diagnosis system correctly identified the lesion area, with an area under the receiver operating characteristic (ROC) curve of 0.902, which is higher than that of the radiologists (0.859) This finding indicates a higher diagnostic accuracy (p 0.0434) The sensitivity, positive predictive value, negative predictive value, and accuracy of the artificial intelligence diagnosis system for the diagnosis of malignant thyroid nodules were 90.5% 95.22% 80.99% and 90.31% respectively, and the performance did not significantly differ from that of the radiologists (p 0.05) The artificial intelligence diagnosis system had a higher specificity (89.91% vs 77.98% p 0.026).ConclusionsCompared with the performance of experienced radiologists, the artificial intelligence system has comparable sensitivity and accuracy for the diagnosis of malignant thyroid nodules and better diagnostic ability for benign thyroid nodules. As an auxiliary tool, this artificial intelligence diagnosis system can provide radiologists with sufficient assistance in the diagnosis of benign and malignant thyroid nodules.",
"author_names": [
"Lei Wang",
"Shujian Yang",
"Shanshan Yang",
"Cheng Zhao",
"Guangye Tian",
"Yuxiu Gao",
"Yongjian Chen",
"Yun Lu"
],
"corpus_id": 57783443,
"doc_id": "57783443",
"n_citations": 62,
"n_key_citations": 2,
"score": 0,
"title": "Automatic thyroid nodule recognition and diagnosis in ultrasound imaging with the YOLOv2 neural network",
"venue": "World Journal of Surgical Oncology",
"year": 2019
}
] |
, , , , , and , J. Am. Chem. Soc., 2010, 132, 11642–11648 | [
{
"abstract": "Electronic structure intrinsically controls the light absorbance, redox potential, charge carrier mobility, and consequently, photoreactivity of semiconductor photocatalysts. The conventional approach of modifying the electronic structure of a semiconductor photocatalyst for a wider absorption range by anion doping operates at the cost of reduced redox potentials and/or charge carrier mobility, so that its photoreactivity is usually limited and some important reactions may not occur at all. Here, we report sulfur doped graphitic C(3)N(4) (C(3)N(4 x)S(x) with a unique electronic structure that displays an increased valence bandwidth in combination with an elevated conduction band minimum and a slightly reduced absorbance. The C(3)N(4 x)S(x) shows a photoreactivity of H(2) evolution 7.2 and 8.0 times higher than C(3)N(4) under lambda 300 and 420 nm, respectively. More strikingly, the complete oxidation process of phenol under lambda 400 nm can occur for sulfur doped C(3)N(4) which is impossible for C(3)N(4) even under lambda 300 nm. The homogeneous substitution of sulfur for lattice nitrogen and a concomitant quantum confinement effect are identified as the cause of this unique electronic structure and, consequently, the excellent photoreactivity of C(3)N(4 x)S(x) The results acquired may shed light on general doping strategies for designing potentially efficient photocatalysts.",
"author_names": [
"Gang Liu",
"Ping Niu",
"Chenghua Sun",
"Sean C Smith",
"Zhigang Chen",
"Gao Q Lu",
"Hui-Ming Cheng"
],
"corpus_id": 29343205,
"doc_id": "29343205",
"n_citations": 1441,
"n_key_citations": 5,
"score": 1,
"title": "Unique electronic structure induced high photoreactivity of sulfur doped graphitic C3N4.",
"venue": "Journal of the American Chemical Society",
"year": 2010
},
{
"abstract": "To develop a highly efficient visible light induced and conveniently recyclable photocatalyst, in this study, a ternary magnetic ZnO/Fe3O4/g C3N4 composite photocatalyst was synthesized for the photodegradation of Monas dye. The structure and optical performance of the composite photocatalyst were characterized using X ray diffraction (XRD) transmission electron microscopye (TEM) energy dispersive spectroscopy (EDS) photoluminescence (PL) spectra, ultraviolet visible diffuse reflection, and photo electrochemistry. The photocatalytic activities of the prepared ZnO/Fe3O4/g C3N4 nanocomposites were notably improved, and they were significantly higher than those of pure g C3N4 and ZnO. Given the presence of the heterojunction between the interfaces of g C3N4 and ZnO, the higher response to visible light and separation efficiency of the photo induced electrons and holes enhanced the photocatalytic activities of the ZnO/Fe3O4/g C3N4 nanocomposites. The stability experiment revealed that ZnO/Fe3O4/g C3N4 50% demonstrates a relatively higher photocatalytic activity after 5 recycles. The degradation efficiency of MO, AYR, and OG over ZnO/Fe3O4/g C3N4 50% were 97.87% 98.05% and 83.35% respectively, which was due to the number of dye molecules adsorbed on the photocatalyst and the structure of the azo dye molecule. Azo dyes could be effectively and rapidly photodegraded by the obtained photocatalyst. Therefore, the environment friendly photocatalyst could be widely applied to the treatment of dye contaminated wastewater.",
"author_names": [
"Zhansheng Wu",
"Xiaoqin Chen",
"Xiaochen Liu",
"Xia Yang",
"Yan Yang"
],
"corpus_id": 140307182,
"doc_id": "140307182",
"n_citations": 30,
"n_key_citations": 0,
"score": 0,
"title": "A Ternary Magnetic Recyclable ZnO/Fe3O4/g C3N4 Composite Photocatalyst for Efficient Photodegradation of Monoazo Dye",
"venue": "Nanoscale Research Letters",
"year": 2019
},
{
"abstract": "Phosphorus doped hexagonal tubular carbon nitride (P TCN) with the layered stacking structure was obtained from a hexagonal rod like single crystal supramolecular precursor (monoclinic, C2/m) The production process of P TCN involves two steps: 1) the precursor was prepared by self assembly of melamine with cyanuric acid from in situ hydrolysis of melamine under phosphorous acid assisted hydrothermal conditions; 2) the pyrolysis was initiated at the center of precursor under heating, thus giving the hexagonal P TCN. The tubular structure favors the enhancement of light scattering and active sites. Meanwhile, the introduction of phosphorus leads to a narrow band gap and increased electric conductivity. Thus, the P TCN exhibited a high hydrogen evolution rate of 67 mmol h( 1) (0.1 g catalyst, l >420 nm) in the presence of sacrificial agents, and an apparent quantum efficiency of 5.68 at 420 nm, which is better than most of bulk g C3 N4 reported.",
"author_names": [
"Shien Guo",
"Zhao-Peng Deng",
"Mingxia Li",
"Baojiang Jiang",
"Chungui Tian",
"Qingjiang Pan",
"Honggang Fu"
],
"corpus_id": 39847337,
"doc_id": "39847337",
"n_citations": 566,
"n_key_citations": 0,
"score": 0,
"title": "Phosphorus Doped Carbon Nitride Tubes with a Layered Micro nanostructure for Enhanced Visible Light Photocatalytic Hydrogen Evolution.",
"venue": "Angewandte Chemie",
"year": 2016
},
{
"abstract": "Photocatalytic degradation by semiconductors is an ideal way to solve the environmental problem. Here, the porous Mn doped g C3N4 photocatalyst was synthesized by the calcination refluxing method. The as prepared g C3N4 exhibits the high activity of photocatalytic degradation under visible light irradiation 400nm) in the mixed system of Cr(VI) and organic pollutants. Especially, the photocatalytic activity of Cr(VI) reduction was increased from 9.5% to 76.5% while that of Rhodamine B(RhB) degradation was enhanced from 15.3% to 88.9% after 60min irradiation. The porous Mn doped g C3N4 still keeps the high degradation efficiency of mixed pollutants in the 7th running. Based on the computational modeling, the Mn doping and carboxyl modification affect the atomic arrangement and molecular orbital distribution of the g C3N4 semiconductor, leading to the enhancement of photo induced carrier separation. Additionally, the active oxygen species and intermediates in the photoreaction process were discovered by ESR measurement and UV vis test. The RhB degradation in synergistic photocatalysis not only inhibits the reverse reaction of Cr(VI) reduction, but also validly supply the photogenerated electrons by the photosensitization effect. This work may be useful for rationally designing photocatalysts and providing illuminating insights into the photocatalytic mechanism.",
"author_names": [
"Ji-Chao Wang",
"Cheng-Xing Cui",
"Yucheng Li",
"Lu Liu",
"Yu-Ping Zhang",
"Weina Shi"
],
"corpus_id": 11965301,
"doc_id": "11965301",
"n_citations": 88,
"n_key_citations": 0,
"score": 0,
"title": "Porous Mn doped g C3N4 photocatalysts for enhanced synergetic degradation under visible light illumination.",
"venue": "Journal of hazardous materials",
"year": 2017
},
{
"abstract": "The primary amine groups on the heptazine based polymer melon, also known as graphitic carbon nitride (g C3N4) can be replaced by urea groups using a two step postsynthetic functionalization. Under simulated sunlight and optimum Pt loading, this urea functionalized carbon nitride has one of the highest activities among organic and polymeric photocatalysts for hydrogen evolution with methanol as sacrificial donor, reaching an apparent quantum efficiency of 18% and nearly 30 times the hydrogen evolution rate compared to the nonfunctionalized counterpart. In the absence of Pt, the urea derivatized material evolves hydrogen at a rate over four times that of the nonfunctionalized one. Since \"defects\" are conventionally accepted to be the active sites in graphitic carbon nitride for photocatalysis, the work here is a demonstrated example of \"defect engineering,\" where the catalytically relevant defect is inserted rationally for improving the intrinsic, rather than extrinsic, photocatalytic performance. Furthermore, the work provides a retrodictive explanation for the general observation that g C3N4 prepared from urea performs better than those prepared from dicyandiamide and melamine. In depth analyses of the spent photocatalysts and computational modeling suggest that inserting the urea group causes a metal support interaction with the Pt cocatalyst, thus facilitating interfacial charge transfer to the hydrogen evolving centers.",
"author_names": [
"Vincent Wing-hei Lau",
"Victor Wen-zhe Yu",
"Florian Ehrat",
"Tiago Botari",
"Igor L Moudrakovski",
"Thomas Simon",
"Viola Duppel",
"Elise Medina",
"Jacek K Stolarczyk",
"Jochen Feldmann",
"Volker Blum",
"Bettina V Lotsch"
],
"corpus_id": 99943387,
"doc_id": "99943387",
"n_citations": 150,
"n_key_citations": 0,
"score": 0,
"title": "Urea Modified Carbon Nitrides: Enhancing Photocatalytic Hydrogen Evolution by Rational Defect Engineering",
"venue": "",
"year": 2017
},
{
"abstract": "The major challenge of photocatalytic water splitting, the prototypical reaction for the direct production of hydrogen by using solar energy, is to develop low cost yet highly efficient and stable semiconductor photocatalysts. Herein, an effective strategy for synthesizing extremely active graphitic carbon nitride (g C3N4) from a low cost precursor, urea, is reported. The g C3N4 exhibits an extraordinary hydrogen evolution rate (ca. 20 000 mmol h 1 g 1 under full arc) which leads to a high turnover number (TON) of over 641 after 6 h. The reaction proceeds for more than 30 h without activity loss and results in an internal quantum yield of 26.5 under visible light, which is nearly an order of magnitude higher than that observed for any other existing g C3N4 photocatalysts. Furthermore, it was found by experimental analysis and DFT calculations that as the degree of polymerization increases and the proton concentration decreases, the hydrogen evolution rate is significantly enhanced.",
"author_names": [
"David James Martin",
"Kaipei Qiu",
"Stephen Andrew Shevlin",
"Albertus Denny Handoko",
"Xiaowei Chen",
"Zhengxiao Guo",
"Junwang Tang"
],
"corpus_id": 10287121,
"doc_id": "10287121",
"n_citations": 768,
"n_key_citations": 4,
"score": 0,
"title": "Highly Efficient Photocatalytic H2 Evolution from Water using Visible Light and Structure Controlled Graphitic Carbon Nitride*",
"venue": "Angewandte Chemie",
"year": 2014
},
{
"abstract": "A new type of boron doped graphitic carbon nitride (B g C3N4) nanosheets was prepared by a benign one pot thermal polycondensation process. Systematic studies revealed that a B doping amount of 1 at% into g C3N4 (1at%B g C3N4) showed the best photocatalytic H2 evolution activity of 1880 mmol h 1 g 1 under visible light irradiation >400 nm) which is more than 12 times that of the pristine g C3N4 bulk. Detailed characterizations revealed that the high photocatalytic performance could be attributed to the combination of band structure engineering and morphological control. B doping not only reduces the band gap to absorb more visible light but also exhibits a higher surface area of B g C3N4 (49.47 m2 g 1) as compared to that of g C3N4 bulk (8.24 m2 g 1) which subsequently improve the photocatalytic performance drastically. This work demonstrates a synergistic strategy to prepare efficient metal free B g C3N4 nanosheets as a promising photocatalyst for H2 evolution under visible light with good stability.",
"author_names": [
"Supphasin Thaweesak",
"Songcan Wang",
"Miaoqiang Lyu",
"Mu Xiao",
"Piangjai Peerakiatkhajohn",
"Lianzhong Wang"
],
"corpus_id": 206088924,
"doc_id": "206088924",
"n_citations": 87,
"n_key_citations": 0,
"score": 0,
"title": "Boron doped graphitic carbon nitride nanosheets for enhanced visible light photocatalytic water splitting.",
"venue": "Dalton transactions",
"year": 2017
},
{
"abstract": "Graphitic carbon nitride (g C(3)N(4) as an intriguing earth abundant visible light photocatalyst, possesses a unique two dimensional structure, excellent chemical stability and tunable electronic structure. Pure g C(3)N(4) suffers from rapid recombination of photo generated electron hole pairs resulting in low photocatalytic activity. Because of the unique electronic structure, the g C(3)N(4) could act as an eminent candidate for coupling with various functional materials to enhance the performance. According to the discrepancies in the photocatalytic mechanism and process, six primary systems of g C(3)N(4) based nanocomposites can be classified and summarized: namely, the g C(3)N(4) based metal free heterojunction, the g C(3)N(4)/single metal oxide (metal sulfide) heterojunction, g C(3)N(4)/composite oxide, the g C(3)N(4)/halide heterojunction, g C(3)N(4)/noble metal heterostructures, and the g C(3)N(4) based complex system. Apart from the depiction of the fabrication methods, heterojunction structure and multifunctional application of the g C(3)N(4) based nanocomposites, we emphasize and elaborate on the underlying mechanisms in the photocatalytic activity enhancement of g C(3)N(4) based nanocomposites. The unique functions of the p n junction (semiconductor/semiconductor heterostructures) the Schottky junction (metal/semiconductor heterostructures) the surface plasmon resonance (SPR) effect, photosensitization, superconductivity, etc. are utilized in the photocatalytic processes. Furthermore, the enhanced performance of g C(3)N(4) based nanocomposites has been widely employed in environmental and energetic applications such as photocatalytic degradation of pollutants, photocatalytic hydrogen generation, carbon dioxide reduction, disinfection, and supercapacitors. This critical review ends with a summary and some perspectives on the challenges and new directions in exploring g C(3)N(4) based advanced nanomaterials.",
"author_names": [
"Zaiwang Zhao",
"Yanjuan Sun",
"Fan Dong"
],
"corpus_id": 205919087,
"doc_id": "205919087",
"n_citations": 1029,
"n_key_citations": 3,
"score": 0,
"title": "Graphitic carbon nitride based nanocomposites: a review.",
"venue": "Nanoscale",
"year": 2015
},
{
"abstract": "A heterogeneous WS2/g C3N4 composite photocatalyst was prepared by a facile ultrasound assisted hydrothermal method. The WS2/g C3N4 composite was used for photocatalytic regeneration of NAD+ to NADH, which were coupled with dehydrogenases for sustainable bioconversion of CO2 to methanol under visible light irradiation. Compared with pristine g C3N4 and the physical mixture of WS2 and g C3N4, the fabricated WS2/g C3N4 composite catalyst with 5 wt% of WS2 showed the highest activity for methanol synthesis. The methanol productivity reached 372.1 mmol h 1 gcat 1, which is approximately 7.5 times higher than that obtained using pure g C3N4. For further application demonstration, the activity of the WS2/g C3N4 composite catalyst toward photodegradation of Rhodamine B (RhB) was evaluated. RhB removal ratio approaching 100% was achieved in 1 hour by using the WS2/g C3N4 composite catalyst with 5 wt% of WS2, at an apparent degradation rate approximately 2.6 times higher than that of pure g C3N4. Based on detailed investigations on physiochemical properties of the photocatalysts, the significantly enhanced reaction efficiency of the WS2/g C3N4 composite was considered to be mainly benefiting from the formation of a heterojunction interface between WS2 and g C3N4. Upon visible light irradiation, the photo induced electrons can transfer from the conduction band of g C3N4 to WS2, thus recombination of electrons and holes was decreased and the photo harvesting efficiency was enhanced.",
"author_names": [
"Peng Zeng",
"Xiaoyuan Ji",
"Zhi-guo Su",
"Songping Zhang"
],
"corpus_id": 103761791,
"doc_id": "103761791",
"n_citations": 14,
"n_key_citations": 0,
"score": 0,
"title": "WS2/g C3N4 composite as an efficient heterojunction photocatalyst for biocatalyzed artificial photosynthesis",
"venue": "",
"year": 2018
},
{
"abstract": "Novel photocatalysts CdSe quantum dots (QDs)/g C3N4 were successfully constructed. The structure, chemical composition, and optical properties of the prepared samples were investigated via a series of characterization techniques. The results indicated that CdSe QDs/g C3N4 photocatalysts exhibited remarkably enhanced photocatalytic activity for visible light induced H2 evolution compared to pristine g C3N4 and CdSe QDs and addition of 13.6 wt CdSe QDs into the composite photocatalyst generated the highest H2 production rate. The enhanced photocatalytic performance of CdSe QDs/g C3N4 can be attributed to the synergistic effects of excellent visible absorption and high charge separation efficiency from the heterostructure. This work could not only provide a facile method to fabricate semiconductor QDs modified g C3N4 photocatalysts but also contribute to the design for heterostructures.",
"author_names": [
"Yunqian Zhong",
"Weiwei Chen",
"Shan Yu",
"Zhang-hui Xie",
"Shiqiang Wei",
"Ying Zhou"
],
"corpus_id": 139482996,
"doc_id": "139482996",
"n_citations": 17,
"n_key_citations": 0,
"score": 0,
"title": "CdSe Quantum Dots/g C3N4 Heterostructure for Efficient H2 Production under Visible Light Irradiation",
"venue": "ACS omega",
"year": 2018
}
] |
secom case study | [
{
"abstract": "Abstract The big data samples are important source for analytics. However, its relevant/irrelevant information, unspecified variables/scales, noise/null, and so forth impose huge challenges on the analysis of relevance, feature, cause, and evaluation. This paper proposes an evidential analytics to disclose buried information in big data samples. Technically, it models memberships composed of relevant preference and replaces data with these priors. Its operations include generating analytics baselines, reducing variables, identifying sparse features, and inducing rules by taking advantage of evidence. In illustration, a case study of semiconductor manufacturing in UCI secom is presented. It discloses relevant signals, key factors, variables' thresholds, sparse characteristics, and causal effect of damages buried in normal samples. The contribution of this paper not only contains these achievements but provides priori data for inference.",
"author_names": [
"Yu-Chien Ko",
"Hamido Fujita"
],
"corpus_id": 93003594,
"doc_id": "93003594",
"n_citations": 10,
"n_key_citations": 0,
"score": 1,
"title": "An evidential analytics for buried information in big data samples: Case study of semiconductor manufacturing",
"venue": "Inf. Sci.",
"year": 2019
},
{
"abstract": "The purpose of this project paper was to identify the relationship between job satisfactions with the intention to leave among security personnel within Secom (Malaysia) Sdn. Bhd. a security service provider located in Shah Alam, Selangor. This study is aimed to identify the most high impact job satisfactions facets or dimension on the intention to leave the organization. It is also to identify the significant differences between studied demographic characteristics with the intention to leave among respondents. A questionnaire consists of six (6) facets of satisfaction developed by Wood et al. (1986) and Purani and Sahadev (2007) was used to measure job satisfaction with the intention to leave. The research is done via survey which inclusive of total of 57 questions for all facets or dimensions of job satisfaction and intention to leave; as well as their demographic characteristics. The data was analyzed by using the SPSS version 20.0. Respondents participated in the project paper was selected among security personnel of Secom (Malaysia) Sdn. Bhd. located throughout Malaysia. These employees were coming from various races, age group, marital status, years of working experience and academic levels. The findings indicate that there is a relationship between job satisfaction facets and the intention to leave. To add, satisfaction with supervisor and satisfaction to the management and human resource policies are said to have significant contribution and turns to be the dominant factor and has the highest impact to the intention to leave among security personnel in Secom (Malaysia) Sdn. Bhd. It was also found that different age group, marital status and education levels have significant differences with the intention to leave among respondents",
"author_names": [
"Amer Norazuana"
],
"corpus_id": 147232629,
"doc_id": "147232629",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "The relationship between job satisfaction and intention to leave among security personnel A case study at SECOM (Malaysia) Sdn Bhd",
"venue": "",
"year": 2013
},
{
"abstract": "Objective: To present a case of sclerosing polycystic adenosis (SPA) of the parotid gland, highlighting the probable etiology and the benign behavior of these cases. Case report: A woman of 22 years old had a right parotid mass with a slowly progressive growth associated with a chronic infection due to Epstein Barr virus. Initially, it was asymptomatic and subsequently the patient developed light dysesthesias in the region. A superficial parotidectomy was done and the microscopic study informed SPA. Conclusion: The SPA is similar to the fibrocystic changes, sclerosing adenosis and adenoid tumors of the mammary gland. The main location of the SPA is the parotid gland and it is considered a disease due to a pseudotumoral inflammatory reaction with a possible association with the Epstein Barr virus. There is evidence that monoclonal cell populations exist. The treatment consists in excision of the tumor with a superficial parotidectomy, which has demonstrated high cure rates. (c) 2014 SECOM. Published by Elsevier Espana, S.L.U. This is an open access article under the CC BY NC ND license (http:/creativecommons.org/licenses/by nc nd/4.0/ Adenosis Poliquistica Esclerosante de la Glandula Parotida: Un tumor raro aparentemente benigno alabras clave: denosis poliquistica esclerosante landula parotida r e s u m e n Objetivo: Presentar un caso de adenosis poliquistica esclerosante (APE) de la glandula parotida, destacando la etiologia probable y el comportamiento benigno de estos casos. Caso clinico: Mujer de 22 anos con una masa parotidea derecha de crecimiento lentamente pstein Barr virus arotidectomia superficial progresivo asociada con una infeccion cronica por el virus de Epstein Barr. Inicialmente, era asintomatica y posteriormente desarrollo disestesias ligeras en la region. Se realiza una parotidectomia superficial y el resultado histopatologico es de APE. Conclusion: La APE muestra cambios histopatologicos similares a los hallados en la enfermedad fibroquistica, adenosis esclerosante y los tumores adenoideos de la glandula Corresponding author. E mail address: hugo lara [email protected] (H. Lara Sanchez) ttp:/dx.doi.org/10.1016/j.maxilo.2014.07.009 130 0558/(c) 2014 SECOM. Published by Elsevier Espana, S.L.U. This is an open access article under the CC BY NC ND license http:/creativecommons.org/licenses/by nc nd/4.0/ 240 r e v e s p c i r o r a l m a x i l o f a c 2 0 1 5;3 7(4):239 242 mamaria. La ubicacion salivar principal de la APE es la glandula parotida y se trata de una enfermedad causada por una reaccion inflamatoria pseudotumoral con una posible asociacion con el virus de Epstein Barr. Hay pruebas de que existen poblaciones celulares monoclonales. El tratamiento de eleccion es quirurgico, siendo la parotidectomia superficial la tecnica de eleccion al haber demostrado tasas de curacion elevadas. (c) 2014 SECOM. Publicado por Elsevier Espana, S.L.U. Este es un articulo Open Access cia C Document downloaded from http:/www.elsevier.es, day 08/11/2018. This copy is for personal use. Any transmission of this document by any media or format is strictly prohibited.",
"author_names": [
"Erita Cordero",
"Roberto Pantoja",
"C N Pacheco",
"Sebastian Hudson Correa",
"R Munoz Carrasco",
"y Luis Carreno"
],
"corpus_id": 53572023,
"doc_id": "53572023",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "clerosing polycystic adenosis of the parotid gland",
"venue": "",
"year": 2014
},
{
"abstract": "Recently, TOD gains popularity as a traffic solution measure of high density urban regeneration projects. The purpose of this study is to investigate traffic impacts of high density TOD projects, and to identify the issues to be resolved. For a case study, it chooses Gangnamgucheong station in Gangnam area served by two subway lines, and designates 400m radius from the station as a site for high density development. The MOEs chosen for this study is traffic volume, time, distance, speed, and mode share. The SECOM model is adopted for traffic simulation. The analysis results show that high density TOD is an effective tool for traffic improvement even with only one station area being implemented. It is found that the traffic volume increases near the station in nature where high density development occurs, but it declines overall in the rest of Gangam area. The total travel time and distance of passenger vehicles decline, meaning that the traffic condition becomes better than before. With regulation on parking supply, the improvement becomes more vivid. In terms of the changes of traffic speed, both alternatives show 4.1% increase in speed, but the difference between alternatives is not quite noticeable because of the induced vehicle demand driven to the streets with improved traffic condition. The mode share changes occur for the benefit of subway ridership, because the study station is equipped with two subway line services. When mixed with parking supply restriction, the impact becomes clearer.",
"author_names": [
"Kee Yeon Hwang",
"Yong Hak Cho"
],
"corpus_id": 106579742,
"doc_id": "106579742",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Traffic Impacts of Transit oriented Urban Regeneration",
"venue": "",
"year": 2008
},
{
"abstract": "Recently, TOD gains popularity as a traffic solution measure of high density urban regeneration projects. The purpose of this study is to investigate traffic impacts of high density TOD projects, and to identify the issues to be resolved. For a case study, it chooses Gangnamgucheong station in Gangnam area served by two subway lines, and designates 400m radius from the station as a site for high density development. The MOEs chosen for this study is traffic volume, time, distance, speed, and mode share. The SECOM model is adopted for traffic simulation. The analysis results show that high density TOD is an effective tool for traffic improvement even with only one station area being implemented. It is found that the traffic volume increases near the station in nature where high density development occurs, but it declines overall in the rest of Gangam area. The total travel time and distance of passenger vehicles decline, meaning that the traffic condition becomes better than before. With regulation on parking supply, the improvement becomes more vivid. In terms of the changes of traffic speed, both alternatives show 4.1 increase in speed, but the difference between alternatives is not quite noticeable because of the induced vehicle demand driven to the streets with improved traffic condition. The mode share changes occur for the benefit of subway ridership, because the study station is equipped with two subway line services. When mixed with parking supply restriction, the impact becomes clearer.",
"author_names": [
""
],
"corpus_id": 108616325,
"doc_id": "108616325",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "TODhyeong dosijaesaengsaeobyi gyotongyeonghyang bunseog",
"venue": "",
"year": 2008
},
{
"abstract": "A 41 year old female with schizo affective disorder presenting with an eight year history of auditory hallucinations participated in a single case treatment study (A B A B A C B) of the effects of the Attention Training Technique (ATT) No antipsychotic medication was prescribed in this case following a serious adverse reaction in the past. The aim of the study was to test the impact of ATT on the frequency and duration of hallucinations using a repeated return to baseline followed by an alternating treatment design. The alternative intervention consisted of autogenic relaxation instructions. The patient monitored the frequency, duration, and her distress over the voices on a daily basis during baseline and intervention phases across a study period of 80 weeks. Visual analysis of the data showed that ATT when introduced at three phases following baselines or control conditions was associated with a reduction in auditory hallucination frequency and duration compared to the other phases. This contrasted with the autogenic relaxation intervention that was associated with an increase in duration and frequency of voices. The perceived benefits of ATT were maintained for varying periods of time.",
"author_names": [
"Karin E P Carter",
"Adrian Wells"
],
"corpus_id": 52142807,
"doc_id": "52142807",
"n_citations": 6,
"n_key_citations": 1,
"score": 0,
"title": "Effects of the Attention Training Technique on Auditory Hallucinations in Schizo Affective Disorder: A Single Case Study",
"venue": "Case reports in psychiatry",
"year": 2018
},
{
"abstract": "Kodamaea ohmeri is a relatively rare yeast isolated form clinical specimens, and it is known to be a causative fungus of severe invasive infectious diseases in immunocompromised hosts. Herein, we describe fungemia due to K. ohmeri in a patient with a severe extended burn. The isolate was obtained from not only blood specimens but also skin lesions. We should be aware of risk for fungemia including K. ohmeri in case of severe burn.",
"author_names": [
"Ayaka Tashiro",
"Takahito Nei",
"Ryoji Sugimoto",
"Akiko Watanabe",
"Jun Hagiwara",
"Toru Takiguchi",
"Hiroyuki Yokota",
"Katsuhiko Kamei"
],
"corpus_id": 51942167,
"doc_id": "51942167",
"n_citations": 13,
"n_key_citations": 2,
"score": 0,
"title": "Kodamaea ohmeri fungemia in severe burn: Case study and literature review",
"venue": "Medical mycology case reports",
"year": 2018
},
{
"abstract": "Background Stromal vascular fraction (SVF) is a mixture of adipose derived stem cells/mesenchymal stem cells, endothelial/progenitors, pericytes, fibroblasts, and other cells obtained from fat tissue. A small sample of fat or adipose tissue can be obtained under local anesthesia using a cannula. After an enzymatic digestion and centrifugation, the adipocytes (fat cells) are removed to obtain an SVF. Here, we describe the rationale and, to our knowledge, the first clinical implementation of SVF intravenously in a patient with severe psoriasis. Methods Adipose tissue (60 mL) was collected under local anesthesia via a mini lipoaspirate procedure. The SVF was separated from the adipocytes via centrifugation after an enzymatic digestion. The cells were resuspended in normal saline and injected via bolus push intravenous. The subject was monitored over a period of 12 months for safety (adverse events) medication changes, and quality of life parameters. Results The patient did not report any safety concerns and did not experience any severe adverse events. The patient demonstrated a significant decrease in symptoms with a noticeable difference in skin quality appearance. Psoriasis area and severity index score went from 50.4 at baseline to 0.3 at 1 month follow up. Conclusion Overall, the patient reported improved quality of life and willingness to continue treatments. This successful initial case study demonstrates that this may be a feasible treatment plan for patients suffering from psoriasis.",
"author_names": [
"Kristin Comella",
"Michelle Parlo",
"Rosemary Daly",
"Kellie Dominessy"
],
"corpus_id": 4515395,
"doc_id": "4515395",
"n_citations": 12,
"n_key_citations": 1,
"score": 0,
"title": "First in man intravenous implantation of stromal vascular fraction in psoriasis: a case study",
"venue": "International medical case reports journal",
"year": 2018
},
{
"abstract": "&NA; The emergence of liquid biopsy using circulating tumor cells (CTCs) as a resource to identify genomic alterations in cancer presents new opportunities for diagnosis, therapy, and surveillance. We identified EML4 ALK gene rearrangement in expanded CTCs from a patient with ALK positive lung adenocarcinoma. At the time of radiographic progression, CTCs obtained from the patient revealed a drug resistance mutation (i.e. L1196M on the ALK gene) CTCs were expanded ex vivo and drug sensitivity testing was performed using two ALK inhibitors, crizotinib and ceritinib. The half maximal inhibitory concentration of ceritinib was 1664 nM compared with crizotinib (2268 nM) showing that ceritinib was a more potent ALK inhibitor. We show that it is feasible to detect serial genetic alterations in expanded CTCs and perform in vitro drug screening. These findings support the clinical utility of CTCs not only for diagnosis, but also a potential tool for drug sensitivity testing in distinct subsets of lung cancer and for personalized precision medicine.",
"author_names": [
"Zhuo-jun Zhang",
"Hiroe Shiratsuchi",
"Nallasivam Palanisamy",
"Sunitha Nagrath",
"Nithya Ramnath"
],
"corpus_id": 46860606,
"doc_id": "46860606",
"n_citations": 30,
"n_key_citations": 2,
"score": 0,
"title": "Expanded Circulating Tumor Cells from a Patient with ALK Positive Lung Cancer Present with EML4 ALK Rearrangement Along with Resistance Mutation and Enable Drug Sensitivity Testing: A Case Study",
"venue": "Journal of thoracic oncology official publication of the International Association for the Study of Lung Cancer",
"year": 2017
},
{
"abstract": "Pulmonary seed embolization is a complication of prostatic brachytherapy with varying incidence rates. Key factors that reportedly influence the incidence of seed embolization include planning volume, quantity of seeds, seed placement, and type of seeds (stranded vs free) The clinical implications of seed migration are unclear because sequelae were not demonstrated in multiple short term studies yet there have been several reports of long term complications. We report a case of a 56 year old patient who presented with dyspnea approximately 6 years after brachytherapy treatment for a very low risk prostate cancer. Chest radiograph showed multiple linear densities overlying the right suprahilar lung. Computed tomography confirmed the location of the densities within the pulmonary arteries in the right upper lobe.",
"author_names": [
"Alexander D Calvert",
"Andrew W Dyer",
"Van A Montgomery"
],
"corpus_id": 18749447,
"doc_id": "18749447",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Embolization of prostatic brachytherapy seeds to pulmonary arteries: a case study",
"venue": "Radiology case reports",
"year": 2017
}
] |
Reconfigurable and programmable System-On-Chip hardware platform for real-time ultrasonic testing applications | [
{
"abstract": "Present day ultrasonic signal processing applications such as medical imaging and non destructive testing has stringent requirements on low cost and portability to provide high quality diagnostics and characterization at real time pace. Advancements in the field of digital signal processing, embedded computing, and semiconductor technologies, have significantly assisted ultrasound researchers in the development of low cost, portable, and computationally efficient systems. In this study, a reconfigurable and programmable ultrasonic testing system (RPUTS) is designed and developed to effortlessly test and evaluate a wide variety of ultrasonic signal processing applications. RPUTS integrates a reconfigurable Analog Front End (AFE) which supports up to 8 transducers suitable for phased array implementations. The back end processing is provided by Xilinx Zynq System on Chip (SoC) which includes a powerful embedded ARM processor. Zynq SoC manages the overall system configuration as well as the execution of the signal processing algorithms. This study demonstrates the capabilities of RPUTS by realizing a complete ultrasonic testing system which acquires ultrasonic data and performs high speed 3D compression on the acquired data at real time rate.",
"author_names": [
"Pramod Govindan",
"Boyang Wang",
"Pingping Wu",
"Ivan Palkov",
"Vidya Vasudevan",
"Jafar Saniie"
],
"corpus_id": 19403771,
"doc_id": "19403771",
"n_citations": 5,
"n_key_citations": 0,
"score": 1,
"title": "Reconfigurable and programmable System On Chip hardware platform for real time ultrasonic testing applications",
"venue": "2015 IEEE International Ultrasonics Symposium (IUS)",
"year": 2015
},
{
"abstract": "Ultrasonic testing systems have been extensively used in medical imaging and non destructive testing applications. Generally, these systems aim at a particular application or target material. To make these systems portable and more adaptable to the test environments, this study presents a reconfigurable ultrasonic testing system (RUTS) which possesses dynamic reconfiguration capabilities. RUTS consists a fully programmable Analog Front End (AFE) which facilitates beamforming and signal conditioning for variety of applications. RUTS AFE supports up to 8 transducers for phased array implementation. Xilinx Zynq System on Chip (SoC) based Zedboard provides the back end processing of RUTS. The powerful ARM embedded processor available within Zynq SoC manages the ultrasonic data acquisition/processing and overall system control, which makes RUTS a unique platform for the ultrasonic researchers to experiment and evaluate a wide range of real time ultrasonic signal processing applications. This Linux based system is utilized for ultra sonic data compression implementation providing a versatile environment for further development of ultrasonic imaging and testing system. Furthermore, this study demonstrates the capabilities of RUTS by performing ultrasonic data acquisition and data compression in real time. Thus, this reconfigurable system enables ultrasonic designers and researchers to efficiently prototype different experiments and to incorporate and analyze high performance ultrasonic signal and image processing algorithms.",
"author_names": [
"Pramod Govindan",
"Vidya Vasudevan",
"Thomas Gonnot",
"Jafar Saniie"
],
"corpus_id": 37399967,
"doc_id": "37399967",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Reconfigurable Ultrasonic Testing System Development Using Programmable Analog Front End and Reconfigurable System on Chip Hardware",
"venue": "",
"year": 2015
},
{
"abstract": "This study presents a scheme for enhancing the capabilities of an ultrasonic hardware platform leading to a fully reconfigurable system allowing for dynamic control over the analog front end. This system presents a robust approach for nondestructive testing, data analysis and imaging applications. The fully programmable analog front end system proposed in this paper supports up to 8 ultrasonic sensors. The components of this system are dynamically configurable by a Zynq system on chip (SoC) module for real time ultrasonic data acquisition and analysis. This reconfigurable system enables ultrasonic researchers to efficiently prototype different experiments and to incorporate high performance ultrasonic signal and image processing algorithms.",
"author_names": [
"Vidya Vasudevan",
"Pramod Govindan",
"Jafar Saniie"
],
"corpus_id": 20069851,
"doc_id": "20069851",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Programmable analog front end system for ultrasonic SoC hardware",
"venue": "IEEE International Conference on Electro/Information Technology",
"year": 2014
},
{
"abstract": "Ultrasonic signal processing applications require huge amounts of data to be processed. Further, high computational performance is essential to meet the real time requirements. Compression of the signal helps to reduce the data size and storage requirements as well as allow for rapid transmission of data to remote locations. High signal fidelity is significant in many of practical applications like ultrasound medical imaging and nondestructive testing. In this study, we discuss two methods for ultrasonic signal compression which offer high signal fidelity Discrete Wavelet Transform and signal decimation with the Nyquist rate limit. The compression algorithm is implemented on a reconfigurable system on chip platform using programmable hardware logic as well as in software using an embedded processor. The implementation details and the performance of the compression algorithms on both the hardware and software are analyzed in this paper.",
"author_names": [
"Pramod Govindan",
"Thomas Gonnot",
"Spenser Gilliland",
"Jafar Saniie"
],
"corpus_id": 24341185,
"doc_id": "24341185",
"n_citations": 6,
"n_key_citations": 2,
"score": 0,
"title": "3D ultrasonic signal compression algorithms for high signal fidelity",
"venue": "2013 IEEE 56th International Midwest Symposium on Circuits and Systems (MWSCAS)",
"year": 2013
},
{
"abstract": "Abstract. Hyperspectral instruments have been incorporated in satellite missions, providing large amounts of data of high spectral resolution of the Earth surface. This data can be used in remote sensing applications that often require a real time or near real time response. To avoid delays between hyperspectral image acquisition and its interpretation, the last usually done on a ground station, onboard systems have emerged to process data, reducing the volume of information to transfer from the satellite to the ground station. For this purpose, compact reconfigurable hardware modules, such as field programmable gate arrays (FPGAs) are widely used. This paper proposes an FPGA based architecture for hyperspectral unmixing. This method based on the vertex component analysis (VCA) and it works without a dimensionality reduction preprocessing step. The architecture has been designed for a low cost Xilinx Zynq board with a Zynq 7020 system on chip FPGA based on the Artix 7 FPGA programmable logic and tested using real hyperspectral data. Experimental results indicate that the proposed implementation can achieve real time processing, while maintaining the methods accuracy, which indicate the potential of the proposed platform to implement high performance, low cost embedded systems, opening perspectives for onboard hyperspectral image processing.",
"author_names": [
"Jose M P Nascimento",
"Mario Pereira Vestias"
],
"corpus_id": 124315407,
"doc_id": "124315407",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "System on chip field programmable gate array design for onboard real time hyperspectral unmixing",
"venue": "",
"year": 2016
},
{
"abstract": "The field of Internet of Things (IoT) and smart sensors has expanded rapidly in various fields of research and industrial applications. The area of IoT robotics has become a critical component in the evolution of Industry 4.0 standard. In this paper, we developed an IoT based reconfigurable System on Chip (SoC) robot that is fast and efficient for computer vision applications. It can be deployed in other IoT robotics applications and achieve its intended function. A Terasic Hexapod Spider Robot (TSR) was used with its DE0 Nano SoC board to implement our IoT robotics system. The TSR was designed to provide a competent computer vision application to recognize different shapes using a machine learning classifier. The data processing for image detection was divided into two parts, the first part involves hardware implementation on the SoC board and to provide real time interaction of the robot with the surrounding environment. The second part of implementation is based on the cloud processing technique, where further data analysis was performed. The image detection algorithm for the computer vision component was tested and successfully implemented to recognize shapes. The TSR moves or reacts based on the detected image. The Field Programmable Gate Array (FPGA) part is programmed to handle the movement of the robot and the Hard Processor System (HPS) handles the shape recognition, Wi Fi connectivity, and Bluetooth communication. This design is implemented, tested and can be used in real time applications in harsh environments where movements of other robots are restricted.",
"author_names": [
"Naheel Faisal Kamal",
"Mazen Abdelfattah",
"Marouane Ferjani",
"Abbes Amira",
"Naveed Nawaz"
],
"corpus_id": 211057650,
"doc_id": "211057650",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "An IoT Reconfigurable SoC Platform for Computer Vision Applications",
"venue": "2019 International Symposium on Systems Engineering (ISSE)",
"year": 2019
},
{
"abstract": "Ultrasonic industrial and medical imaging applications involve acquisition of large amount of volumetric data in real time. Therefore, data storage becomes critical in many current day applications which utilise ultrasound technology. Compressing the acquired data allows possessing minimal storage and also helps to rapidly transmit information to remote locations for expert analysis. The objective of this study is to design computationally efficient architectures for implementing discrete wavelet transform based ultrasonic three dimensional (3D) data compression algorithm on a reconfigurable ultrasonic system on chip (SoC) hardware platform. In this study, hardware and software architectures of the 3D ultrasonic compression algorithm are realised using Xilinx Zynq all programmable SoC. This study demonstrates that, compressing 33 MB of experimental ultrasonic 3D data into 0.42 MB (98.7% compression) requires only 84 ms for hardware architecture, and 1 min for software architecture, making both designs highly suitable for real time ultrasonic imaging applications. Furthermore, the 3D compression is implemented by using Open Computing Language (OpenCL) targeted on Nvidia GT 750M graphical processing unit. OpenCL implementation of ultrasonic 3D compression algorithm completes the execution in <1 sec. This approach provides improved computational performance as that of hardware architecture, and comparable flexibility as that of software implementation.",
"author_names": [
"Pramod Govindan",
"Boyang Wang",
"Prashaanth Ravi",
"Jafar Saniie"
],
"corpus_id": 41520479,
"doc_id": "41520479",
"n_citations": 13,
"n_key_citations": 0,
"score": 0,
"title": "Hardware and software architectures for computationally efficient three dimensional ultrasonic data compression",
"venue": "IET Circuits Devices Syst.",
"year": 2016
},
{
"abstract": "Ultrasonic testing systems have been widely used in medical and industrial fields, demanding strict requirements for processing speed and re configurability of the hardware system. This paper presents a prototype of a reconfigurable, high performance, low cost and real time Ultrasonic Signal Acquisition and Processing (USAP) platform based on Zynq System on Chip (SoC) The USAP platform consists of five major components: Multi level voltage power supply; High voltage pulse generation; Ultrasonic signal acquisition; Sampling control unit and Digital signal processing module. The system uses Xilinx Zynq SoC as main processor and controller. It combines both ARM processor and field programmable gate array (FPGA) on the same chip, which makes the system capable of doing complex system configuration and performing high speed data processing. With this arrangement, the developed system is highly reconfigurable, where software and hardware configuration can be changed on both ARM and FPGA. This paper presents a system design flow of a complete ultrasonic testing system which is capable of acquiring ultrasonic data and performing advanced signal processing algorithms in real time.",
"author_names": [
"Boyang Wang",
"Jafar Saniie"
],
"corpus_id": 6179246,
"doc_id": "6179246",
"n_citations": 11,
"n_key_citations": 0,
"score": 0,
"title": "Ultrasonic Signal Acquisition and Processing platform based on Zynq SoC",
"venue": "2016 IEEE International Conference on Electro Information Technology (EIT)",
"year": 2016
},
{
"abstract": "Image Processing architecture and algorithms are used for the purpose of improving the image quality and to extract complete information in more precise manner. The need to process in real time has led to implement them on the target device with real time constraints like power and area. To implement image processing algorithms and architecture with the help of high level languages needs more blocks of code apart from inefficient in terms of time constraint. The easiest way to deal with facilitating usage of Xilinx System Generator/XSG blocks, XSG is a tool where we can build our design using pre existing block level components which are captured by using Xilinx block set from library environment and implement as per user requirement. The main responsibility of system generator is Xilinx block sets that provides the package integration with MATLAB Simulink and helps in co simulating FPGA hardware module. As per part application category, edge detection is a major essential application in medical field for proper diagnosis and correct treatments. Field Programmable Gate Arrays (FPGAs) have become more popular computing platforms as target device for digital signal processing. The Zynq System on Chip (SOC) is a dual processor platform with shared memory. This paper describes a fast architecture implementation of Sobel edge detection using the Zynq as a reconfigurable device. Our implementation is to merge both software and hardware using the Vivado and Zynq (SoC) As a result, our implementation is fast in terms of performance compare to the pre existing models. We make a comparison with other conventional edge detection techniques and show that the speed of operation of this design is much faster. This approach is tested over hardware or different gradient test vectors. Finally the algorithms are evaluated for the major essential images from the medical field to extract lasting effect in detecting the edges using gradient factor. The area and power factors are evaluated for reconfigurable hardware i.e, Zynq FPGA.",
"author_names": [
"Chiranjeevi Gubbi Narasimhamurthy",
"Subhash Kulkarni"
],
"corpus_id": 234923109,
"doc_id": "234923109",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Fast Architecture for Low Level Vision and Image Enhancement for Reconfigurable Platform",
"venue": "2021 International Conference on Advances in Electrical, Computing, Communication and Sustainable Technologies (ICAECT)",
"year": 2021
},
{
"abstract": "Invited Keynote. The Rising Wave of Field Programmability. Tightly Integrated Design Space Exploration with Spatial and Temporal Partitioning in SPARCS. Network Processors. A Dynamically Reconfigurable FPGA Based Content Addressable Memory for Internet Protocol Characterization. A Compiler Directed Approach to Hiding Configuration Latency in Chameleon Processors. Reconfigurable Network Processors Based on Field Programmable System Level Integrated Circuits. Internet Connected FPL. Prototyping. Field Programmable Communication Emulation and Optimization for Embedded System Design. FPGA Based Emulation: Industrial and Custom Prototyping Solutions. FPGA Based Prototyping for Product Definition. Implementation of Virtual Circuits by Means of the FIPSOC Devices. Dynamically Reconfigurable I. Static and Dynamic Reconfigurable Designs for a 2D Shape Adaptive DCT. A Self Reconfigurable Gate Array Architecture. Multitasking on FPGA Coprocessors. Design Visualisation for Dynamically Reconfigurable Systems. Verification of Dynamically Reconfigurable Logic. Miscellaneous I. Design of a Fault Tolerant FPGA. Real Time Face Detection on a Configurable Hardware System. Multifunctional Programmable Single Board CAN Monitoring Module. Self Testing of Linear Segments in User Programmed FPGAs. Implementing a Fieldbus Interface Using an FPGA. Technology Mapping and Routing Placement. Area Optimized Technology Mapping for Hybrid FPGAs. CoMGen: Direct Mapping of Arbitrary Components into LUT Based FPGAs. Efficient Embedding of Partitioned Circuits onto Multi FPGA Boards. A Placement Algorithm for FPGA Designs with Multiple I/O Standards. A Mapping Methodology for Code Trees onto LUT Based FPGAs. Biologically Inspired Methods. Possibilities and Limitations of Applying Evolvable Hardware to Real World Applications. A Co processor System with a Virtex FPGA for Evolutionary Computation. System Design with Genetic Algorithms. Implementing Kak Neural Networks on a Reconfigurable Computing Platform. Compact Spiking Neural Network Implementation in FPGA. Invited Keynote. Silicon Platforms for the Next Generation Wireless Systems What Role Does Reconfigurable Hardware Play? Invited Papers. From Reconfigurability to Evolution in Construction Systems: Spanning the Electronic, Microfluidic and Biomolecular Domains. A Specific Test Methodology for Symmetric SRAM Based FPGAs. Mobile Communication. DReAM: A Dynamically Reconfigurable Architecture for Future Mobile Communication Applications. Fast Carrier and Phase Synchronization Units for Digital Receivers Based on Re configurable Logic. Software Radio Reconfigurable Hardware System (SHaRe) Analysis of RNS FPL Synergy for High Throughput DSP Applications: Discrete Wavelet Transform. Dynamically Reconfigurable II. Partial Run Time Reconfiguration Using JRTR. A Combined Approach to High Level Synthesis for Dynamically Reconfigurable Systems. A Hybrid Prototyping Platform for Dynamically Reconfigurable Designs. Task Rearrangement on Partially Reconfigurable FPGAs with Restricted Buffer. Design Space Exploration. Generation of Design Suggestions for Coarse Grain Reconfigurable Architectures. Mapping of DSP Algorithms on Field Programmable Function Arrays. On Availability of Bit Narrow Operations in General Purpose Applications. A Comparison of FPGA Implementations of Bit Level and Word Level Matrix Multipliers. A New Floorplanning Method for FPGA Architectural Research. Miscellaneous II. Efficient Self Reconfigurable Implementations Using On chip Memory. Design and Implementation of an XC6216 FPGA Model in Verilog. Reusable DSP Functions in FPGAs. A Parallel Pipelined SAT Solver for FPGA's. A Multi node Dynamic Reconfigurable Computing System with Distributed Reconfiguration Controller. Applications I. A Reconfigurable Stochastic Model Simulator for Analysis of Parallel Systems. A CORDIC Arctangent FPGA Implementation for a High Speed 3D Camera System. Reconfigurable Computing for Speech Recognition: Preliminary Findings. Security Upgrade of Existing ISDN Devices by Using Reconfigurable Logic. The Fastest Multiplier on FPGAs with Redundant Binary Representation. Optimization. High Level Area and Performance Estimation of Hardware Building Blocks on FPGAs. Balancing Logic Utilization and Area Efficiency in FPGAs. Performance Penalty for Fault Tolerance in Roving STARs. Optimum Functional Decomposition for LUT Based FPGA Synthesis. Optimization of Run Time Reconfigurable Embedded Systems. Invited Keynote. It's FPL, Jim But Not as We Know It! Opportunities for the New Commercial Architectures. Invited Paper. Reconfigurable Systems: New Activities in Asia. StReAm: Object Oriented Programming of Stream Architectures Using PAM Blox. Architectures. Stream Computations Organized for Reconfigurable Execution (SCORE) Memory Access Schemes for Configurable Processors. Generating Addresses for Multi dimensional Array Access in FPGA On chip Memory. Combining Serialisation and Reconfiguration for FPGA Designs. Methodology and Technology. Multiple Wordlength Resource Binding. Automatic Temporal Floorplanning with Guaranteed Solution Feasibility. A Threshold Logic Based Reconfigurable Logic Element with a New Programming Technology. Exploiting Reconfigurability for Effective Detection of Delay Faults in LUT Based FPGAs. Compilation and Related Issues. Dataflow Partitioning and Scheduling Algorithms for WASMII, a Virtual Hardware. Compiling Applications for ConCISe: An Example of Automatic HW/SW Partitioning and Synthesis. Behavioural Language Compilation with Virtual Hardware Management. Synthesis and Implementation of RAM Based Finite State Machines in FPGAs. Applications II. Evaluation of Accelerator Designs for Subgraph Isomorphism Problem. The Implementation of Synchronous Dataflow Graphs Using Reconfigurable Hardware. Multiplexer Based Reconfiguration for Virtex Multipliers. Efficient Building of Word Recognizer in FPGAs for Term Document Matrices Construction. Short Papers. Reconfigurable Computing between Classifications and Metrics The Approach of Space/Time Scheduling. FPGA Implementation of a Prototype WDM On Line Scheduler. An FPGA Based Scheduling Coprocessor for Dynamic Priority Scheduling in Hard Real Time Systems. Formal Verification of a Reconfigurable Microprocessor. The Role of the Embedded Memories in the Implementation of Artificial Neural Networks. Programmable System Level Integration Brings System on Chip Design to the Desktop. On Applying Software Development Best Practice to FPGAs in Safety Critical Systems. Pre route Assistant: A Routing Tool for Run Time Reconfiguration. High Speed Computation of Lattice Gas Automata with FPGA. An Implementation of Longest Prefix Matching for IP Router on Plastic Cell Architecture. FPGA Implementation of an Extended Binary GCD Algorithm for Systolic Reduction of Rational Numbers. Toward Uniform Approach to Design of Evolvable Hardware Based Systems. Educational Programmable Hardware Prototyping and Verification System. A Stream Processor Architecture Based on the Con.gurable CEPRA S. An Innovative Approach to Couple EDA Tools with Recon.gurable Hardware. FPL Curriculum at Tallinn Technical University. The Modular Architecture of SYNTHUP, FPGA Based PCI Board for Real Time Sound Synthesis and Digital Signal Processing. A Rapid Prototyping Environment for Microprocessor Based System on Chips and Its Application to the Development of a Network Processor. Configuration Prefetching for Non deterministic Event Driven Multi context Schedulers. Wireless Base Station Design Using a Reconfigurable Communications Processor. Placement of Linear Arrays.",
"author_names": [
"Reiner W Hartenstein",
"Herbert Grunbacher"
],
"corpus_id": 12168904,
"doc_id": "12168904",
"n_citations": 30,
"n_key_citations": 1,
"score": 0,
"title": "Field Programmable Logic and Applications: The Roadmap to Reconfigurable Computing",
"venue": "Lecture Notes in Computer Science",
"year": 2002
}
] |
Silicon carbide benefits and advantages for power electronics circuits and systems | [
{
"abstract": "Silicon offers multiple advantages to power circuit designers, but at the same time suffers from limitations that are inherent to silicon material properties, such as low bandgap energy, low thermal conductivity, and switching frequency limitations. Wide bandgap semiconductors, such as silicon carbide (SiC) and gallium nitride (GaN) provide larger bandgaps, higher breakdown electric field, and higher thermal conductivity. Power semiconductor devices made with SiC and GaN are capable of higher blocking voltages, higher switching frequencies, and higher junction temperatures than silicon devices. SiC is by far the most advanced material and, hence, is the subject of attention from power electronics and systems designers. This paper looks at the benefits of using SiC in power electronics applications, reviews the current state of the art, and shows how SiC can be a strong and viable candidate for future power electronics and systems applications.",
"author_names": [
"Ahmed Elasser",
"T Paul Chow"
],
"corpus_id": 62292468,
"doc_id": "62292468",
"n_citations": 375,
"n_key_citations": 16,
"score": 1,
"title": "Silicon carbide benefits and advantages for power electronics circuits and systems",
"venue": "Proc. IEEE",
"year": 2002
},
{
"abstract": "The move towards smaller and more efficient power electronics devices has led to the introduction of wide band gap devices within the power electronics field. The fast switching characteristics of these devices that produce the advantages, also have an adverse impact: the harmonic content of these edges exacerbate the effects of parasitic inductance and capacitance in printed circuit boards, increase EMI and amplify transmission line effects. This paper investigates the use of wide band gap devices through the design and implementation of a silicon carbide (SiC) converter system in an electrical engineering final year capstone project, in which the deleterious effects of wide band gap devices are used as a learning tool. This allows students to consolidate, as well as extend, their electrical engineering knowledge and research skills. A case study is presented from a capstone project carried out at the University of Newcastle, Australia which highlights the benefits of using these devices as a learning tool.",
"author_names": [
"R L Sykes",
"Terrence J Summers",
"C Starkey"
],
"corpus_id": 218494103,
"doc_id": "218494103",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Silicon Carbide Converters as a Learning Tool for Final Year Engineering Students",
"venue": "2019 29th Australasian Universities Power Engineering Conference (AUPEC)",
"year": 2019
},
{
"abstract": "Power systems designed for use in NASA space missions are required to work reliably under harsh environment conditions. Radiation, thermal cycling, and extreme temperature exposures, which are typically encountered in almost all of the space exploration missions, are a major concern for the operation and reliability of on board electronics of the spacecraft power system. Besides reliability, efficiency constitutes another critical requirement in space applications where size and weight are of utmost importance. This, in turn, would require the use of high power, low loss devices and circuits capable of operation in space borne radiation and other environmental stresses. Today's electronics based on silicon technology would not be able to meet the stringent requirements of space systems without the use of the present day conventional radiation shielding structures and thermal control elements for proper operation. Semiconductor devices based on wide bandgap materials, especially silicon carbide (SiC) are becoming more readily available as the enabling technologies begin to mature. The wide bandgap structure of SiC based power devices offers great benefits when compared with those made of silicon (Si) Some of these advantages include high breakdown voltage, higher power and current densities, low on resistance, higher switching frequency, and high operating temperatures. Table I lists a comparison of properties of silicon and silicon carbide semiconductor materials [1] By being able to withstand large voltages with small leakage currents and fast switching speeds, SiC devices show great promise and become good candidates for use in future power electronic systems. The low on resistance of wide band gap materials allows the development of a new generation of transistor devices that switch faster and with greatly reduced losses. The combined higher switching speed and efficiency of these transistors, for example, allows the operation of DC/DC converters at very high frequencies, thereby reducing weight, saving board space, and conserving power. Information pertaining to performance of these new wide bandgap devices in the space environment is very scarce. Such data is very critical so that proper design is implemented in order to ensure mission success and to mitigate risks associated with exposure of on board systems to the space operational environment. In this work, samples of an N channel enhancement mode metal oxide semiconductor field effect transistor (MOSFET) based on SiC technology were exposed to radiation followed by long term thermal cycling over a wide temperature range to determine their susceptibility and to address their reliability for use in space applications. The results of this experimental work are presented and discussed. This report must be viewed in COLOR.",
"author_names": [
"Richard L Patterson",
"Robert J Scheidegger",
"Jean-Marie Lauenstein",
"Megan C Casey",
"Leif Scheick",
"Ahmad Hammoud"
],
"corpus_id": 106589071,
"doc_id": "106589071",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Impact of Total Ionizing Dose Radiation Testing and Long Term Thermal Cycling on the Operation of CMF20120D Silicon Carbide Power MOSFET",
"venue": "",
"year": 2013
},
{
"abstract": "With an ever industrializing world, electrical power is a valuable commodity that is increasing in worth. As electricity is passed from the source of generation to the end users, it changes magnitude and often frequency, to optimize the delivery process. Power electronics play a crucial role in this effort. Since its inception in the 1950's, power electronic have relied on switchings devices created from silicon (Si) During this time, manufacturing capabilities have perfected to the point that the atomic properties of Si are quickly becoming a bottleneck to further progress in this field. Engineers would like devices that can sustain higher voltages, realize better efficiency, switch at faster speeds, and operate at higher temperatures. For these reasons and others, researchers are evaluating power devices created from wide bandgap (WBG) semiconductors. Two of these materials, silicon carbide (SiC) and gallium nitride (GaN) are already being offered commercially. In terms of power device functionality, these components switch at higher speeds and with a lower on resistance. Demonstrations of devices with breakdown voltages higher than their Si counterparts have already begun to appear. Operating at higher temperature is also possible with these new devices, however progress is moving slower in this area due to issues with packaging and auxiliary hardware. With all of these strengths, these components are not without some limitations. ii Switched capacitor (SC) circuits have been utilized in low power applications due in part to their ability to realize higher power density. In higher power applications, these circuits do have issues with voltage regulation and electromagnetic interference (EMI) However, as the following dissertation demonstrates, SC circuits are ideally suited for WBG power devices. As part of this effort, a modular SC platform was built to evaluate 200 V GaN devices. Through utilizing soft switching techniques, high efficiency was obtained for a voltage doubler operating at 500 W utilizing a switching frequency of 383 kHz and 893 kHz. Next, several modules were cascaded together to create a stand alone voltage doubler that is capable of converting 30 VDC into 120 VAC The benefits of a SC inverter were studied at voltage and power levels consistent with motor drives and grid tied inverters. A potential replacement for the traditional power electronic systems in a hybrid electric vehicle (HEV) was evaluated. Preliminary test results are shown for tests at 400 V and 5 kW. SC circuits have the unique ability to create circuits with multiple ports. One contribution of this work is a pulse width modulation (PWM) strategy for SC inverters that produces two AC ports utilizing a single DC port. The control strategy for this is presented in the following work along with supporting analysis and experimental results. Finally, a future application for high voltage, high current devices inside of fusion energy power supply systems was explored. This study demonstrates that significant advantages can be accrued using existing devices in these power systems. The case study for this investigation was the vertical stability coil power supply system and the",
"author_names": [
"Mark J Scott"
],
"corpus_id": 114855070,
"doc_id": "114855070",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Applications, Benefits, and Challenges of Wide Bandgap Based Power Inversion",
"venue": "",
"year": 2015
},
{
"abstract": "Silicon carbide (SiC) based semiconductor electronic devices and circuits are presently being developed for use in high temperature, high power, and high radiation conditions under which conventional semiconductors cannot adequately perform. Silicon carbide's ability to function under such extreme conditions is expected to enable significant improvements to a far ranging variety of applications and systems. These range from greatly improved high voltage switching for energy savings in public electric power distribution and electric motor drives to more powerful microwave electronics for radar and communications to sensors and controls for cleaner burning more fuel efficient jet aircraft and automobile engines [1 7] In the particular area of power devices, theoretical appraisals have indicated that SiC power MOSFET's and diode rectifiers would operate over higher voltage and temperature ranges, have superior switching characteristics, and yet have die sizes nearly 20 times smaller than correspondingly rated silicon based devices [8] However, these tremendous theoretical advantages have yet to be widely realized in commercially available SiC devices, primarily owing to the fact that SiC's relatively immature crystal growth and device fabrication technologies are not yet sufficiently developed to the degree required for reliable incorporation into most electronic systems. This chapter briefly surveys the SiC semiconductor electronics technology. In particular, the differences (both good and bad) between SiC electronics technology and the well known silicon VLSI technology are highlighted. Projected performance benefits of SiC electronics are highlighted for several large scale applications. Key crystal growth and device fabrication issues that presently limit the performance and capability of high temperature and high power SiC electronics are identified.",
"author_names": [
"Philip G Neudeck"
],
"corpus_id": 52997177,
"doc_id": "52997177",
"n_citations": 33,
"n_key_citations": 5,
"score": 0,
"title": "Silicon Carbide Technology",
"venue": "",
"year": 2006
},
{
"abstract": "Electricity generation currently accounts for 40% of primary energy consumption in the U.S. and over the next 25 years is projected to increase more than 50% worldwide. Electricity continues to be the fastest growing form of end use energy. Power electronics are responsible for controlling and converting electrical power to provide optimal conditions for transmission, distribution, and load side consumption. Estimates suggest that the fraction of electricity processed through power electronics could be as high as 80% in the US by 2030 (including generation and consumption) approximately a twofold increase over the current proportion. The U.S. Department of Energy's Advanced Research Project Agency for Energy (ARPA E) was established in 2009 to fund creative, out of the box, transformational energy technologies that are too early for private sector investment, at make or break points in their technology development cycle. ARPA E's investment portfolio aims to generate options to address specific energy challenges that could provide dramatic benefits for the nation. Development of advanced power electronics with unprecedented functionality, efficiency, reliability, and reduced form factor will provide the U.S. a critical technological advantage in an increasingly electrified world economy. Fast switching power semiconductor devices are the key to increasing the efficiency and reducing the size of power electronic systems. Recent advances in wide band gap semiconductor materials, such as silicon carbide (SiC) and gallium nitride (GaN) are enabling a new generation of power semiconductor devices that far exceed the performance of silicon based devices. Past ARPA E programs (ADEPT, Solar ADEPT, SWITCHES) have focused on challenges associated with fabricating WBG high performance switching devices. Program developments led to a new generation of devices that operate at much higher powers, voltages, frequencies, and temperatures than traditional silicon based semiconductor devices. Two most recent programs recently launched by ARPA E in the area of power electronics are CIRCUITS and PNDIODES. The projects that comprise ARPA E's CIRCUITS (Creating Innovative and Reliable Circuits Using Inventive Topologies and Semiconductors) program seek to accelerate the development and deployment of a new class of efficient, lightweight, and reliable power converters, based on wide bandgap (WBG) semiconductors. CIRCUITS projects build on the earlier ARPA E programs by designing circuit topologies and building blocks optimally suited for WBG attributes to maximize overall electrical system performance and reliability. In addition, a reduced form factor (size and weight) will drive adoption of higher performance and more efficient power converters relative to today's state of the art systems. Innovations stemming from CIRCUITS projects have the potential to affect high impact applications wherever electrical power is generated or used, including the electric grid, industrial motor controllers, automotive electrification, heating, ventilation, air conditioning, solar and wind power systems, datacenters, aerospace control surfaces, wireless power transfer, and consumer electronics. PNDIODES (Power Nitride Doping Innovation Offers Devices Enabling SWITCHES) funds transformational advances and mechanistic understanding in the process of selective area doping in the III Nitride wide band gap (WBG) semiconductor material system and the demonstration of arbitrarily placed, reliable, contactable, and generally useable p n junction regions that enable high performance and reliable vertical power electronic semiconductor devices. The microscopic mechanistic understanding and transformational technologies will address the major obstacle in the fabrication of vertical GaN power electronic devices.",
"author_names": [
"Isik C Kizilyalli",
"Yanzhi Xu",
"Eric P Carlson",
"Joseph S Manser",
"Daniel W Cunningham"
],
"corpus_id": 220360868,
"doc_id": "220360868",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Keynotes: \"Current and future directions in power electronic devices and circuits based on wide band gap semiconductors\"",
"venue": "",
"year": 2017
},
{
"abstract": "Silicon carbide (SiC) is a very promising semiconductor material for the development of electronics that will operate at high temperature; it has the additional advantage that for some applications it should be less sensitive to radiation than Si or GaAs. There will be advantages to eventually using SiC to build very radiation resistant, high temperature circuits, which could be located near or within severe radiation environments. System benefits would come from development of circuits with sensor amplifier/multiplexer and control signal demultiplexer/motor drive electronics functions. The goal of our research is ultimately to demonstrate that high temperature radiation hardened circuits can be built to meet the kinds of needs discussed above, In this paper we report on the operation of state of the art SiC JFETs over a wide temperature range and in severe radiation environments. These devices represent the current state of the art but do not represent the limits of operation of SiC semiconductor devices. This work was in fact carried out to increase our understanding of the device characteristics so as to allow the design of new SiC circuits which could meet the extremely stressful requirements of nuclear power systems.",
"author_names": [
"James McGarrity",
"Charles J Scozzie",
"James C Blackburn",
"W M Delancy"
],
"corpus_id": 60597848,
"doc_id": "60597848",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "High temperature silicon carbide FETs for radiation environments",
"venue": "1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record",
"year": 1995
},
{
"abstract": "Inductive power transfer (IPT) is widely discussed as an alternative to contact charger for plug in hybrid and electric vehicles. This paper analyzes a contactless battery charger back end power factor correction (PFC) concept, reducing the primary side circuit complexity and physical size. For that purpose, the main volume and loss factors of a contactless battery charger are identified, discussing the partitioning of tasks to perform a unity power factor operation. An analysis of the most commonly used front end PFC and the proposed back end PFC configuration is performed, with the aim of highlighting benefits and limitations of each variant. Moreover, performance of silicon (Si) and gallium nitride (GaN) devices has also been evaluated, defining the main advantages and drawbacks of both semiconductor technologies in different IPT scenarios. The study is verified experimentally on a 3.2 kW contactless battery charger.",
"author_names": [
"Ander Avila",
"Asier Garcia-Bediaga",
"Ugaitz Iruretagoyena",
"Irma Villar",
"Alejandro Rujas"
],
"corpus_id": 52301492,
"doc_id": "52301492",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Comparative Evaluation of Front and Back End PFC IPT Systems for a Contactless Battery Charger",
"venue": "IEEE Transactions on Industry Applications",
"year": 2018
},
{
"abstract": "Inductive power transfer (IPT) is widely discussed as an alternative to contact charger for plug in hybrid and electric vehicles (PHEV/EV) This paper analyzes a contactless battery charger back end power factor correction (PFC) concept, which allows to reduce the primary side circuit complexity and physical size. For that purpose, the main volume and loss factors of a contactless battery charger are identified, discussing the partitioning of tasks to perform a unity power factor operation. An analysis of the most commonly used front end PFC and the proposed back end PFC configuration is performed, with the aim to highlight benefits and limitations of each variant. Moreover, Silicon (Si) and Gallium Nitride (GaN) devices performance has been also evaluated, defining the main advantages and drawbacks of different semiconductor technologies in this application. The considerations are verified experimentally on a 3.2 kW contactless battery charger.",
"author_names": [
"Ander Avila",
"Asier Garcia-Bediaga",
"Ugaitz Iruretagoyen",
"Irma Villar",
"Alejandro Rujas"
],
"corpus_id": 36045587,
"doc_id": "36045587",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Comparative evaluation of front and back end PFC IPT systems for a contactless battery charger",
"venue": "2017 IEEE Energy Conversion Congress and Exposition (ECCE)",
"year": 2017
},
{
"abstract": "The superior properties of silicon carbide (SiC) power electronic devices compared with silicon (Si) are expected to have a significant impact on next generation vehicles, especially hybrid electric vehicles (HEVs) The system level benefits of using SiC devices in HEVs include a large reduction in the size, weight, and cost of the power conditioning and/or thermal systems. However, the expected performance characteristics of the various semiconductor devices and the impact that these devices could have in applications are not well understood. Simulation tools have been developed and are demonstrated for SiC devices in relevant transportation applications. These tools have been verified by experimental analysis of SiC diodes and MOSFETs and can be used to assess the impact of expected performance gains in SiC devices and determine areas of greatest impact in HEV systems. INTRODUCTION Presently, almost all of the power electronics converter systems in automotive applications use silicon(Si based power semiconductor switches. The performance of these systems is approaching the theoretical limits of the Si fundamental material properties. The emergence of silicon carbide(SiC based power semiconductor switches likely will result in substantial improvements in the performance of power electronics converter systems in transportation applications. SiC is a wide bandgap semiconductor, and SiC based power switches can be used in electric traction drives and other automotive electrical subsystems with many benefits compared with Si based switches. In this paper, experimental characteristics of Si and SiC are used to develop a simulation model for SiC power electronics devices. The main objective of developing these simulation tools is to show some of the systemlevel benefits of using SiC devices in HEVs such as the large reduction in the size, weight, and cost of the power conditioning and/or thermal management systems. Temperature dependent circuit models for SiC diodes and MOSFETs have been developed. Power losses and device temperatures have been computed for a traction drive in HEVs. Temperature and efficiency profiles have been created for the devices for powering a vehicle over an urban driving cycle. The system benefits in using SiC devices are highlighted through simulation and experimental results. At Oak Ridge National Laboratory (ORNL) a SiC power MOSFET is presently being designed. This power device will be used in power electronics converter systems for automotive applications to demonstrate the benefits of SiC based power devices. One of the selected automotive applications for this project is a traction drive. New gate drive layouts, circuit topologies, and filter requirements will also be developed to take advantage of the special properties of SiC devices. ADVANTAGES OF SiC COMPARED WITH Si As mentioned earlier, SiC is a wide bandgap semiconductor, and this property of SiC is expected to yield greatly superior power electronics devices once processing and fabrication issues with this material are solved. Some of the advantages of SiC compared with Si based power devices are as follows: 1. SiC based power devices have higher breakdown voltages (5 to 30 times higher than those of Si) because of their higher electric breakdown field. 2. SiC devices are thinner, and they have lower onresistances. The substantially higher breakdownvoltage for SiC allows higher concentrations of doping and consequently a lower series resistance. For lowbreakdown voltage devices ~50V) SiC unipolar device on resistances are around 100 times less; and at higher breakdown voltages ~5000V) they are up __________________________________________________ *Prepared by the Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, managed by UT Battelle for the U.S. Department of Energy under contract DE AC05 00OR22725. The submitted manuscript has been authored by a contractor of the U.S. Government under Contract No. DE AC0500OR22725. Accordingly, the U.S. Government retains a nonexclusive, royalty free license to publish from the contribution, or allow others to do so, for U.S. Government purposes. to 300 times less [1] With lower Ron, SiC unipolar power devices have lower conduction losses (Figure 1) and therefore higher overall efficiency. 3. SiC has a higher thermal conductivity and thus a lower junction to case thermal resistance, Rth jc. This means heat is more easily conducted away from the device junction, and thus the device temperature increase is slower. 4. SiC can operate at high temperatures because of its wider bandgap. SiC device operation at up to 600degC is mentioned in the literature [2] Most Si devices, on the other hand, can operate at a maximum junction temperature of only 150degC. 5. Forward and reverse characteristics of SiC power devices vary only slightly with temperature and time; therefore, SiC devices are more reliable. 6. SiC based devices have excellent reverse recovery characteristics [3] With less reverse recovery current, the switching losses and electromagnetic interference (EMI) are reduced and there is less or no need for snubbers. Typical turn off waveforms of commercial Si and SiC diodes are given in Figure 2. 7. SiC is extremely radiation hard; i.e. radiation does not degrade the electronic properties of SiC. MACHINE AND INVERTER MODELING System level simulation tools have been developed to calculate the conduction and switching losses of the power devices in an inverter used as a motor drive in an HEV. The efficiency of the inverter can then be determined from these losses. The simulation tool is also able to estimate the junction temperature of the power semiconductor devices and recommend an appropriate heatsink size. In this paper, an averaging technique [4] is used to model the power electronics switching losses in an HEV traction drive system. The models are compatible with the Department of Energy's ADvanced VehIcle SimulatOR (ADVISOR) models. The developed system models use torque and speed values from the ADVISOR simulation to determine the current profile of the system over the Federal Urban Driving Schedule (FUDS) Circuit level simulation is not practical for this work because the device variables are in microor nanoseconds and the system variables are in 1 second increments. Figure 3 shows the block diagram of the system modeling approach, and Figure 4 shows the three phase inverter and induction machine for the traction drive system. 300 320 340 360 380 400 420 440 460 480 500 0.01 1",
"author_names": [
"Leon M Tolbert",
"Burak Ozpineci",
"Syed Kamrul Islam",
"Fang Zheng Peng"
],
"corpus_id": 19405134,
"doc_id": "19405134",
"n_citations": 50,
"n_key_citations": 1,
"score": 0,
"title": "Impact of SiC Power Electronic Devices for Hybrid Electric Vehicles",
"venue": "",
"year": 2002
}
] |
SET/CMOS universal literal gate-based Analog-to-Digital converter. | [
{
"abstract": "In this paper, we propose an analog to digital converter (ADC) using a hybrid single electron transistor/complementary metal oxide semiconductor (SET/CMOS) universal literal gate based on the Coulomb oscillation phenomenon of a SET. The SET/CMOS universal literal gate consists of the SET/resistor inverter and the CMOS inverter, whose input is connected to the output of SET/resistor inverter. Because the CMOS inverter has the high input impedance and the low output impedance, the proposed circuit makes it possible to overcome the disadvantage of the high output impedance of a SET/resistor inverter by connecting its output to any input of CMOS circuit. The circuit has shown high immunity on temperature and can eliminate the background charge effect as applied to ADC. Using SPICE macromodel of SET at 30 K, we demonstrated the performance of a 4 bit ADC, composed of SET/CMOS universal literal gate and capacitive divider. These results can be simply extended to multi bit ADC.",
"author_names": [
"Myung-Jo Chun",
"Yoon-Ha Jeong"
],
"corpus_id": 107192923,
"doc_id": "107192923",
"n_citations": 4,
"n_key_citations": 2,
"score": 1,
"title": "SET/CMOS universal literal gate based analog to digital converter",
"venue": "2003 Third IEEE Conference on Nanotechnology, 2003. IEEE NANO 2003.",
"year": 2003
},
{
"abstract": "We propose a novel analog/digital (A/D) converter based on single electron transistors (SETs) in this paper. In the proposed A/D converter, the core cell is a SET module, composed of capacitive dividers and SET based universal literal gates. The SET based universal literal gate is similar to the well known Tucker's inverter (J.R. Tucker, J. Appl. Phys. vol. 72, no. 9, pp. 4399 4413, 1992) but here it acts as digital conversion and the inputs of upper SET and lower SET are two opposite voltages. In the SET based universal literal gate, by adjusting the some parameters, the output having about 50% duty ratio of square wave like and zero output for zero input (in contrast, high voltage output for zero input in Tucker's inverter) is obtained, where we fully utilize the periodic oscillation of SETs on gate voltage /spl I.bar/V/sub G/=e/C/sub G/ We demonstrate the basic function of a 4 bit SET based A/D converter using the MOSES program developed by K.K. Likharev's group, which is based on the so called orthodox theory and Monte Carlo method. The results may be easily extended to higher bit A/D converters.",
"author_names": [
"Chaohong Hu",
"J F Jiang",
"Q Y Cai"
],
"corpus_id": 110774053,
"doc_id": "110774053",
"n_citations": 18,
"n_key_citations": 1,
"score": 0,
"title": "A single electron transistor based analog/digital converter",
"venue": "Proceedings of the 2nd IEEE Conference on Nanotechnology",
"year": 2002
},
{
"abstract": "Analog circuits and systems research and education can benefit from the flexibility provided by large scale Field Programmable Analog Arrays (FPAAs) This demonstration will present visitors with the hardware and software infrastructure supporting the use of a family of floating gate based FPAAs being developed at Georgia Tech [1] A picture of the programming and control hardware that will be demonstrated is found in Figure la. Figure lb shows the software flow that will be demonstrated [2] The infrastructure is compact and portable and provides the user with a comprehensive set of tools for custom analog circuit design and implementation. The infrastructure includes the FPAA integrated circuit (IC) discrete analog to digital converters (ADC) digital to analog converters (DAC) and amplifier ICs; a 32 Bit ARM based microcontroller (mC) for interfacing the FPAA with a laptop computer; and Matlab and targeting software. The FPAA hardware communicates with Matlab over a Universal Serial Bus (USB) connection. The USB connection also provides the hardware's power. The software tools in the demonstration include three major systems: a Matlab Simulink FPAA program, a SPICE to FPAA compiler called GRASPER, and a visualization tool called RAT. Figure 2 shows a block diagram of the Programming and Control board and demonstration setup.",
"author_names": [
"Scott Koziol",
"Craig Schlottmann",
"Arindam Basu",
"Stephen Brink",
"Csaba Petre",
"Brian P Degnan",
"Shubha Ramakrishnan",
"Paul E Hasler",
"Aurele Balavoine"
],
"corpus_id": 1093836,
"doc_id": "1093836",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Live demonstration: Hardware and software infrastructure for a family of floating gate based FPAAs",
"venue": "Proceedings of 2010 IEEE International Symposium on Circuits and Systems",
"year": 2010
},
{
"abstract": "A new digital quantizer structure is proposed based on single electron box (SEB) The structure exploits SEB which constitutes the simplest single electron device with one capacitor and one tunnel junction. Specifically, the quantizer is composed of two SEB's and one differential amplifier. Since the order of tunnel junction and capacitor determines the output characteristics in the single electron box, the quantized signal is achieved by adjusting the value of capacitance. The usefulness of digital quantizer is demonstrated by implementing the 4 bit analog to digital converter (ADC) The ADC consists of the proposed quantizer block, capacitive divider and universal literal gate. The result shows almost no delay and good performance. The ADC with proposed digital quantizer docs not require latching blocks, rendering thereby the entire circuit much simpler. All the simulations have been performed with Monte Carlo based simulator called SIMON.",
"author_names": [
"Sung-Woo Jung",
"Bong-Hoon Lee",
"Yoon-Ha Jeong"
],
"corpus_id": 37290755,
"doc_id": "37290755",
"n_citations": 18,
"n_key_citations": 1,
"score": 0,
"title": "Digital quantizer based on single electron box for multi valued logic circuits",
"venue": "5th IEEE Conference on Nanotechnology, 2005.",
"year": 2005
},
{
"abstract": "Digital pulse processing has developed rapidly during recent years. Moreover, it has been widely applied in many fields. In this study, we introduce a digital pulse processing method for 2pa and 2pb emitter measurement. Our digital pulse processing method for 2pa and 2pb emitter measurement is comprised of a field programmable gate array based acquisition card and a pulse height analysis routine. We established two channels (one for the a emitter and one for the b emitter) on an acquisition board using an analog to digital converter with a 16 bit resolution at a speed of 100 million samples per second. In this study, we used captured and stored data to analyze emission rate counts and spectrums. The method we established takes into account noise cancelation, dead time correction, background subtraction, and zero energy extrapolation. We carefully designed control procedures in order to simplify pulse width fitting and threshold level setting. We transmitted data and commands through a universal serial bus between the acquisition board and the computer. The results of our tests prove that our method performs well in pulse reconstruction fidelity and amplitude measurement accuracy. Compared with the current standard method for measuring 2pa and 2pb emission rates, our system demonstrates excellent precision in emission rate counting.",
"author_names": [
"Zheng Tu",
"Ke-Zhu Song",
"Ming Zhang",
"Zhi-Jie Yang",
"Zhi-Guo Ding",
"Hongyan Yu",
"Juncheng Liang",
"Haoran Liu"
],
"corpus_id": 63556459,
"doc_id": "63556459",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "A new digital pulse processing method for 2pa and 2pb emitter measurement",
"venue": "",
"year": 2016
},
{
"abstract": "The invention discloses an FPGA (Field Programmable Gate Array) based high speed data acquisition system comprising a differential amplification unit for receiving a simulation signal, an A/D (Analog/Digital) conversion unit connected with the differential amplification unit, an FPGA processing unit connected with the A/D conversion unit and a microprocessor connected with the FPGA processing unit, wherein the microprocessor is connected with an upper computer through a communication interface. The FPGA based high speed data acquisition system disclosed by the invention has the characteristics of high sampling speed, high precision, high storage capacity, high uploading speed, and the like; parallel alternating real time sampling is used as a sampling mode; two A/D converters with the sampling speed of 125MSPS (Multiphase Serial Parallel Serial Storage) are adopted to sample one path of signal in an alternating and parallel way and realize the sampling speed of 250MSPS; and the sampling precision can reach 12bits and sampling points are 1 25K. The FPGA based high speed data acquisition system has a hardware cumulative function, the cumulative frequency of 1 250K and the bandwidth of 200MHz and supports USB (Universal Serial Bus) 2.0 full speed communication; the input range of signals is 2Vp p; and the FPGA based high speed data acquisition system can be widely applied to the fields of acquisition of multi path signals having higher requirement on the speed, the precision and the storage capacity of data acquisition.",
"author_names": [
""
],
"corpus_id": 140272283,
"doc_id": "140272283",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "FPGA (Field Programmable Gate Array) based high speed data acquisition system",
"venue": "",
"year": 2010
},
{
"abstract": "This paper presents a digital signal processing system specially designed for eddy currents non destructive testing. This new system has a field programmable gate array based processing core, communication interfaces, data conversion and analog devices to interface the probes. Communication with personal computers is ensured by Ethernet 10/100 and universal serial bus 2.0 high speed interfaces. The proposed architecture enables to set several combinations of peripherals cards to generate or acquire probe signals. Also, the new system allows the digital generation and analysis of the probe signals through multiple digital signal processing algorithms. Two different peripheral cards have been developed to meet the needs for the new IOnic concept of eddy currents probe. The IOnic acquisition card is composed by a programmable gain amplifier and a high speed analog to digital converter. The current stimulus generation is achieved with a digital to analog converter and a high output current transconductance amplifier. Together, the two peripherals are able to operate the probe from 10 kHz up to 10 MHz. An additional peripheral card to interface stepper motors was designed for sensor positioning.",
"author_names": [
"Luis Filipe Soldado Granadeiro Rosado",
"Moises Simoes Piedade",
"Pedro M Ramos",
"Telmo G Santos",
"Pedro Vilaca"
],
"corpus_id": 46146309,
"doc_id": "46146309",
"n_citations": 15,
"n_key_citations": 0,
"score": 0,
"title": "A reconfigurable digital signal processing system for eddy currents non destructive testing",
"venue": "2010 IEEE Instrumentation Measurement Technology Conference Proceedings",
"year": 2010
},
{
"abstract": "Devices that combine single electron and metal oxide semiconductor (MOS) transistors are newly proposed as basic components of multiple valued (MV) logic, such as a universal literal gate and a quantizer. We verified their operation using single electron and MOS transistors fabricated on the same wafer by pattern dependent oxidation of silicon. We also discuss their application to an analog to digital converter, a MV adder, and MV static random access memory.",
"author_names": [
"Hiroshi Inokawa",
"Akira Fujiwara",
"Yasuo Takahashi"
],
"corpus_id": 111118906,
"doc_id": "111118906",
"n_citations": 126,
"n_key_citations": 12,
"score": 0,
"title": "A multiple valued logic and memory with combined single electron and metal oxide semiconductor transistors",
"venue": "",
"year": 2003
},
{
"abstract": "This paper proposes smart universal multiple valued (MV) logic gates by transferring single electrons (SEs) The logic gates are based on mosfet based SE turnstiles that can accurately transfer SEs with high speed at high temperature. The number of electrons transferred per cycle by the SE turnstile is a quantized function of its gate voltage, and this characteristic is fully exploited to compactly finish MV logic operations. First, we build arbitrary MV literal gates by using pairs of SE turnstiles. Then, we propose universal MV logic to value conversion gates and MV analog digital conversion circuits. We propose a SPICE model to describe the behavior of the mosfet based SE turnstile. We simulate the performances of the proposed gates. The MV logic gates have small number of transistors and low power dissipations.",
"author_names": [
"Wancheng Zhang",
"Nan-Jian Wu"
],
"corpus_id": 26276748,
"doc_id": "26276748",
"n_citations": 9,
"n_key_citations": 2,
"score": 0,
"title": "Smart Universal Multiple Valued Logic Gates by Transferring Single Electrons",
"venue": "IEEE Transactions on Nanotechnology",
"year": 2008
},
{
"abstract": "Proposes merged single electron and MOS devices that serve as basic components of multiple valued logic, such as a universal literal gate and a quantizer. We verified their operation by using single electron transistors and MOSFETs fabricated on the same wafer by pattern dependent oxidation process. We also discuss their application to an analog to digital converter and a multiple valued adder.",
"author_names": [
"Hiroshi Inokawa",
"Akira Fujiwara",
"Y Takahashi"
],
"corpus_id": 1267795,
"doc_id": "1267795",
"n_citations": 66,
"n_key_citations": 3,
"score": 0,
"title": "A multiple valued logic with merged single electron and MOS transistors",
"venue": "International Electron Devices Meeting. Technical Digest (Cat. No.01CH37224)",
"year": 2001
}
] |
GaN on wafer formation semiconductor basics | [
{
"abstract": "The increasing demand for complementary metal oxide semiconductor integrated GaN based optoelectronics and power electronics calls for wafer scale crack free and high quality GaN thick film grown on Si. However, the huge mismatch in both lattice constant and coefficient of thermal expansion between GaN and Si often causes a high density of threading dislocations (TDD, typically 109 1010 cm 2) and the formation of micro crack networks, producing a poor quality GaN film with a limited thickness <6 um) By virtue of a well designed Al composition step graded AlN/AlGaN buffer, a wafer scale crack free 10 um thick successive GaN with a low TDD of 5.8 x 107 cm 2 grown on Si was achieved for the first time. Detailed study on the depth dependent strain and dislocation evolution shed light on the complex interplay between strain relaxation and defect reduction, as well as their influences on the GaN optical properties along the growth direction. This work paves the way for building high performance GaN based optoelectronics and power electronics on the Si platform.",
"author_names": [
"Jianxun Liu",
"Yin-Lin Huang",
"Xiujian Sun",
"Xiaoning Zhan",
"Qian Sun",
"Hongwei Gao",
"Meixin Feng",
"Yu Zhou",
"Masao Ikeda",
"Honbo Yang"
],
"corpus_id": 199678450,
"doc_id": "199678450",
"n_citations": 7,
"n_key_citations": 0,
"score": 1,
"title": "Wafer scale crack free 10 um thick GaN with a dislocation density of 5.8 x 107 cm 2 grown on Si",
"venue": "Journal of Physics D: Applied Physics",
"year": 2019
},
{
"abstract": "Al x In y Ga 1 x y N GaN heterostructures were grown on 4 in. p type Si wafers to investigate the effect of In composition in the quaternary nitride layer on the electrical performance of Al 2 O 3 AlInGaN GaN based normally ON metal insulator semiconductor high electron mobility transistors (MIS HEMTs) From the comparative study of the electrical measurements, it was observed that the transport properties of the devices were relatively poor in the presence of higher In composition in the quaternary N layer. The deterioration of the electrical characteristics of MIS HEMTs originated from the formation of deep pits on the AlInGaN epilayer surface caused by the segregation of In atoms during epitaxial growth. However, the formation of such pits was reduced for the quaternary epilayer with lower In content and exhibited better transport performance. A maximum current density I d m a x) of 780 mA/mm with a specific ON resistance of 0.71 m O cm 2 was observed for the device fabricated on the wafer with an In composition of 9% in the AlInGaN epilayer. We have achieved a high breakdown voltage of 793 V with a device with the gate to drain distance L g d) of 20 m m under the off state condition. Al x In y Ga 1 x y N GaN heterostructures were grown on 4 in. p type Si wafers to investigate the effect of In composition in the quaternary nitride layer on the electrical performance of Al 2 O 3 AlInGaN GaN based normally ON metal insulator semiconductor high electron mobility transistors (MIS HEMTs) From the comparative study of the electrical measurements, it was observed that the transport properties of the devices were relatively poor in the presence of higher In composition in the quaternary N layer. The deterioration of the electrical characteristics of MIS HEMTs originated from the formation of deep pits on the AlInGaN epilayer surface caused by the segregation of In atoms during epitaxial growth. However, the formation of such pits was reduced for the quaternary epilayer with lower In content and exhibited better transport performance. A maximum current density I d m a x) of 780 mA/mm with a specific ON resistance of 0.71 m O cm 2 was observed fo.",
"author_names": [
"Debaleen Biswas",
"Hirotaka Fujita",
"Naoki Torii",
"Takashi Egawa"
],
"corpus_id": 197518614,
"doc_id": "197518614",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Effect of In composition on electrical performance of AlInGaN/GaN based metal insulator semiconductor high electron mobility transistors (MIS HEMTs) on Si",
"venue": "Journal of Applied Physics",
"year": 2019
},
{
"abstract": "The feasibility of van der Waals (VdW) heteroepitaxy of molybdenum disulphide (MoS2) layers on gallium nitride (GaN) semiconductor has attracted significant interest in heterojunction optoelectronic device applications. Here, we report on the growth of uniform MoS2 layers on free standing GaN semiconductor for vertical heterojunction device application. A uniform MoS2 layer was directly grown on the n type GaN wafer by sulphurization process of molybdenum oxide thin layer. Raman and scanning electron microscopy (SEM) analyses showed homogenous growth of the few layers MoS2 forming a continuous film, considering the suitability of GaN semiconductor substrate. The fabricated MoS2/GaN vertical heterojunction showed excellent rectifying diode characteristics with a photovoltaic photoresponsivity under monochromatic light illumination. The X ray photoelectron spectroscopy (XPS) studies showed the conduction and valence band offset values are around 0.44 and 2.3 eV with type II band alignment in the fabricated heterojunction device. This will facilitate effective movement of photoexcited electrons across the MoS2 GaN junction, while a large valence band offset will prevent movement of holes towards the GaN, resulting in low recombination loss to obtain a photovoltage in the heterojunction device. Our study revealed the formation of large area homogenous MoS2 layers on GaN wafer for vertical heterojunction device application.",
"author_names": [
"Pradeep Desai",
"Ajinkya K Ranade",
"Mandar Shinde",
"Bhagyashri Todankar",
"Rakesh D Mahyavanshi",
"Masaki Tanemura",
"Golap Kalita"
],
"corpus_id": 209393252,
"doc_id": "209393252",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Growth of uniform MoS2 layers on free standing GaN semiconductor for vertical heterojunction device application",
"venue": "Journal of Materials Science: Materials in Electronics",
"year": 2019
},
{
"abstract": "Silicon substrates offer a variety of advantages over conventional LED substrates, including both their low cost and their compatibility with the existing semiconductor manufacturing infrastructure. Researchers have sought to avail themselves of these benefits by developing GaN LEDs on silicon substrates. Integration of the two materials, however, presents several technical challenges that have proven difficult to address. The main challenges are the large lattice mismatch between GaN and silicon and the large difference in thermal expansion coefficients. Solutions have begun to emerge in recent years, with Toshiba being the first to commercialize GaN on Si technology on 200mm substrates in 2013, and several companies now shipping GaN on Si LEDs. Toshiba has developed a novel buffer layer structure and MOCVD growth technology that controls strain, wafer bow, and cracking while also suppressing formation of dislocations. This technology allows for the growth of GaN epitaxial layers with minimal cracking and dislocation densities in the low 108 cm 2. Control of strain and wafer bow is critical for the epitaxial process, and this requires very fine control over both absolute wafer temperature and temperature uniformity. Toshiba's technology controls temperature uniformity very well, and Toshiba has demonstrated wavelength uniformity with s=2nm across a 200mm wafer. Thin film LEDs fabricated from these materials have efficiencies on par with the best efficiencies of LEDs grown on conventional substrates. Blue LED wall plug efficiencies of ~83% are demonstrated.",
"author_names": [
"William E Fenwick"
],
"corpus_id": 124760746,
"doc_id": "124760746",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Progress and challenges in GaN on Si LEDs",
"venue": "SPIE OPTO",
"year": 2016
},
{
"abstract": "Abstract Group III nitride semiconductors exhibit many ideal characteristics for solar water splitting, including a tunable energy bandgap across nearly the entire solar spectrum and suitable band edge positions for water oxidation and proton reduction under visible and near infrared light irradiation. To date, however, the best reported energy conversion efficiency for III nitride semiconductor photocathodes is still below 1% Here we report on the demonstration of a relatively efficient p type In0.42Ga0.58N photocathode, which is monolithically integrated on an n type nonplanar Si wafer through a GaN nanowire tunnel junction. The open pillar design, together with the nonplanar Si wafer can significantly maximize light trapping, whereas the tunnel junction reduces the interfacial resistance and enhances the extraction of photo generated electrons. In addition, photodeposited Pt nanoparticles on InGaN nanowire surfaces significantly improve the cathodic performance. The nanowire photocathode exhibits a photocurrent density of 12.3 mA cm 2 at 0 V vs. RHE and an onset potential of 0.79 V vs. RHE under AM 1.5 G one sun illumination. The maximum applied bias photon to current efficiency reaches 4% at ~0.52 V vs. RHE, which is one order of magnitude higher than the previously reported values for III nitride photocathodes. Significantly, no performance degradation was measured for over 30 h solar water splitting with a steady photocurrent density ~12 mA cm 2 without using any extra surface protection, which is attributed to the spontaneous formation of N terminated surfaces of InGaN nanowires to protect against photocorrosion.",
"author_names": [
"Yongjie Wang",
"Srinivas Vanka",
"Jiseok Gim",
"Yuanpeng Wu",
"Ronglei Fan",
"Yazhou Zhang",
"Jinwen Shi",
"Mingrong Shen",
"Robert Hovden",
"Zetian Mi"
],
"corpus_id": 115296707,
"doc_id": "115296707",
"n_citations": 20,
"n_key_citations": 0,
"score": 0,
"title": "An In0.42Ga0.58N tunnel junction nanowire photocathode monolithically integrated on a nonplanar Si wafer",
"venue": "Nano Energy",
"year": 2019
},
{
"abstract": "A novel normally off AIN/GaN metal oxide semiconductor high electron mobility transistors (MOSHEMT) on 100 mm Si substrates for high power applications is demonstrated for the first time by means of a selective thermal oxidation of AIN. The formation of a high quality insulating AION layer resulting from the dry thermal oxidation of AIN at 900 degC in oxygen has been identified by transmission electron microscopy and X ray photoelectron spectroscopy. The AIN thermal oxidation appears to be highly selective toward the SiN cap layer allowing the local depletion of the 2 D electron gas (self aligned to the gate) and thus the achievement of normally off operation. Threshold voltage (VT) of +0.8 V and drain leakage current at VGS 0 V well below 1 mA/mm are obtained reproducibly over the wafer. The comparison of the fabricated MOSHEMTs with the control sample (identical but nonoxidized) reveals a drastic shift of VT toward positive values and three to four orders of magnitude drain leakage current reduction.",
"author_names": [
"Farid Medjdoub",
"Marleen Van Hove",
"Kai Cheng",
"Denis Marcon",
"Maarten Leys",
"Stefaan Decoutere"
],
"corpus_id": 2966019,
"doc_id": "2966019",
"n_citations": 21,
"n_key_citations": 0,
"score": 0,
"title": "Novel E Mode GaN on Si MOSHEMT Using a Selective Thermal Oxidation",
"venue": "IEEE Electron Device Letters",
"year": 2010
},
{
"abstract": "The present invention discloses an epitaxial wafer of making a GaN based light emitting diode and a manufacturing method belongs to the field of semiconductor technology. Epitaxial wafer includes a substrate, and a GaN nucleation layer is grown sequentially on the substrate, the undoped GaN layer, n type layer, a multiple quantum well layer and a p type layer, a multiple quantum well structure layer is a multi cycle, each period comprises the InGaN layer and the GaN layer, the periodic structure of the multi period n type layer in contact with a first period, the first period d GaN layer doped with Si, GaN and Si doped layer of the first period away from the first position of an adjacent layer, an InGaN layer adjacent the first layer in contact with the GaN layer of the first period. By the above described embodiment of the present invention, the dislocation can be reduced in the multiple quantum well layer, shield the polarization field, to improve the crystal quality, Si does not diffuse into the InGaN layer, avoids the formation of point defects in a multi quantum well layer, so that high recombination efficiency of electrons and holes, high luminous efficiency.",
"author_names": [
""
],
"corpus_id": 141211118,
"doc_id": "141211118",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Of making a GaN based LED epitaxial wafer and its manufacturing method",
"venue": "",
"year": 2013
},
{
"abstract": "Semiconductor CMOS nano electronics is intensively seeking solutions for future digital applications. One of the most promising solutions to deliver a technological breakthrough is exploring electron spin in metals and semiconductors with applications from spin transistors to quantum sensors, and quantum computing. Spintronic applications rely on magnetic semiconductor materials with suitable properties. In particular, dilute magnetic semiconductors (DMS) such as Mn doped GaN, show the great promise of a high Curie temperature (220K 370K) exceeding room temperature, and a large concentration of holes. These are all the essential pre requisites for operation of spin transistors in circuits. In this work, we dope an AlGaN/GaN heterostructure consisting of a GaN (2 nm) cap layer, an Al0.25Ga0.75N (25 nm) barrier, and a GaN (2 mm) substrate grown on a 6\" Si wafer with Mn by sputtering deposition and thermal annealing to create a dilute magnetic semiconductor material following the process flow. While initial attempts resulted in the formation of a MnO surface layer, the SEM/XDS and XPS data suggest a diffusion of Mn into the GaN layer using thermal annealing at 900*C for 7h with a concentration of 4.5% which is very close to the desired concentration of 5% needed for a DMS. The annealing temperature has to be below 1000* C since temperatures around 1000*C result in significant damage to the 2DEG and diffusion of Al from the AlGaN layer.",
"author_names": [
"J E Evans",
"Gregory Burwell",
"Frank C Langbein",
"Scott Shermer",
"Karol Kalna"
],
"corpus_id": 155538734,
"doc_id": "155538734",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Dilute magnetic contact for a spin GaN HEMT",
"venue": "",
"year": 2019
},
{
"abstract": "Abstract The commercialization of gallium nitride microwave circuits on diamond substrates requires chip dicing technology and via formation process compatible with standard semiconductor processes. This paper discusses issues related to dicing and drilling of GaN on diamond wafers for RF power transistor applications (die size 2 using laser micromachining.",
"author_names": [
"Dubravko I Babic",
"Quentin Diduck",
"Firooz N Faili",
"J G Wasserbauer",
"Frank Yantis Lowe",
"Daniel Francis",
"Felix Ejeckam"
],
"corpus_id": 108516981,
"doc_id": "108516981",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Laser machining of GaN on diamond wafers",
"venue": "",
"year": 2011
},
{
"abstract": "High power photoconductive semiconductor switching devices were fabricated from a high purity, semi insulating 4H SiC wafer. A highly n doped GaN subcontact layer was inserted between the contact metal and the high resistivity SiC wafer. The minimum ON state resistance of the device was less than 1 ohm when the energy of a 355 nm laser was 10.5 mJ with a bias voltage of 6 kV. The maximum device lifetime is 3151 pulses, after which the device completely fails. The failure mechanisms are determined using several analysis methods. Under a strong electric field, the failure mechanism differs for the two electrodes. Near the edge of the anode electrode, the switch is damaged due to the thermal stress caused by impact ionization. At the edge of the cathode electrode, the electrode erosion is the main reason for the failure to operate for long periods of time. These two different damage mechanisms are both important factors influencing the device performance. The electron avalanche breakdown at the edge of the anode electrode causes the formation of cracks between the electrodes, which is the root cause of the switch failure.",
"author_names": [
"Longfei Xiao",
"Xianglong Yang",
"Peng Duan",
"Huayong Xu",
"Xiu-fang Chen",
"Xiaobo Hu",
"Yan Peng",
"Xian'gang Xu"
],
"corpus_id": 14003281,
"doc_id": "14003281",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Effect of electron avalanche breakdown on a high purity semi insulating 4H SiC photoconductive semiconductor switch under intrinsic absorption.",
"venue": "Applied optics",
"year": 2018
}
] |
Semiconductor physics and devices | [
{
"abstract": "",
"author_names": [
"Manoj Kumar Majumder",
"Vijay Rao Kumbhare",
"Aditya Japa",
"Brajesh Kumar Kaushik"
],
"corpus_id": 224958152,
"doc_id": "224958152",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Semiconductor Physics and Devices",
"venue": "",
"year": 2020
},
{
"abstract": "Neamen's Semiconductor Physics and Devices, Third Edition. deals with the electrical properties and characteristics of semiconductor materials and devices. The goal of this book is to bring together quantum mechanics, the quantum theory of solids, semiconductor material physics, and semiconductor device physics in a clear and understandable way. Table of contents Prologue Semiconductor and the Integrated Circuit 1 The Crystal Structure of Solids 2 Introduction to Quantum Mechanics 3 Introduction to the Quantum Theory of Solids 4 The Semiconductor in Equilibrium 5 Carrier Transport Phenomena 6 Nonequilibrium Excess Carriers in Semiconductors 7 The pn Junction 8 The pn Junction Diode 9 Metal Semiconductor and Semiconductor Heterojunctions 10 The Bipolar Transistor 11 Fundamentals of the Metal Oxide Semiconductor Field Effect Transistor 12 Metal Oxide Semiconductor Field Effect Transistor: Additional Concepts 13 The Junction Field Effect Transistor 14 Optical Devices 15 Semiconductor Power Devices Appendix A Selected List of Symbols Appendix B System of Units, Conversion Factors, and General Constants Appendix C The Periodic TableAppendix D The Error FunctionAppendix E \"Derivation\" of Schrodinger's Wave EquationAppendix F Unit of Energy The Electron VoltAppendix G Answers to Selected Problems",
"author_names": [
"Donald A Neamen"
],
"corpus_id": 107677130,
"doc_id": "107677130",
"n_citations": 811,
"n_key_citations": 47,
"score": 0,
"title": "Semiconductor physics and devices",
"venue": "",
"year": 1992
},
{
"abstract": "Part I Semiconductor Material Properties Chapter 1: The Crystal Structure of Solids Chapter 2: Introduction to Quantum Mechanics Chapter 3: Introduction to the Quantum Theory of Solids Chapter 4: The Semiconductor in Equilibrium Chapter 5: Carrier Transport Phenomena Chapter 6: Nonequilibrium Excess Carriers in Semiconductors Part II Fundamental Semiconductor Devices Chapter 7: The pn Junction Chapter 8: The pn Junction Diode Chapter 9: Metal Semiconductor and Semiconductor Heterojunctions Chapter 10: Fundamentals of the Metal Oxide Semiconductor Field Effect Transistor Chapter 11: Metal Oxide Semiconductor Field Effect Transistor: Additional Concepts Chapter 12: The Bipolar Transistor Chapter 13: The Junction Field Effect Transistor Part III Specialized Semiconductor Devices Chapter 14: Optical Devices Chapter 15: Semiconductor Microwave and Power Devices Appendix A: Selected List of Symbols Appendix B: System of Units, Conversion Factors, and General Constants Appendix C: The Periodic Table Appendix D: Unit of Energy The Electron Volt Appendix E: \"Derivation\" of Schrodinger's Wave Equation Appendix F: Effective Mass Concepts Appendix G: The Error Function Appendix H: Answers to Selected Problems",
"author_names": [
"Donald A Neamen"
],
"corpus_id": 16587922,
"doc_id": "16587922",
"n_citations": 492,
"n_key_citations": 17,
"score": 0,
"title": "Semiconductor physics and devices basic principles",
"venue": "",
"year": 2012
},
{
"abstract": "Semiconductor Physics And DevicesSemiconductor Physics and ApplicationsGuided wave OpticsOptical Characterization of SemiconductorsTheory of Optical Processes in SemiconductorsPhotonic DevicesSemiconductor Integrated Optics for Switching LightOptical Properties of Semiconductor Quantum DotsCompound Semiconductors 2001Disordered Semiconductors Second EditionSemiconductor Physics and ApplicationsElectrical and Optical Properties of SemiconductorsWho's who in Technology TodayAdvanced Optical Materials, Technologies, and DevicesPhysics of Photonic DevicesPhysics of Photonic DevicesOptical Semiconductor DevicesHigh Pressure in Semiconductor Physics IIDevices for OptoelectronicsPhysics of Optoelectronic DevicesWide Bandgap Semiconductor Power DevicesCompound Semiconductors 2001Semiconductor PhysicsSemiconductor Device Physics and DesignCompound SemiconductorsAdvanced Optical Devices, Technologies, and Medical ApplicationsSemiconductor OpticsPhysics of SemiconductorsNonlinear Optics in SolidsTheory of Optical Processes in SemiconductorsIntroduction to Applied Solid State PhysicsOptical Processes in SemiconductorsHigh Pressure Semiconductor Physics IOptical Properties of Semiconductor NanocrystalsSemiconductor Optoelectronic DevicesQuantum Theory of the Optical and Electronic Properties of SemiconductorsSemiconductor Quantum OpticsSemiconductor Physics And OptoelectronicsOptical Properties of Semiconductor Quantum DotsFundamentals of Semiconductor Theory and Device Physics",
"author_names": [],
"corpus_id": 235260733,
"doc_id": "235260733",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Optical Devices From Semiconductor Physics And Devices 4th Edition",
"venue": "",
"year": 2019
},
{
"abstract": "",
"author_names": [
"Donald A Neamen Zhu"
],
"corpus_id": 201241138,
"doc_id": "201241138",
"n_citations": 235,
"n_key_citations": 28,
"score": 0,
"title": "Semiconductor physics and devices basic principles",
"venue": "",
"year": 1991
},
{
"abstract": "Preface. Introduction. PART I: SEMICONDUCTOR PHYSICS. Energy Bands and Carrier Concentration in Thermal Equilibrium. Carrier Transport Phenomena. PART II: SEMICONDUCTOR DEVICES. p n Junction. Bipolar Transistor and Related Devices. MOSFET and Related Devices. MESFET and Related Devices. Microwave Diodes, Quantum Effect, and Hot Electron Devices. Photonic Devices. PART III: SEMICONDUCTOR TECHNOLOGY. Crystal Growth and Epitaxy. Film Formation. Lithography and Etching. Impurity Doping. Integrated Devices. Appendix A: List of Symbols. Appendix B: International Systems of Units (SI Units) Appendix C: Unit Prefixes. Appendix D: Greek Alphabet. Appendix E: Physical Constants. Appendix F: Properties of Important Element and Binary Compound Semiconductors at 300 K. Appendix G: Properties of Si and GaAs at 300 K. Appendix H: Derivation of the Density of States in Semiconductor. Appendix I: Derivation of Recombination Rate for Indirect Recombination. Appendix J: Calculation of the Transmission Coefficient for a Symmetric Resonant Tunneling Diode. Appendix K: Basic Kinetic Theory of Gases. Appendix L: Answers to Selected Problems. Index.",
"author_names": [
"S M Sze"
],
"corpus_id": 93226361,
"doc_id": "93226361",
"n_citations": 3382,
"n_key_citations": 222,
"score": 0,
"title": "Semiconductor Devices: Physics and Technology",
"venue": "",
"year": 1985
},
{
"abstract": "General characterization of semiconductors electronic structure of ideal crystals electronic structure of semiconductor crystals in the presence of internal and external perturbations electron system in thermodynamic equilibrium interaction of semiconductors with light non equilibrium processes in semiconductors semiconductor junctions in thermodynamic equilibrium semiconductor junctions at non equilibrium.",
"author_names": [
"Rolf Enderlein",
"Norman J Morgenstern Horing"
],
"corpus_id": 137549649,
"doc_id": "137549649",
"n_citations": 74,
"n_key_citations": 1,
"score": 0,
"title": "Fundamentals Of Semiconductor Physics And Devices",
"venue": "",
"year": 1997
},
{
"abstract": "",
"author_names": [
"Shariful Islam"
],
"corpus_id": 139393620,
"doc_id": "139393620",
"n_citations": 12,
"n_key_citations": 2,
"score": 0,
"title": "Semiconductor Physics and Devices",
"venue": "",
"year": 2005
},
{
"abstract": "semiconductor devices theory and application open. semiconductor physics and devices 4th edition solutions. semiconductor physics and devices int l ed donald a. semiconductor physics and devices cornell engineering. semiconductors the physics hypertextbook. semiconductor physics and devices 3rd ed j neamen pdf. pdf semiconductor physics and devices basic principles. semiconductor device physics and design. physics notes class 12 chapter 14 semiconductor. semiconductor physics and devices donald neamen google. semiconductor physics and devices basic principles d a. types of semiconductor devices and applications. semiconductor physics and devices basic principles. semiconductor device. semiconductor physics and devices mcgraw hill. pdf semiconductor physics and devices by donald neamen. physics of semiconductor devices simon m sze kwok k. semiconductor physics amp devices ntu singapore. semiconductor devices specialization introduction. semiconductor physics and devices guide books. semiconductor physics and devices materials science and. semiconductor physics and devices oxford university press. semiconductor devices physics and technology 3rd edition. semiconductor physics article about semiconductor. electronics i semiconductor physics and devices. introduction to semiconductor physics and devices. physics of semiconductor devices 3rd edition wiley. solution manual for physics of semiconductor devices by. semiconductor physics and devices neamen 9780071070102. a theoretical boost to nano scale devices. semiconductor devices types of semiconductor devices. pdf semiconductor physics and devices by donald neamen. what is the best book on semiconductor devices quora. semiconductor physics and devices basic principles. semiconductor definition types materials applications. semiconductor devices dissidents. semiconductor basics amp semiconductor physics tutorial. semiconductor physics and devices pdf free download. semiconductor devices physics. principles of semiconductor devices. semiconductor. buy semiconductor physics and devices sie book online at. semiconductor physics coursera. semiconductor devices properties types examples. physics of semiconductor devices wiley online books. semiconductor physics and devices neamen donald a. semiconductor physics and devices basic principles by. physics of semiconductor devices springerlink",
"author_names": [
"Donald A Neamen"
],
"corpus_id": 124633950,
"doc_id": "124633950",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Semiconductor physics and devices by Donald A. Neamen",
"venue": "",
"year": 2003
},
{
"abstract": "Density of States function, g(E) Fermi Dirac Distribution function, f(E) Distribution Function and Fermi Energy Equilibrium Distribution of Electrons and Holes n0 and p0 Equation Intrinsic carrier concentration Fermi level for Intrinsic Semiconductor Extrinsic Semiconductor Position of the Fermi Level of the Extrinsic Semiconductor Non Degenerated Semiconductor Variation of EF with Doping Concentration and with Temperature Compensated Semiconductor Statistics of donors and acceptors Formula to remember Question Bank Solved problems Assignment",
"author_names": [
"S M Sze"
],
"corpus_id": 171088339,
"doc_id": "171088339",
"n_citations": 3756,
"n_key_citations": 590,
"score": 1,
"title": "PHYSICS OF SEMICONDUCTOR DEVICES",
"venue": "",
"year": 2007
}
] |
Degenerate four-wave mixing in semiconductor-doped glasses | [
{
"abstract": "We report degenerate four wave mixing (DFWM) of visible radiation in borosilicate glasses doped with crystallites of the mixed semiconductor CdS x Se 1 x These semiconductor doped glasses available commercially in the form of colored glass filters exhibit third order nonlinearities of ~10 9 10 8 esu for DFWM with short ~10 nsec) laser pulses at various visible wavelengths. Our studies on the temporal decay of the transient gratings indicate that the nonlinearity is not thermal in origin but may be attributed to the generation of a short lived electron hole plasma. In contrast with DFWM experiments in other semiconductors invoking gratings of optically generated carriers (or other mobile particles) we report unique diffusion independent decay of the gratings in these glasses; this is deduced from the dependence of the intensity and polarization of the DFWM signal on the polarization combinations of the input beams. Finally, we report detailed data on the aberration correction properties of these isotropic glasses.",
"author_names": [
"Ravinder K Jain",
"Richard C Lind"
],
"corpus_id": 100440687,
"doc_id": "100440687",
"n_citations": 647,
"n_key_citations": 1,
"score": 1,
"title": "Degenerate four wave mixing in semiconductor doped glasses",
"venue": "",
"year": 1983
},
{
"abstract": "",
"author_names": [
"K S Bindra",
"Shrikant M Oak",
"Kailash C Rustagi"
],
"corpus_id": 121343995,
"doc_id": "121343995",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "Degenerate four wave mixing in semiconductor doped glasses below the absorption edge",
"venue": "",
"year": 1999
},
{
"abstract": "A model for nonlinear transmission and degenerate four wave mixing in semiconductor doped glasses was developed and compared with experiment. The results of a plasma screening theory were used to model the nonlinear response of the semiconductor microcrystallites. The effects of carrier density dependent relaxation times, two photon absorption, free carrier absorption, and background absorption were included in the analysis. Good agreement between theoretical predictions and both nonlinear transmission and degenerate four wave mixing experiments at l 532 nm was obtained for 15 nsec laser pulses. For 30 psec pulses, with which higher intensities were available, features suggestive of two photon absorption and background absorption were observed. We conclude that free carrier absorption is not significant in these systems. Finally, it was shown that photodarkening is associated with the semiconductor crystallites in the glass matrix and that the host glass itself and unstruck samples exhibit little or no photodarkening.",
"author_names": [
"Kenneth W DeLong",
"Allan Gabel",
"Colin T Seaton",
"George I Stegeman"
],
"corpus_id": 122715370,
"doc_id": "122715370",
"n_citations": 43,
"n_key_citations": 0,
"score": 0,
"title": "Nonlinear transmission, degenerate four wave mixing, photodarkening, and the effects of carrier density dependent nonlinearities in semiconductor doped glasses",
"venue": "",
"year": 1989
},
{
"abstract": "NearlyDegenerateFour+WaveMixinginSemiconductor+dopedGlassesZHANGYun(Zhang Yun )ZHAOFeng(Zhao Feng (Dept.ofAppliedPhysics,HarbinInstituteofTe.",
"author_names": [
""
],
"corpus_id": 136980029,
"doc_id": "136980029",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Nearly Degenerate Four Wave Mixing in Semiconductor doped Glasses",
"venue": "",
"year": 1997
},
{
"abstract": "",
"author_names": [
"Zhao-Qing Feng"
],
"corpus_id": 139015215,
"doc_id": "139015215",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Nearly Degenerate Four Wave Mixing in Semiconductor doped Glasses",
"venue": "",
"year": 1997
},
{
"abstract": "Semiconductor doped glasses have been shown to exhibit large nonlinearities together with reasonably high transmissions near the band gap.1,2 Unfortunately, the nanosecond duration radiative recombination1 3 seems to hinder the use of such materials for high speed nonlinear applications. On the other hand, as the semiconductor concentration in these composite materials is relatively small the high overall transmission permits strongly saturating absorption of all crystallite with a moderate laser intensity. Therefore, Auger recombination can play an important role at the high free carrier concentration achieved in such a case and strongly decrease the radiative lifetime of the material.",
"author_names": [
"Frederic de Rougemont",
"Robert Frey"
],
"corpus_id": 93601159,
"doc_id": "93601159",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Intracavity nearly degenerate four wave mixing in optically saturated semiconductor doped glasses",
"venue": "",
"year": 1987
},
{
"abstract": "The fidelity of phase conjugation by degenerate four wave mixing in ruby and semiconductor doped glasses has been measured by means of our own modified Twyman Green interferometer [Opt. Lett. 14, 183 (1989) implementing two phase conjugate mirrors. It is shown that the fidelity of phase conjugators with an OG530 color filter as the nonlinear medium reaches a value of 99% The fidelity of ruby is also reported. Additionally the effect of the recording system on the value of the fidelity is discussed.",
"author_names": [
"Solomon M Saltiel",
"B M Van Wonterghem",
"Dimitri A Parthenopoulos",
"Tracy E Dutton",
"Peter M Rentzepis"
],
"corpus_id": 120442646,
"doc_id": "120442646",
"n_citations": 6,
"n_key_citations": 0,
"score": 0,
"title": "Fidelity of optical phase conjugation by degenerate four wave mixing in semiconductor glasses and ruby",
"venue": "",
"year": 1989
},
{
"abstract": "The time dependence of both the photoluminescence due to carrier recombination and the gratings created by degenerate four wave mixing were measured in semiconductor doped color filter glasses. Values ranging from 80 to less than 16 ps (laser pulse width limited) are measured in several different samples at various excitation levels. A slower mechanism, believed to be thermal in nature, is also observed with a lifetime in excess of 9 ns.",
"author_names": [
"S S Yao",
"Chris K Karaguleff",
"Allan Gabel",
"Rance M Fortenberry",
"Colin T Seaton",
"George I Stegeman"
],
"corpus_id": 123481025,
"doc_id": "123481025",
"n_citations": 181,
"n_key_citations": 1,
"score": 0,
"title": "Ultrafast carrier and grating lifetimes in semiconductor doped glasses",
"venue": "",
"year": 1985
},
{
"abstract": "We present a phenomenological theory of the intensity dependent dielectric function of semiconductor doped glasses near the absorption edge. It is shown that efficient phase conjugation by degenerate four wave mixing should be possible in these materials.",
"author_names": [
"Kailash C Rustagi",
"Christos Flytzanis"
],
"corpus_id": 21487216,
"doc_id": "21487216",
"n_citations": 67,
"n_key_citations": 0,
"score": 0,
"title": "Optical nonlinearities in semiconductor doped glasses.",
"venue": "Optics letters",
"year": 1984
},
{
"abstract": "Using time resolved techniques, absorption recovery, and degenerate four wave mixing, we directly observe the nonexponential intensity dependent recombination of free carriers photoexcited in semiconductor doped glasses. We assign this behavior to Auger recombination.",
"author_names": [
"Philippe Roussignol",
"Martin Kull",
"Daniel Ricard",
"Frederic de Rougemont",
"Robert Frey",
"Christos Flytzanis"
],
"corpus_id": 94800703,
"doc_id": "94800703",
"n_citations": 66,
"n_key_citations": 0,
"score": 0,
"title": "Time resolved direct observation of Auger recombination in semiconductor doped glasses",
"venue": "",
"year": 1987
}
] |
Diode-pumped passively mode-locked Nd:GdVO4 laser at 912 nm, | [
{
"abstract": "We have demonstrated the stable mode locked Nd:GdVO4 laser operating on the F 4(3/2) I 4(9/2) transition at 912 nm. With a four mirror folded cavity and a semiconductor saturable absorber mirror for passive mode locking, we have gained 6.5 ps laser pulses at a repetition rate of 178 MHz. The laser is diode end pumped, and the total output Power from the out coupler is 128 mw at an incident pump power of 19.7 W. (C) 2008 Elsevier B.V. All rights reserved.",
"author_names": [
"Changwen Xu",
"Zhiyi Wei",
"Kunna He",
"Dehua Li",
"Yong-dong Zhang",
"Zhi-Guo Zhang"
],
"corpus_id": 122042498,
"doc_id": "122042498",
"n_citations": 7,
"n_key_citations": 0,
"score": 1,
"title": "Diode pumped passively mode locked Nd:GdVO4 laser at 912 nm",
"venue": "",
"year": 2008
},
{
"abstract": "We demonstrated the first mode locked Nd:GdVO4 laser of 912 nm. Using a semiconductor saturable absorber mirror for passive mode locking, stable output power of 30.8 mW is obtained at a repetition rate of 152 MHz.",
"author_names": [
"Chi Zhang",
"Ling Zhang",
"Chunyu Zhang",
"Dehua Li",
"Zhiyi Wei",
"Zhi-Guo Zhang",
"Wenbo Li"
],
"corpus_id": 135508279,
"doc_id": "135508279",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Diode Pumped Passively Mode Locked 912 nm Nd:GdVO4 Laser",
"venue": "",
"year": 2006
},
{
"abstract": "Abstract A high power diode end pumped passively Q switched and mode locking (QML) Nd:GdVO4 laser at 912 nm was demonstrated for the first time, to the best of our knowledge. A Z type laser cavity with Cr4+:YAG crystals as the intracavity saturable absorber were employed in the experiments. Influence of the initial transmission (TU) of the saturable absorber on the QML laser performance was investigated. Using the TU 95% Cr4+:YAG, as much as an average output power of 2.0 W pulsed 912 nm laser was produced at an absorbed pump power of 25.0 W, then the repetition rates of the Q switched envelope and the mode locking pulse were 224 kHz and 160 MHz, respectively. Whereas the maximum output power was reduced to 1.3 W using the TU 90% Cr4+:YAG, we obtained a 100% modulation depth for the mode locking pulses inside the Q switched envelope.",
"author_names": [
"F Chen",
"Xin Yu",
"Xudong Li",
"Renpeng Yan",
"Cheng Wang",
"Deying Chen",
"Zhonghua Zhang",
"Junhua Yu"
],
"corpus_id": 121211497,
"doc_id": "121211497",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "High power diode pumped passively Q switched and mode locking Nd:GdVO4 laser at 912 nm",
"venue": "",
"year": 2011
},
{
"abstract": "Stable mode locking laser pulse at 942nm by diode pumped Nd:GSAG laser has been demonstrated for the first time. We obtained 8.7 ps pulses at repetition rate of 95.6 MHz and average output power of 220 mW.",
"author_names": [
"Changwen Xu",
"Zhiyi Wei",
"Yong-dong Zhang",
"Dehua Li",
"Zhiguo Zhang",
"Xuyang Wang",
"Frank Kallmeyer",
"Shanpeng Wang",
"A Ding",
"Hans Joachim Eichler",
"Chunyu Zhang",
"Chun-qing Gao"
],
"corpus_id": 7585810,
"doc_id": "7585810",
"n_citations": 9,
"n_key_citations": 0,
"score": 0,
"title": "Diode pumped passively mode locked Nd: GSAG laser at 942nm",
"venue": "2009 Conference on Lasers Electro Optics The Pacific Rim Conference on Lasers and Electro Optics",
"year": 2009
},
{
"abstract": "The electrical properties of Cr:YAG crystal had been calculated as dielectric constant (e) dielectric time (tdie) permittivity (Ie) permeability (m) electrical response time (TE) laser wave propagation speed through crystal (VP) skin depth (d) electrical susceptibility (kh crystal impedance (Z electrical conductivity (s induced electrical polarization (Pin) molar polarization (rp) and wave number (K) and some of other properties as transmittance (T) and refractive index(n) at (90% and 95% initial transmission for saturable absorber (Tu) in the passively Q switched mode locked (QML) Nd:GdVO4 laser system at (912nm) It can be concluded that each of electrical and magnetic flux density in Cr:YAG crystal which was incurrence to laser wave are mainly dependent on free electrons exists in it while the electrical polarization are dependent on the number of crystal molecules in the ground state",
"author_names": [
"Methaq Mutter Mehdy AL-Sultani"
],
"corpus_id": 62775391,
"doc_id": "62775391",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Study Of The Electrical Properties For Cr+4:YAG Crystal In A Passively Q Switched Mode Locked (QML) Nd:Gdvo4 Laser At 912 Nm",
"venue": "",
"year": 2013
},
{
"abstract": "We demonstrated a mode locked Nd:GdVO4 laser of operating at 912 nm. Using a semiconductor saturable absorber mirror for passive mode locking, stable output power of 22.6 mW is obtained at a repetition rate of 176 MHz.",
"author_names": [
"Ling Zhang",
"Chi Zhang",
"Dehua Li",
"Chunyu Zhang",
"Yongbing Long",
"Zhiguo Zhang",
"Zhiyi Wei"
],
"corpus_id": 20920902,
"doc_id": "20920902",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Passively mode locked 912nm Nd:GdVO4 laser",
"venue": "2006 Conference on Lasers and Electro Optics and 2006 Quantum Electronics and Laser Science Conference",
"year": 2006
},
{
"abstract": "We have demonstrated a passively mode locked diode end pumped all solid state laser, which is composed of a Nd:Gd0.5Y0.5VO4 crystal and a folded cavity with a semiconductor saturable absorber mirror grown by metal organic chemical vapor deposition. Stable cw mode locking with a 3.8 ps pulse duration at a repetition rate of 112 MHz was obtained. At 13.6 W of the incident pump power, a clean mode locked fundamental mode average output power of 3.9 W was achieved with an overall optical to optical efficiency of 29.0% and the slope efficiency was 38.1%",
"author_names": [
"Jing-Liang He",
"Ya-Xian Fan",
"Juan Du",
"Yong-gang Wang",
"Sheng Liu",
"Hui-Tian Wang",
"Lian-han Zhang",
"Yin Hang"
],
"corpus_id": 24655935,
"doc_id": "24655935",
"n_citations": 101,
"n_key_citations": 2,
"score": 0,
"title": "4 ps passively mode locked Nd:Gd0.5Y0.5VO4 laser with a semiconductor saturable absorber mirror.",
"venue": "Optics letters",
"year": 2004
},
{
"abstract": "We describe here the use of a 798 nm stabilized high brightness tapered laser diode to pump a Nd:ASL crystal for 900 nm laser operation. An output power of 150 mW is obtained.",
"author_names": [
"David Paboeuf",
"Gaelle Lucas-Leclin",
"Patrick M Georges",
"Bernd Sumpf",
"Gotz Erbert",
"Cyrille Varona",
"Pascal Loiseau",
"Gerard Aka",
"Bernard Ferrand"
],
"corpus_id": 181397,
"doc_id": "181397",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "900 nm Emission of a Nd:ASL Laser Pumped by an Extended Cavity Tapered Laser Diode",
"venue": "",
"year": 2007
},
{
"abstract": "Passive mode locking of a Nd:KGW laser with hot band diode pumping at 910 nm was demonstrated. A semiconductor saturable absorber mirror was used as a mode locking mechanism. The laser generated 2.4 ps pulses at a repetition rate of ~83.8 MHz. An average output power of 87 mW was obtained at 1067 nm. To the best of our knowledge, this is the first report on passive mode locking of a Nd:KGW laser with low quantum defect pumping which holds great promise for further output power scaling.",
"author_names": [
"Wei Lin",
"Shota Sawai",
"Aruto Hosaka",
"Hikaru Kawauchi"
],
"corpus_id": 204793703,
"doc_id": "204793703",
"n_citations": 6,
"n_key_citations": 1,
"score": 0,
"title": "Passive mode locking of a Nd:KGW laser with hot band diode pumping",
"venue": "",
"year": 2016
},
{
"abstract": "Mode locking technique is a widely used method for generating ultrashort laser pulses. The mode locked laser output is a sequence of equally spaced laser pulses. The pulse width is limited by the spectral range of the gain medium and inversely related to the bandwidth of the laser emission. Compared with the active mode locking technique, passively modelocked laser with saturable absorber is able to generate much shorter pulse with a simple configuration. In particularly, based on the passive mode locking mechanism, the Kerr lens mode locking (KLM) Ti:sapphire laser is recognized as the most important ultrafast laser source. Not only a series of commercial femtosecond lasers with Ti:sapphire crystal were released, but also lead to many innovations in science, such as frequency comb, laser wake field acceleration, attosecond science, laser micro fabrication etc. However, the major drawback of Ti:sapphire laser is its green pump laser source. Currently available green lasers generated by frequency doubled Nd:YAG laser or by Argon laser are relatively bulky and expensive, which limits the practical application of ultrafast Ti:sapphire lasers.",
"author_names": [
"Zhiyi Wei",
"Binbin Zhou",
"Yong-dong Zhang",
"Yuwan Zou",
"Xinming Zhong",
"Changwen Xu",
"Zhiguo Zhang"
],
"corpus_id": 13879942,
"doc_id": "13879942",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "All Solid State Passively Mode Locked Ultrafast Lasers Based on Nd, Yb, and Cr Doped Media",
"venue": "",
"year": 2012
}
] |
Reconfigurable 3D plasmonic metamolecules | [
{
"abstract": "A reconfigurable plasmonic nanosystem combines an active plasmonic structure with a regulated physical or chemical control input. There have been considerable efforts on integration of plasmonic nanostructures with active platforms using top down techniques. The active media include phase transition materials, graphene, liquid crystals and carrier modulated semiconductors, which can respond to thermal, electrical and optical stimuli. However, these plasmonic nanostructures are often restricted to two dimensional substrates, showing desired optical response only along specific excitation directions. Alternatively, bottom up techniques offer a new pathway to impart reconfigurability and functionality to passive systems. In particular, DNA has proven to be one of the most versatile and robust building blocks for construction of complex three dimensional architectures with high fidelity. Here we show the creation of reconfigurable three dimensional plasmonic metamolecules, which execute DNA regulated conformational changes at the nanoscale. DNA serves as both a construction material to organize plasmonic nanoparticles in three dimensions, as well as fuel for driving the metamolecules to distinct conformational states. Simultaneously, the three dimensional plasmonic metamolecules can work as optical reporters, which transduce their conformational changes in situ into circular dichroism changes in the visible wavelength range.",
"author_names": [
"Anton Kuzyk",
"Robert Dipl -Ing Schreiber",
"Hui Zhang",
"Alexander O Govorov",
"Tim Liedl",
"Na Liu"
],
"corpus_id": 10896687,
"doc_id": "10896687",
"n_citations": 410,
"n_key_citations": 3,
"score": 1,
"title": "Reconfigurable 3D plasmonic metamolecules.",
"venue": "Nature materials",
"year": 2014
},
{
"abstract": "Plasmonic metamolecules have many peculiar properties and have been applied in biological and materials science such as in reconfigurable 3D building blocks for complex nano architectures and imaging probes for high resolution sensing. In these applications, fast detection of the bond angles of the sub wavelength metamolecules is highly desired. However, angle detection is not the same as orientation detection. The two orientations must be determined simultaneously, and common orientation sensors can only measure one. In this work, we propose and demonstrate a method to resolve the bond angle of a plasmonic metamolecule composed of three spherical nanoparticles. The detection of the bond angle is achieved via modulation depth analysis of polarization resolved dark field images. The underlying mechanism is found to be the opposing responses of the longitudinal and transversal bonding modes to the polarization variation of the incident light. In addition, the spectrally degenerate structures are further distinguished by the spot center localization method. This method may pave the way for practical application of plasmonic metamolecules.",
"author_names": [
"Yanrong Wang",
"Ruqiang Zheng",
"Yufeng Ding",
"Wenjun Fan",
"Dahe Liu",
"Jing Zhou",
"Jinwei Shi"
],
"corpus_id": 216819490,
"doc_id": "216819490",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Resolving the bond angle of a plasmonic metamolecule",
"venue": "",
"year": 2017
},
{
"abstract": "Atomic force microscopy (AFM) nanomanipulation has been viewed as a deterministic method for the assembly of plasmonic metamolecules because it enables unprecedented engineering of clusters with exquisite control over particle number and geometry. Nevertheless, the dimensionality of plasmonic metamolecules via AFM nanomanipulation is limited to 2D, so as to restrict the design space of available artificial electromagnetisms. Here, we show that 2D nanomanipulation of the AFM tip can be used to assemble 3D plasmonic metamolecules in a versatile and deterministic way by dribbling highly spherical and smooth gold nanospheres (NSs) on a nanohole template rather than on a flat surface. Various 3D plasmonic clusters with controlled symmetry were successfully assembled with nanometer precision, the relevant 3D plasmonic modes (i.e. artificial magnetism and magnetic based Fano resonance) were fully rationalized by both numerical calculation and dark field spectroscopy. This templating strategy for advancing AFM nanomanipulation can be generalized to exploit the fundamental understanding of various electromagnetic 3D couplings and can serve as the basis for the design of metamolecules, metafluids, and metamaterials.",
"author_names": [
"Kyung jin Park",
"Ji-Hyeok Huh",
"Daewoong Jung",
"Jin-Sung Park",
"Gwan Hyun Choi",
"Gaehang Lee",
"Pil J Yoo",
"Hong-Gyu Park",
"Gi-Ra Yi",
"Seungwoo Lee"
],
"corpus_id": 119332793,
"doc_id": "119332793",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Assembly of 3D plasmonic metamolecules by 2D AFM nanomanipulation of highly uniform and smooth gold nanospheres",
"venue": "",
"year": 2017
},
{
"abstract": "We demonstrate a reconfigurable 3D plasmonic nanomachine, which operates in the visible wavelength range. The conformation of this 3D nanomachine can be actively switched through DNA mediated molecular processes in a fully programmable manner.",
"author_names": [
"Laura Na Liu",
"Anton Kyzyk",
"Robert Dipl -Ing Schreiber",
"Hui Zhang",
"Alexander O Govorov",
"Tim Liedl"
],
"corpus_id": 138942833,
"doc_id": "138942833",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "A Reconfigurable 3D Plasmonic Nanomachine",
"venue": "",
"year": 2014
},
{
"abstract": "DNA origami nanotechnology enables selective reconfiguration of plasmonic quasi enantiomers through simple pH tuning. Selective configuration control of plasmonic nanostructures using either top down or bottom up approaches has remained challenging in the field of active plasmonics. We demonstrate the realization of DNA assembled reconfigurable plasmonic metamolecules, which can respond to a wide range of pH changes in a programmable manner. This programmability allows for selective reconfiguration of different plasmonic metamolecule species coexisting in solution through simple pH tuning. This approach enables discrimination of chiral plasmonic quasi enantiomers and arbitrary tuning of chiroptical effects with unprecedented degrees of freedom. Our work outlines a new blueprint for implementation of advanced active plasmonic systems, in which individual structural species can be programmed to perform multiple tasks and functions in response to independent external stimuli.",
"author_names": [
"Anton Kuzyk",
"Maximilian J Urban",
"Andrea Idili",
"Francesco Ricci",
"Na Liu"
],
"corpus_id": 9677743,
"doc_id": "9677743",
"n_citations": 115,
"n_key_citations": 3,
"score": 0,
"title": "Selective control of reconfigurable chiral plasmonic metamolecules",
"venue": "Science Advances",
"year": 2017
},
{
"abstract": "Molecular chirality is a geometric property that is of great importance in chemistry, biology, and medicine. Recently, plasmonic nanostructures that exhibit distinct chiroptical responses have attracted tremendous interest, given their ability to emulate the properties of chiral molecules with tailored and pronounced optical characteristics. However, the optical chirality of such human made structures is in general static and cannot be manipulated postfabrication. Herein, different concepts to reconfigure the chiroptical responses of plasmonic nano and micro objects are outlined. Depending on the utilized strategies and stimuli, the chiroptical signature, the 3D structural conformation, or both can be reconfigured. Optical devices based on plasmonic nanostructures with reconfigurable chirality possess great potential in practical applications, ranging from polarization conversion elements to enantioselective analysis, chiral sensing, and catalysis.",
"author_names": [
"Frank Neubrech",
"Mario Hentschel",
"Na Liu"
],
"corpus_id": 211216230,
"doc_id": "211216230",
"n_citations": 17,
"n_key_citations": 0,
"score": 0,
"title": "Reconfigurable Plasmonic Chirality: Fundamentals and Applications.",
"venue": "Advanced materials",
"year": 2020
},
{
"abstract": "While in most existing terahertz communications systems, the THz carrier wave is transmitted via free space channels, the THz waveguide based integrated solutions can be of great utility at both the transmitter and receiver ends, thus simplifying the miniaturization and mass production of cost effective THz communications systems. Here we present a new type of modular THz integrated circuits based on the two wire plasmonic waveguide components fabricated using a combination of stereolithography (SLA) 3D printing, wet chemistry metal deposition, and hot stamping techniques. Particular attention is paid to the design of the optical circuits based on the two wire waveguides suspended inside a protective micro sized enclosure. Such waveguides feature low transmission and bending losses, as well as low dispersion. Using such waveguides as basic building blocks, we then demonstrate several key optical subcomponents, such as low loss broadband 2x1THz couplers that use two coalescing two wire waveguide bends, as well as broadband waveguide Bragg gratings that feature a paper sheet with a periodic sequence of metal strips inserted into the air gap of a two wire waveguide. Finally, using these developed subcomponents, a two channel add drop multiplexer is demonstrated to operate at 140 GHz. We believe that the reported micro encapsulated two wire waveguide based modular platform can have a strong impact on the field of THz signal processing and sensing due to the ease of device fabrication and handling, high degree of reconfigurability, and high potential for real time tunability.",
"author_names": [
"Yang Cao",
"Kathirvel Nallappan",
"Hichem Guerboukha",
"Guofu Xu",
"Maksim Skorobogatiy"
],
"corpus_id": 224961424,
"doc_id": "224961424",
"n_citations": 9,
"n_key_citations": 0,
"score": 0,
"title": "Additive manufacturing of highly reconfigurable plasmonic circuits for terahertz communications",
"venue": "",
"year": 2020
},
{
"abstract": "For the first time, we have successfully demonstrated a 3 dimensional (3 D) depth scan using an electrically tunable active metasurface, which is an array of plasmonic resonators with an active indium tin oxide (ITO) layer. Our active device can steer a beam in reflection with a positive side mode suppression ratio by independently controlling the amplitude and the phase from 0 to 360deg using two separate bias controls. These are very promising results for small and high speed 3D depth sensing for mobile and automotive applications.",
"author_names": [
"Sun Il Kim",
"Junghyun Park",
"Byung Gil Jeong",
"Duhyun Lee",
"Jungwoo Kim",
"Chang Gyun Shin",
"Chang Bum Lee",
"Tatsuhiro Otsuka",
"Sangwook Kim",
"Ki-Yeon Yang",
"Jisan Lee",
"Inoh Hwang",
"Jaeduck Jang",
"K H Ha",
"Hyuck Choo",
"Byoung Lyong Choi",
"Sungwoo Hwang"
],
"corpus_id": 232266449,
"doc_id": "232266449",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Electrically Reconfigurable Active Metasurface for 3D Distance Ranging",
"venue": "2020 IEEE International Electron Devices Meeting (IEDM)",
"year": 2020
},
{
"abstract": "Powered by TCPDF (www.tcpdf.org) This material is protected by copyright and other intellectual property rights, and duplication or sale of all or part of any of the repository collections is not permitted, except that material may be duplicated by you for your research use or educational purposes in electronic or print form. You must obtain permission for any other use. Electronic or print copies may not be offered, whether for sale or otherwise to anyone who is not an authorised user. Kuzyk, Anton; Urban, Maximilian J. Idili, Andrea; Ricci, Francesco; Liu, Na",
"author_names": [
"Anton Kuzyk",
"Maximilian J Urban",
"Andrea Idili",
"Francesco Ricci",
"Na Liu"
],
"corpus_id": 53680433,
"doc_id": "53680433",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Na Selective control of reconfigurable chiral plasmonic metamolecules",
"venue": "",
"year": 2017
},
{
"abstract": "A reconfigurable plasmonic nanosystem combines an active plasmonic structure with a regulated physical or chemical control input. There have been considerable e orts on integration of plasmonic nanostructures with active platforms using topdown techniques. The active media include phase transition materials, graphene, liquid crystals and carrier modulated semiconductors, which can respond to thermal1, electrical2 and optical stimuli3 5. However, these plasmonic nanostructures are often restricted to two dimensional substrates, showing desired optical response only along specific excitation directions. Alternatively, bottom up techniques o er a new pathway to impart reconfigurability and functionality to passive systems. In particular, DNAhas proven to be one of the most versatile and robust building blocks6 9 for construction of complex three dimensional architectureswith highfidelity10 14. Herewe show the creation of reconfigurable three dimensional plasmonic metamolecules, which execute DNA regulated conformational changes at the nanoscale. DNA serves as both a construction material to organize plasmonic nanoparticles in three dimensions, aswell as fuel for driving themetamolecules to distinct conformational states. Simultaneously, the threedimensional plasmonic metamolecules can work as optical reporters,which transduce their conformational changes in situ into circular dichroismchanges in the visiblewavelength range. Circular dichroism (CD) that is, differential absorption of leftand right handed circularly polarized light, of natural chiral macromolecules is highly sensitive to their three dimensional (3D) conformations15. Taking a similar strategy, we create 3D reconfigurable plasmonic chiral metamolecules4,16, whose conformation changes are highly correlated with their pronounced and distinct CD spectral changes in the visiblewavelength range. Figure 1a shows the design schematic. Two gold nanorods (AuNRs) are hosted on a reconfigurable DNA origami template7,10, which consists of two 14 helix bundles (80 nm x 16 nm x 8 nm) folded from a long single stranded DNA (ssDNA) scaffold with the help of hundreds of staple strands13. The two origami bundles are linked together by the scaffold strand passing twice between them at one point. To ensure the mobility of the DNA bundles and avoid the formation of a Holliday junction17, 8 unpaired bases are introduced to each ssDNA connector (Supplementary Note 1) Twelve binding sites are extended from each origami bundle for robust assembly of one AuNR (38 nm x 10 nm) functionalized with complementary DNA (Supplementary Note 2) The surface to surface distance of the two AuNRs is roughly 25 nm. Owing to close proximity, the excited plasmons in the two AuNRs can be strongly coupled18. The two crossed AuNRs constitute a 3D plasmonic chiral object19 22, which generates a theme of handedness when interacting with leftand right handed circularly polarized light, giving rise to strong CD. Left handed Right handed Relaxed R1 R2 Waste 1 Waste 2",
"author_names": [
"Anton Kuzyk",
"Robert Dipl -Ing Schreiber",
"Hui Zhang",
"Alexander O Govorov",
"Tim Liedl",
"Na Liu"
],
"corpus_id": 4998057,
"doc_id": "4998057",
"n_citations": 22,
"n_key_citations": 0,
"score": 0,
"title": "Reconfigurable 3 D plasmonic metamolecules",
"venue": "",
"year": 2014
}
] |
Lifetime wind converter | [
{
"abstract": "Fostering of high altitude wind energy (HAWE) resources above 200 meters is a recent promising technology that seeks to capture the strong wind currents at high elevations. Among the many concepts of airborne wind energy (AWE) generators, the soft kite pumping cycle (PC) concept promises to provide a very lightweight, high power density, and cost effective solution. In this study, the impact of the load cycle on the lifetime of the machine side converter (MSC) is examined. By employing a physics of failure estimation approach, the main pumping cycles and the machine speed reversal were identified as the primary adverse influencers of the IGBT and diode solder joints. Whereas, wind speeds around 12 m/s contribute the most to the predicted degradation. To fulfill the thermal limitations and the lifetime requirements of the application, an optimum converter dimension is found using linear scaling of the semiconductors chip area and the heatsink thermal impedances. With the generation (reel out) phase power defined as the base value, the results suggest that the converter needs to be scaled by at least 150 to meet the thermal constraints, and by 350 to approach the target lifetime of ten years.",
"author_names": [
"Bakr Bagaber",
"Patrick Junge",
"Axel Mertens"
],
"corpus_id": 222223302,
"doc_id": "222223302",
"n_citations": 0,
"n_key_citations": 0,
"score": 1,
"title": "Lifetime Estimation and Dimensioning of the Machine Side Converter for Pumping Cycle Airborne Wind Energy System",
"venue": "2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe)",
"year": 2020
},
{
"abstract": "Offshore wind energy is currently the leading offshore renewable energy technology and plays an essential role in achieving a low carbon economy in Europe. Offshore wind turbines, as a result of the harsher offshore environment, suffer from high O&M costs, and as such a high overall LCOE. These higher O&M costs can be reduced by focusing on the most critical subassemblies of the OWT, by either improving the reliability of the subassembly or by better understanding the failure mechanism, and thus optimizing the O&M strategy. The power converter is identified as one of the most critical subassemblies as risk of the operation of the OWT in terms of maintainability and availability. The reliability of the power converter is heavily influenced by both its steady state and its dynamic thermal behavior, and as such great attention will be paid to the literature related to the thermal behaviour of the power converter. This paper seeks to provide a comprehensive overview on how the typical mission profile of an OWT influences the thermal loading. The paper seeks to propose a comprehensive and up to date literature review related to the lifetime modelling of the power converter, and to highlight some of the main challenges yet to be tackled in the reliability analysis of the power converter, suggesting future areas of research.",
"author_names": [
"Cameron Simpson",
"Agusti Egea Alvarez",
"Maurizio Collu"
],
"corpus_id": 226267925,
"doc_id": "226267925",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Influence of the Mission Profile on The Lifetime Modelling of the Wind Turbine Power Converter A Review",
"venue": "2020 9th International Conference on Renewable Energy Research and Application (ICRERA)",
"year": 2020
},
{
"abstract": "One of the most important causes of failure in wind power systems is due to the failures of the power converter and due to one of its most critical components, the power semiconductor devices. This paper proposes a novel derating strategy for the wind turbine system based on the reliability performance of the converter and the total energy production throughout its entire lifetime. An advanced reliability design tool is first established and demonstrated, in which the wind power system together with the thermal cycling of the power semiconductor devices are modeled and characterized under a typical wind turbine system mission profile. Based on the reliability design tools, the expected lifetime of the converter for a given mission profile can be quantified under different output power levels, and an optimization algorithm can be applied to extract the starting point and the amount of converter power derating which is necessary in order to obtain the target lifetime requirement with a maximum energy production capability. A nonlinear optimization algorithm has been implemented and various case studies of lifetime requirements have been analyzed. Finally, an optimized derating strategy for the wind turbine system has been designed and its impact has been highlighted.",
"author_names": [
"Ionut Vernica",
"Ke Ma",
"Frede Blaabjerg"
],
"corpus_id": 24649794,
"doc_id": "24649794",
"n_citations": 16,
"n_key_citations": 0,
"score": 0,
"title": "Optimal Derating Strategy of Power Electronics Converter for Maximum Wind Energy Production with Lifetime Information of Power Devices",
"venue": "IEEE Journal of Emerging and Selected Topics in Power Electronics",
"year": 2018
},
{
"abstract": "A comparison has been made of the converter lifetime for a 3MW fully rated converter horizontal axis wind turbine located onshore and offshore. Simulated torque and speed of the turbine shaft were used to calculate voltage and current time series, that was used to calculate the junction temperatures of the diode and IGBT in the generatorside converter by a thermal electrical model. A rainssow counting algorithm was applied to the junction temperature in combination with an empirical model of the lifetime estimation, to calculate the lifetime of the power electronic modules in the turbine. The number of parallel modules for each location to achieve 20 years life time has also been found. Simulations show the lifetime consumption rate of the diode and IGBT is decreased exponentially by increasing number of parallel modules, lowering the average temperature. The offshore wind turbine has a higher lifetime consumption rate, requiring a slightly higher converter rating to achieve a 20 year lifetime, but this difference is small, and both turbines will use the same number of modules.",
"author_names": [
"Kamyab Givaki",
"Max A Parker",
"Peter Jamieson"
],
"corpus_id": 96462212,
"doc_id": "96462212",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Givaki, K and Parker, M and Jamieson, P (2014) Estimation of the power electronic converter lifetime in fully rated converter wind turbine for onshore and offshore wind farms. In: 7th IET International Conference on Power Electronics, Machines and Drives",
"venue": "",
"year": 2018
},
{
"abstract": "In wind farms (WF) the most popular and commonly implemented active power control method is the maximum power point tracking (MPPT) Due to the wake effect, the upstream wind turbine (WT) in WFs has more active power generation than the downstream WT at the wind directions and wind speeds that the WF has wake loss. In the case that WTs support the voltage control by reactive power, the upstream WT's power converter may have shorter lifetime even below the industrial standard. In this paper, based on the analysis of the wake effect, the reactive power capability of the doubly fed induction generator (DFIG) WT, and the lifetime of the DFIG WT's power converter, a reactive power dispatch method is proposed in the WF with DFIG WTs to improve the lifetime of the upstream WT's power converter. The proposed reactive power dispatch method is analyzed and demonstrated by the simulation on a WF with 80 DFIG WTs. It can be concluded that, compared with the traditional reactive power dispatch method, the proposed method can increase the lifetime of the upstream WT's power converter.",
"author_names": [
"Jie Tian",
"Dao Zhou",
"Chi Su",
"Zhe Chen",
"Frede Blaabjerg"
],
"corpus_id": 7624706,
"doc_id": "7624706",
"n_citations": 30,
"n_key_citations": 2,
"score": 0,
"title": "Reactive Power Dispatch Method in Wind Farms to Improve the Lifetime of Power Converter Considering Wake Effect",
"venue": "IEEE Transactions on Sustainable Energy",
"year": 2017
},
{
"abstract": "As a key component in the wind turbine system, the power electronic converter and its power semiconductors suffer from complicated power loadings related to environment, and are proven to have high failure rates. Therefore, correct lifetime estimation of wind power converter is crucial for the reliability improvement and also for cost reduction of wind power technology. Unfortunately, the existing lifetime estimation methods for the power electronic converter are not yet suitable in the wind power application, because the comprehensive mission profiles are not well specified and included. Consequently, a relative more advanced approach is proposed in this paper, which is based on the loading and strength analysis of devices and takes into account different time constants of the thermal behaviors in power converter. With the established methods for loading and lifetime estimation for power devices, more detailed information of the lifetime related performance in wind power converter can be obtained. Some experimental results are also included to validate the thermal behavior of power device under different mission profiles.",
"author_names": [
"Ke Ma",
"Marco Liserre",
"Frede Blaabjerg",
"Tamas Kerekes"
],
"corpus_id": 20741484,
"doc_id": "20741484",
"n_citations": 158,
"n_key_citations": 8,
"score": 0,
"title": "Thermal Loading and Lifetime Estimation for Power Device Considering Mission Profiles in Wind Power Converter",
"venue": "IEEE Transactions on Power Electronics",
"year": 2015
},
{
"abstract": "Abstract Power semiconductors in the wind turbine power converter system suffer from two scale thermal loadings, the fundamental frequency thermal cycling caused by the output frequency of converter and the low frequency thermal cycling due to the variation of long term wind speed. These two scale thermal loadings introduce different consumed lifetimes. Accurate lifetime estimation in the wind power application is desired for reliability prediction and health management. This paper adopts the Bayerer lifetime model to evaluate the consumed lifetime of power semiconductors in wind power converter systems based on a numerical junction temperature calculation method. Lifetime estimation can be improved by taking into account the ambient temperature. Studies show that fluctuations of the ambient temperature increase the consumed lifetime due to the low frequency thermal cycling, but have little effect on the consumed lifetime due to the fundamental frequency thermal cycling. Our results also show that the consumed lifetime due to fundamental frequency thermal cycling mainly falls on the high wind speed area, whereas the consumed lifetime due to low frequency thermal cycling is clustered in the area due to large low frequency junction temperature fluctuations. The resulting distribution characteristics can be used in the thermal management for reliability improvement.",
"author_names": [
"Xiong Du",
"Jun Zhang",
"Gaoxian Li",
"Heng-Ming Tai",
"Pengju Sun",
"Luowei Zhou"
],
"corpus_id": 30742270,
"doc_id": "30742270",
"n_citations": 14,
"n_key_citations": 1,
"score": 0,
"title": "Lifetime estimation for IGBT modules in wind turbine power converter system considering ambient temperature",
"venue": "Microelectron. Reliab.",
"year": 2016
},
{
"abstract": "The thermal dynamics of power semiconductors and power capacitors are closely related to the reliability and affect the cost of power electronic converter. However, the component loading in a wind turbine system is disturbed by many factors of the power converter, which presents various time constants from microseconds to hours. To determine the system availability in such system is a challenge and need detailed analysis. In the case of a mission profile with 1 hour sample rate, a simplified circuit model, loss model, and thermal model of the active power switches and passive capacitors are needed and described. According to the long term electrothermal profile, the percentile lifetime of a single component can be predicted. The Weibull function based time to failure distribution can then be used to link from component level to converter level reliability. From analysis of a 2 MW wind turbine system, it can be seen that the dc link capacitor bank dominates the converter level reliability.",
"author_names": [
"Dao Zhou",
"Frede Blaabjerg"
],
"corpus_id": 216586927,
"doc_id": "216586927",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Converter Level Reliability of Wind Turbine With Low Sample Rate Mission Profile",
"venue": "IEEE Transactions on Industry Applications",
"year": 2020
},
{
"abstract": "Back to back converters for wind turbine systems (WTS) feature capacitors in the DC link to maintain a stable DC link voltage and to decouple the generator from the grid. Electrolytic and film capacitors can be chosen to this purpose. Long term field experience and recorded failure data reveal that capacitor failures are one of the main reasons for the downtime of WTS. The ripple current accelerates the wear out of the capacitors, which is strongly dependent on the mission profile of the system. Therefore, it becomes important to estimate the useful lifetime of a capacitor as a function of the ripple current. In this paper, aging characteristics of electrolytic capacitors are described, and a power converter topology and its control strategy are designed to perform accelerated lifetime tests. The voltage and ripple current of the capacitor under test (CUT) can be controlled with low THD to correlate wear out with ripple.",
"author_names": [
"Youngjong Ko",
"Holger Jedtberg",
"Giampaolo Buticchi",
"Marco Liserre"
],
"corpus_id": 21109365,
"doc_id": "21109365",
"n_citations": 5,
"n_key_citations": 1,
"score": 0,
"title": "Topology and control strategy for accelerated lifetime test setup of DC link capacitor of wind turbine converter",
"venue": "2016 IEEE Applied Power Electronics Conference and Exposition (APEC)",
"year": 2016
},
{
"abstract": "As a key component in the wind turbine system, the power electronic converter and its power semiconductors suffer from complicated power loadings related to environment, and are proven to have high failure rates. Therefore, correct lifetime estimation of wind power converter is crucial for the reliability improvement and also for cost reduction of wind power technology. Unfortunately, the existing lifetime estimation methods for the power electronic converter are not yet suitable in the wind power application, because the comprehensive mission profiles are not well specified and included. Consequently, a relative more advanced approach is proposed in this paper, which is based on the loading and strength analysis of devices and takes into account different time constants of the thermal behaviors in power converter. With the established methods for loading and lifetime estimation for power devices, more detailed information of the lifetime related performance in wind power converter can be obtained. Some experimental results are also included to validate the thermal behavior of power device under different mission profiles. (The original version of this paper has been presented at Energy Conversion Congress and Expo ECCE' 2013, Denver, Sep. 2013)",
"author_names": [
"Ke Ma"
],
"corpus_id": 195729917,
"doc_id": "195729917",
"n_citations": 134,
"n_key_citations": 5,
"score": 0,
"title": "Thermal \" Loading \" and \" Lifetime \" Estimation \" for \" Power \" Device \" Considering \" Mission \" Profiles \" in \" Wind \" Power \" Converter \"",
"venue": "",
"year": 2014
}
] |
microelectronic circuits and devices | [
{
"abstract": "1. Review of Linear Circuit Theory. Kirchhoff's voltage and current laws. Voltage bus notation. Definition of voltage current characteristic. Superposition in linear circuits. Resistive circuits. Thevenin equivalent circuits. Norton equivalent circuits. Voltage and current division. Single time constant resistor capacitor circuits. 2. Operational Amplifiers. Integrated circuit operational amplifier. Simplified Op amp model. Simplified Op amp model. Ideal Op amp approximation. Linear op amp circuits. Nonlinear operational amplifier circuits. Nonideal properties of operational amplifiers. 3. Introduction to Nonlinear Circuit Elements. Basic properties of nonlinear elements. Graphical analysis with one nonlinear circuit element. Examples of two terminal nonlinear devices. Graphical method with time varying sources. Iterative mathematical solutions. Piecewise linear modeling of two terminal nonlinear devices. 4. Signal Processing and Conditioning with Two terminal Nonlinear Devices. The transfer characteristic. Clipping and limiting circuits. Rectifier circuits. Power supply circuits. Precision rectifier circuits. 5. Three Terminal Devices. Definition of a three terminal device. Field effect transistors. Bipolar junction transistor. Upward slope of transistor V 1 characteristics. Photonic devices. Temperature dependence of devices. Power limitations of device operation. 6. Basic Circuits Containing Three Terminal Devices. Inverter configuration. Voltage follower configuration. Current follower configuration. Operation in the digital regime. 7. Analog Amplification. Definition of a signal. Active and passive circuits. Biasing. Small signal modeling of analog circuits. Two port amplifier representation. 8. Differential Amplifiers. Basic differential amplifier topology. Differential and common mode signals. BJT differential amplifier. MOSFET and JFET differential amplifiers. Large signal performance of differential amplifiers. 9. Frequency Response and Time Dependent Circuit Behavior. Sources of capacitance and inductance in electronic circuits. Sinusoidal steady state amplifier response. Frequency response of circuits containing capacitors. Frequency response of the differential amplifier. Time response of electronic circuits. 10. Feedback and Stability. The negative feedback loop. General requirements of feedback circuits. Effects of feedback on amplifier performance. The four basic amplifier types. The four feedback topologies. Effect of feedback connections on amplifier port resistance. Examples of real feedback amplifiers. Feedback loop stability. 11. Multistage and Power Amplifiers. Input and output loading. Two port amplifier cascade. Multistage amplifier biasing. DC level shifting. Differential amplifier cascade. Power amplification output stages. Integrated circuit power amplifiers. Power devices. 12. Analog Integrated Circuits. Basic operational amplifier cascade. Case Study: The LM741 Bipolar operational amplifier. Case Study: A simple CMOS Operational Amplifier. 13. Active Filters and Oscillators. A simple first order active filter. Ideal filter functions. Second order filter responses. Active filter cascading. Magnitude and frequency scaling. Switched capacitor networks and filters. Oscillators. 14. Digital Circuits. Fundamental concepts of digital circuits. CMOS logic family. NMOS logic family. TTL logic family. Emitter coupled logic family. BiCMOS logic circuits. 15. Fundamentals of Digital Systems. Sequential logic circuits. Multivibrator circuits. Digital memory. Analog to digital interfacing. 16. Electronic Design. An overview of the design process. The tools of electronic design. Open ended design problems. Analog integrated circuit design problems. Appendix A: Physics of Semiconductor Devices. Electronic materials. Qualitative description of holes. Impurities. Carrier densities within a semiconductor. Current flow in a semiconductor. Diffusion gradient within a semiconductor. Derivation of the v i characteristic of the PN junction diode. The bipolar junction transistor. The metal oxide semiconductor field effect transistor. Appendix B: Semiconductor Device and Integrated Circuit Fabrication. An overview of the fabrication process. Epitaxial growth. Oxidation. Wafer doping. Film deposition. Wafer etching. Lithographic processing. A MOS fabrication sequence. A BJT fabrication sequence. Appendix C: Computer Aided Circuit Design Using SPICE and PSpice. Use of SPICE. Capabilities of SPICE and PSPICE. Circuit description. Types of analyses. Generating output. References. Appendix D: Resistor Color Codes and Standard Values. Appendix E: Suggestions for Further Reading. Appendix F: Answers to Selected Problems.",
"author_names": [
"Mark Horenstein"
],
"corpus_id": 62410140,
"doc_id": "62410140",
"n_citations": 68,
"n_key_citations": 1,
"score": 1,
"title": "Microelectronic circuits and devices",
"venue": "",
"year": 1990
},
{
"abstract": "1. Introduction. 2. Power Semiconductor Diodes and Circuits. 3. Diode Rectifiers. 4. Power Transistors. 5. DC DC Converters. 6. Pulse width Modulated Inverters. 7. Thyristors. 8. Resonant Pulse Inverters. 9. Multilevel Inverters. 10. Controlled Rectifiers. 11. AC Voltage Controllers. 12. Static Switches. 13. Flexible AC Transmission Systems. 14. Power Supplies. 15. DC Drives. 16. AC Drives. 17. Gate Drive Circuits. 18. Protection of Devices and Circuits. Appendices: Three phase Circuits, Magnetic Circuits, Switching Functions of Converters, DC Transient Analysis, Fourier Analysis, Thyristor Commutation Techniques, Data Sheets.",
"author_names": [
"M H Rashid"
],
"corpus_id": 108968918,
"doc_id": "108968918",
"n_citations": 2288,
"n_key_citations": 114,
"score": 0,
"title": "Power Electronics: Circuits, Devices and Applications",
"venue": "",
"year": 1993
},
{
"abstract": "MICROELECTRONIC device integration has progressed to the point where complete 'systems on a chip' have been realized1 3. Now that optoelectronics is becoming increasingly important for information and communication technologies, there is a need to develop optoelectronic devices that can be integrated with standard microelectronics. Conventional semiconductor technology is largely based on crystalline silicon, which (being an indirect bandgap semiconductor) is an inefficient light emitting material. This has stimulated significant effort towards developing silicon based optoelectronic components and, of the several strategies explored so far4,5, the use of porous silicon appears the most promising; porous silicon produces high efficiency, room temperature, visible photoluminescence6, and its material and optical properties have been studied in detail7,8. But the extreme reactivity and fragility of porous silicon have hitherto prevented its integration with conventional silicon processing technology. We have recently shown9,10 that the thermal and chemical stability of porous silicon can be greatly enhanced while retaining desirable light emitting and charge transport properties by partial oxidation. Here we take advantage of these improvements in material properties to demonstrate the successful integration of silicon based visible light emitting devices into a standard bipolar microelectronic circuit.",
"author_names": [
"Karl D Hirschman",
"Leonid Tsybeskov",
"Siddhartha P Duttagupta",
"Philippe M Fauchet"
],
"corpus_id": 4332569,
"doc_id": "4332569",
"n_citations": 729,
"n_key_citations": 0,
"score": 0,
"title": "Silicon based visible light emitting devices integrated into microelectronic circuits",
"venue": "Nature",
"year": 1996
},
{
"abstract": "This preview guide presents the first 10 chapters of the our new title by Richard Jaeger: Microelectronic Circuit Design. This cutting edge new text develops a comprehensive understanding of the basic techniques of modern electronic circuit design, analog and digital, discrete and integrated. Digital electronics has evolved to be an extremely important area of circuit design, but it is included almost as an after thought in the majority of introductory electronics texts. This book presents a much more balanced coverage of analog and digital circuits. The writing integrates the author's extensive industrial backround in precision analog and digital design with his many years of experience in the classroom.",
"author_names": [
"Richard C Jaeger",
"Travis N Blalock"
],
"corpus_id": 114754427,
"doc_id": "114754427",
"n_citations": 252,
"n_key_citations": 22,
"score": 0,
"title": "Microelectronic Circuit Design",
"venue": "",
"year": 1996
},
{
"abstract": "Negative mutual inductance results from coupling between two conductors having current vectors in opposite directions. As a quantity in electronic circuits, negative mutual inductance is usually so much smaller in magnitude than overall inductance that it can be neglected with little effect. In the microelectronic world, however, its neglect can result in inductance values as much as 30 percent too high. This paper derives inductance equations for planar thin or thick film coils, comparing equations that include negative mutual inductance with those that do not. It describes a computer program developed for calculating inductances for both square and rectangular geometries, the variables considered being track width, space between tracks, and number of turns. Graphic results are presented for up to 16 turns over an inductance range of 3 nanohenries to 10 microhenries. Although details of fabrication are not included, the effects of film thickness and frequency on the mutual inductance parameter are discussed.",
"author_names": [
"H M Greenhouse"
],
"corpus_id": 109419664,
"doc_id": "109419664",
"n_citations": 978,
"n_key_citations": 56,
"score": 0,
"title": "Design of Planar Rectangular Microelectronic Inductors",
"venue": "",
"year": 1974
},
{
"abstract": "(NOTE: Each chapter concludes with Summary, References, and Problems. Preface. 1. An Overview of Microelectronic Fabrication. A Historical Perspective. An Overview of Monolithic Fabrication Processes and Structures. Metal Oxide Semiconductor (MOS) Processes. Basic Bipolar Processing. Safety. 2. Lithography. The Photolithographic Process. Etching Techniques. Photomask Fabrication. Exposure Systems. Exposure Sources. Optical and Electron Microscopy. Further Reading. 3. Thermal Oxidation of Silicon. The Oxidation Process. Modeling Oxidation. Factors Influencing Oxidation Rate. Dopant Redistribution During Oxidation. Masking Properties of Silicon Dioxide. Technology of Oxidation. Oxide Quality. Selective Oxidation and Shallow Trench Formation. Oxide Thickness Characterization. Process Simulation. 4. Diffusion. The Diffusion Process. Mathematical Model for Diffusion. The Diffusion Coefficient. Successive Diffusions. Solid Solubility Limits. Junction Formation and Characterization. Sheet Resistance. Generation Depth and Impurity Profile Measurement. Diffusion Simulation. Diffusion Systems. Gettering. 5. Ion Implantation. Implantation Technology. Mathematical Model for Ion Implantation. Selective Implantation. Junction Depth and Sheet Resistance. Channeling, Lattice Damage, and Annealing. Shallow Implantation. Source Listing 6. Film Deposition. Evaporation. Sputtering. Chemical Vapor Deposition. Epitaxy. Further Reading. 7. Interconnections and Contacts. Interconnections in Integrated Circuits. Metal Interconnections and Contact Technology. Diffused Interconnections. Polysilicon Interconnections and Buried Contacts. Silicides and Multilayer Contact Technology. The Liftoff Process. Multilevel Metallization. Copper Interconnects and Damascene Processes. Further Reading. 8. Packaging and Yield. Testing. Wafer Thinning and Die Separation. Die Attachment. Wire Bonding. Packages. Flip Chip and Tape Automated Bonding Processes. Yield. Further Reading. 9. MOS Process Integration. Basic MOS Device Considerations. MOS Transistor Layout and Design Rules. Complementary MOS (CMOS) Technology. Silicon on Insulator. 10. Bipolar Process Integration. The Junction Isolated Structure. Current Gain. Transit Time. Basewidth. Breakdown Voltages. Other Elements in SBC Technology. Layout Considerations. Advanced Bipolar Structures. Other Bipolar Isolation Techniques. BICMOS. 11. Processes for Microelectromechanical Systems MEMS. Mechanical Properties of Silicon. Bulk Micromachining. Silicon Etchants. Surface Micromachining. High Aspect Ratio Micromachining: The LIGA Molding Process. Silicon Wafer Bonding. IC Process Compatibility. Answers to Selected Problems. Index.",
"author_names": [
"Richard C Jaeger"
],
"corpus_id": 137270929,
"doc_id": "137270929",
"n_citations": 628,
"n_key_citations": 44,
"score": 0,
"title": "Introduction to microelectronic fabrication",
"venue": "",
"year": 1987
},
{
"abstract": "Random device mismatch plays an important role in the design of accurate analog circuits. Models for the matching of MOS and bipolar devices from open literature show that matching improves with increasing device area. As a result, accuracy requirements impose a minimal device area and this paper explores the impact of this constraint on the performance of general analog circuits. It results in a fixed bandwidth accuracy power tradeoff which is set by technology constants. This tradeoff is independent of bias point for bipolar circuits whereas for MOS circuits some bias point optimizations are possible. The performance limitations imposed by matching are compared to the limits imposed by thermal noise. For MOS circuits the power constraints due to matching are several orders of magnitude higher than for thermal noise. For the bipolar case the constraints due to noise and matching are of comparable order of magnitude. The impact of technology scaling on the conclusions of this work are briefly explored.",
"author_names": [
"Peter R Kinget"
],
"corpus_id": 5995348,
"doc_id": "5995348",
"n_citations": 452,
"n_key_citations": 23,
"score": 0,
"title": "Device mismatch and tradeoffs in the design of analog circuits",
"venue": "IEEE Journal of Solid State Circuits",
"year": 2005
},
{
"abstract": "Present polymeric microelectronic devices are typically unipolar devices, based on p type semiconducting polymers. Bipolar devices stable under ambient conditions are desirable, but have not yet been reported due to a lack of stable n type doped conducting polymers. Starting from the standard redox potentials of, especially, water and oxygen, stability requirements on electrode potentials of n type doped conducting polymers are derived. The predictions are then compared with experimental data on stability of conducting polymers. A good agreement is obtained. An electrode potential of about 0 to 0.5 V (SCE) is required for stable n type doped polymers, similar to the requirement on the electrode potential for stable undoped p type polymers. Consequences for bipolar devices are analysed. Huge overpotentials for the redox reaction with wet oxygen are required in order to realize thermodynamically stable bipolar devices from known doped p type and n type conducting polymers. Finally, possible solutions, accepting thermodynamic instability, are discussed.",
"author_names": [
"Dago M de Leeuw",
"Maurice Maria Johannes Simenon",
"Adam R C Brown",
"R E F Einerhand"
],
"corpus_id": 97359814,
"doc_id": "97359814",
"n_citations": 1095,
"n_key_citations": 5,
"score": 0,
"title": "Stability of n type doped conducting polymers and consequences for polymeric microelectronic devices",
"venue": "",
"year": 1997
},
{
"abstract": "Introduction Plasma and Its Classification Application of Low Temperature Plasma Academic Fusion References Phenomenological Description of the Charged Particle Transport Transport in Real (Configuration) Space Momentum Balance of Electrons Energy Balance of Electrons Transport in Velocity Space Electron Velocity Distribution and Swarm Parameters Ion Velocity Distribution and Mean Energy Thermal Equilibrium and its Governing Relations Boltzmann Distribution in Real Space Maxwell Distribution in Velocity Space References Macroscopic Plasma Characteristics Introduction Quasi Neutrality Charge separation In Plasmas Spatial Scale of Charge Separation Time Scale for Charge Separation Plasma Shielding Debye Shielding Metal Probe in a Plasma Particle Diffusion Ambipolar Diffusion Spatial and Time Scale of Diffusion Bohm Sheath Criterion Bohm Velocity Floating Potential References Elementary Processes in Gas Phase and on Surfaces Particles and Waves Particle Representation in Classical and Quantum Mechanics Locally Isolated Particle Group and Wave Packets Collisions and Cross Sections Conservation Laws in Collisions Definition of Collision Cross Sections The Distribution of Free Paths Representation of Collisions in Laboratory and CM Reference Frames Classical Collision Theory Scattering in Classical Mechanics Conditions for the Applicability of the Classical Scattering Theory Quantum Theory Of Scattering Differential Scattering Cross Section sigma(theta) Modified Effective Range Theory in Electron Scattering Collisions Between Electrons And Neutral Atoms/Molecules Resonant Scattering Electron Atom Collisions Energy Levels of Atoms Electron Atom Scattering Cross Sections Electron Molecule Collisions Rotational, Vibrational, and Electronic Energy Levels of Molecules Rotational Excitation Rotational Energy Levels Rotational Excitation Cross Sections Vibrational Excitation Vibrational Energy Levels Vibrational Cross Sections Electronic Excitation and Dissociation Electronic States of Molecules Cross Sections for Electronic Excitation of Molecules Electron Collisions with Excited Atoms and Molecules Nonconservative Collisions of Electrons With Atoms and Molecules Electron Induced Ionization Electron Attachment Dissociative Electron Attachment Nondissociative Electron Attachment Ion Pair Formation Electron Attachment to Excited Molecules Rate Coefficients for Attachment Electron Ion and Ion Ion Recombination Electron Ion and Electron Electron Collisions Heavy Particle Collisions Ion Molecule Collisions Charge Transfer, Elastic, and Inelastic Scattering of Ions Ion Molecule Reactions Collisions of Fast Neutrals Collisions of Excited Particles Chemi Ionization and Penning Ionization Collisions of Slow Neutrals and Rate Coefficients Quenching and Transport of Excited States Kinetics of Rotational and Vibrational Levels Photons in Ionized Gases Emission and Absorption of Line Radiation Resonant Radiation Trapping Elementary Processes at Surfaces Energy Levels of Electrons in Solids Emission of Electrons from Surfaces Photo Emission Thermionic Emission Field Induced Emission Potential Ejection of Electrons from Surfaces by Ions and Excited Atoms Emission of Ions and Neutrals from Surfaces Surface Neutralization Surface Ionization Adsorption References The Boltzmann Equation and Transport Equations of Charged Particles Introduction The Boltzmann Equation Transport in Phase Space and Derivation of the Boltzmann Equation Transport Coefficients The Transport Equation Conservation of Number Density Conservation of Momentum Conservation of Energy Collision Term In The Boltzmann Equation Collision Integral Collision Integral between an Electron and a Gas Molecule Elastic Collision Term Jelas Excitation Collision Term Jex Ionization Collision Term Jion Electron Attachment Collision Term Jatt Boltzmann Equation For Electrons Spherical Harmonics and Their Properties Velocity Distribution of Electrons Velocity Distribution under Uniform Number Density: g0 Velocity Distribution Proportional to rn(r, t) g1 Electron Transport Parameters References General Properties of Charged Particle Transport in Gases Introduction Electron Transport In DC Electric Fields Electron Drift Velocity Diffusion Coefficients Mean Energy of Electrons Excitation, Ionization, and Electron Attachment Rates Electron Transport in Radio Frequency Electric Fields Relaxation Time Constants Effective Field Approximation Expansion Procedure Direct Numerical Procedure Time Varying Swarm Parameters Ion Transport In Dc Electric Fields References Modeling of Nonequilibrium (Low Temperature) Plasmas Introduction Continuum Models Governing Equations of a Continuum Model Local Field Approximation (LFA) Quasi Thermal Equilibrium (QTE) Model Relaxation Continuum (RCT) Model Phase Space Kinetic Model Particle Models Monte Carlo Simulations (MCSs) Particle in Cell (PIC) and Particle in Cell/Monte Carlo Simulation (PIC/MCS) Models Hybrid Models Circuit Model Equivalent Circuit Model in CCP Equivalent Circuit Model in ICP Transmission Line Model (TLM) Electromagnetic Fields and Maxwell's Equations Coulomb's Law, Gauss's Law, and Poisson's Equation Faraday's Law Ampere's Law Maxwell's Equations References Numerical Procedure of Modeling Time Constant of the System Collision Oriented Relaxation Time Plasma Species Oriented Time Constant Plasma Oriented Time Constant/Dielectric Relaxation Time Numerical Techniques To Solve The Time Dependent Drift Diffusion Equation Time Evolution Method Finite Difference Digitalization and Stabilization Time Discretization and Accuracy Scharfetter Gummel Method Cubic Interpolated Pseudoparticle Method Semi Implicit Method for Solving Poisson's Equation Boundary Conditions Ideal Boundary Without Surface Interactions Dirichlet Condition Neumann Condition Periodicity Condition Electrode Surface Metallic Electrode Dielectric Electrode Boundary Conditions with Charge Exchange Boundary Conditions with Mass Transport Plasma Etching Plasma Deposition Plasma Sputtering Moving Boundary under Processing References Capacitively Coupled Plasma Radio Frequency Capacitive Coupling Mechanism of Plasma Maintenance Low Frequency Plasma High Frequency Plasma Electronegative Plasma Very High Frequency Plasma Two Frequency Plasma Pulsed Two Frequency Plasma References Inductively Coupled Plasma Radio Frequency Inductive Coupling Mechanism of Plasma Maintenance E mode and H mode Mechanism of Plasma Maintenance Effect of Metastables Function of ICP Phase Transition Between E Mode and H Mode in an ICP Wave Propagation in Plasmas Plasma and Skin Depth ICP and the Skin Depth References Magnetically Enhanced Plasma Direct Current Magnetron Plasma Unbalanced Magnetron Plasma Radio Frequency Magnetron Plasma Magnetic Confinements Of Plasmas Magnetically Resonant Plasmas References Plasma Processing and Related Topics Introduction Physical Sputtering Target Erosion Sputtered Particle Transport Plasma Chemical Vapor Deposition Plasma CVD Large Area Deposition with High Rate Plasma Etching Wafer Bias On Electrically Isolated Wafers (without Radio Frequency Bias) On Wafers with Radio Frequency Bias Selection of Feed Gas Si or Poly Si Etching Al Etching SiO2 Etching Feature Profile Evolution Plasma Bosch Process Charging Damage Surface Continuity and Conductivity Charging Damage to Lower Thin Elements in ULSI Thermal Damage Specific Fabrication of MOS Transistor Gate Etching Contact Hole Etching Low K Etching MEMS Fabrication References Atmospheric Pressure, Low Temperature Plasma High Pressure, Low Temperature Plasma Fundamental Process Historical Development Micro Plasma Radiofrequency Atmospheric Micro Plasma Source Gas Heating in a Plasma Effect of Local Gas Heating References Index",
"author_names": [
"Toshiaki Makabe",
"Zoran Lj Petrovic"
],
"corpus_id": 93365384,
"doc_id": "93365384",
"n_citations": 216,
"n_key_citations": 11,
"score": 0,
"title": "Plasma Electronics: Applications in Microelectronic Device Fabrication",
"venue": "",
"year": 2006
},
{
"abstract": "Total ionizing dose radiation effects on the electrical properties of metal oxide semiconductor devices and integrated circuits are complex in nature and have changed much during decades of device evolution. These effects are caused by radiation induced charge buildup in oxide and interfacial regions. This paper presents an overview of these radiation induced effects, their dependencies, and the many different approaches to their mitigation.",
"author_names": [
"Harold L Hughes",
"J M Benedetto"
],
"corpus_id": 111045659,
"doc_id": "111045659",
"n_citations": 251,
"n_key_citations": 7,
"score": 0,
"title": "Radiation effects and hardening of MOS technology: devices and circuits",
"venue": "",
"year": 2003
}
] |
MOSFET models for VLSI circuit simulation: theory and practice | [
{
"abstract": "This study discusses MOS transistor models and their parameters required for VLSI simulation of MOS integrated circuits. It gives detailed presentation of model parameter determination for MOS models. Various models are developed ranging from simple to more sophisticated models that take into account new physical effects observed in submicron devices used in today's MOS VLSI technology. The assumptions used to arrive at the models are emphasized so that the accuracy of the model in describing the device characteristics are clearly understood. Understanding these models is essential when designing circuits for the state of the art MOS ICs. Since threshold voltage is the single most important MOSFET parameter, a full chapter is devoted to the development of the device threshold voltage model. Due to the importance of designing reliable circuits, the device reliability models, as applied for circuit simulations, are also covered. Since the device parameters vary due to inherent processing variations, how to arrive at worst case design parameters are also covered. Presentation of the material is such that even an undergraduate student, not well familiar with semiconductor device physics, can understand the intricacies of MOSFET modeling. The book serves as a technical source in the area of MOSFET modeling for state of the art MOSFET technology for both practicing device and circuit engineers, and engineering students interested in the area.",
"author_names": [
"Narain D Arora"
],
"corpus_id": 108030443,
"doc_id": "108030443",
"n_citations": 307,
"n_key_citations": 21,
"score": 1,
"title": "MOSFET Models for VLSI Circuit Simulation: Theory and Practice",
"venue": "",
"year": 1993
},
{
"abstract": "Overview Review of Basic Semiconductor and pn Junction Theory MOS Transistor Structure and Operation MOS Capacitor Threshold Voltage MOSFET DC Model Dynamic Model Modeling Hot Carrier Effects Data Acquisition and Model Parameter Measurements Model Parameter Extraction Using Optimization Method SPICE Diode and MOSFET Models and Their Parameters Statistical Modeling and Worst Case Design Parameters.",
"author_names": [
"Narain D Arora"
],
"corpus_id": 41571452,
"doc_id": "41571452",
"n_citations": 162,
"n_key_citations": 13,
"score": 0,
"title": "MOSFET Modeling for VLSI Simulation Theory and Practice",
"venue": "International Series on Advances in Solid State Electronics and Technology",
"year": 2007
},
{
"abstract": "For both introductory and advanced courses in VLSI design, this authoritative, comprehensive textbook is highly accessible to beginners, yet offers unparalleled breadth and depth for more experienced readers. The Fourth Edition of CMOS VLSI Design: A Circuits and Systems perspective presents broad and in depth coverage of the entire field of modern CMOS VLSI Design. The authors draw upon extensive industry and classroom experience to introduce todays most advanced and effective chip design practices. They present extensively updated coverage of every key element of VLSI design, and illuminate the latest design challenges with 65 nm process examples. This book contains unsurpassed circuit level coverage, as well as a rich set of problems and worked examples that provide deep practical insight to readers at all levels.",
"author_names": [
"Neil Weste",
"D Harris"
],
"corpus_id": 108665214,
"doc_id": "108665214",
"n_citations": 2360,
"n_key_citations": 293,
"score": 0,
"title": "CMOS VLSI Design: A Circuits and Systems Perspective",
"venue": "",
"year": 2004
},
{
"abstract": "This book presents a unified view of MOSFET modeling, allowing the practitioner to view and interpret device phenomena concurrently using different modeling strategies, as opposed to gaining familiarity with the models in isolation. Secondly, while MOS devices are well covered in a number of text books, device physics do not get necessarily linked to model parameters which serve as an input in design phase, leaving a wide gap between device understanding and its use for optimal circuit performance. Further, being technology driven, models undergo evolution continuously. Yet from the projection of International Technology Roadmap for Semiconductors (ITRS) it is possible to identify the core physical concepts that will drive the evolution and trend that is likely to dominate the future. Therefore, the impact of quantum mechanical related phenomena has been given more prominent presence in the pedagogic approach of this book than is available in currently available texts.Uses a unified approach to coach students through the confusing array of MOSFET models One of the first books to relate MOS physics with device models to better prepare practitioners for real world design activities Helps fables designers bridge the gap with off site foundries Presents topics that will prepare readers for long term developments in the field Includes solutions in every chapter Can be tailored for use among students and professionals of many levels Comes with MATLAB code downloads for independent practice and advanced study Includes presentation slides with book figures for lecturer use",
"author_names": [
"A B Bhattacharyya"
],
"corpus_id": 106465525,
"doc_id": "106465525",
"n_citations": 78,
"n_key_citations": 7,
"score": 0,
"title": "Compact MOSFET Models for VLSI Design",
"venue": "",
"year": 2009
},
{
"abstract": "This paper presents a systematic methodology to develop statistical compact MOS models for advanced VLSI circuit simulation. Process variability in advanced CMOS technologies imposes a serious challenge for computer aided VLSI circuit design. Therefore, statistical compact model has become indispensable for realistic assessment of the impact of random process variability on advanced VLSI circuit performance. This paper describes the major parameter set causing local and global process variability in nanoscale CMOS devices and presents a methodology to generate simplified statistical compact MOS models for VLSI circuit simulation.",
"author_names": [
"Samar K Saha"
],
"corpus_id": 35380528,
"doc_id": "35380528",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Process Variability Modeling for VLSI Circuit Simulation",
"venue": "",
"year": 2011
},
{
"abstract": "(NOTE: Chapters 3 11 include an Introduction, Historical Development and Basic Concepts, Manufacturing Methods and Equipment, Measurement Methods, Models and Simulation, Limits and Future Trends in Technologies and Models, Summary of Key Ideas, References, and Problems. 1. Introduction and Historical Perspective. Introduction. Integrated Circuits and the Planar Process Key Inventions That Made It All Possible. Semiconductors. Semiconductor Devices. Semiconductor Circuit Families. Modern Scientific Discovery Experiments, Theory and Computer Simulation. The Plan for This Book. 2. Modern CMOS Technology. CMOS Process Flow. 3. Crystal Growth, Wafer Fabrication and Basic Properties of Silicon Wafers. 4. Semiconductor Manufacturing Clean Rooms, Wafer Cleaning and Gettering. 5. Lithography. 6. Thermal Oxidation and the Si/SiO2 Interface. 7. Dopant Diffusion. 8. Ion Implantation. 9. Thin Film Deposition. 10. Etching. 11. Backend Technology.",
"author_names": [
"James D Plummer",
"Michael D Deal",
"Peter B Griffin"
],
"corpus_id": 107363121,
"doc_id": "107363121",
"n_citations": 66,
"n_key_citations": 11,
"score": 0,
"title": "Silicon VLSI Technology: Fundamentals, Practice, and Modeling",
"venue": "",
"year": 2020
},
{
"abstract": "The Third Edition of CMOS Circuit Design, Layout, and Simulation continues to cover the practical design of both analog and digital integrated circuits, offering a vital, contemporary view of a wide range of analog/digital circuit blocks including: phase locked loops, delta sigma sensing circuits, voltage/current references, op amps, the design of data converters, and much more. Regardless of one's integrated circuit (IC) design skill level, this book allows readers to experience both the theory behind, and the hands on implementation of, complementary metal oxide semiconductor (CMOS) IC design via detailed derivations, discussions, and hundreds of design, layout, and simulation examples.",
"author_names": [
"R J Baker"
],
"corpus_id": 60745513,
"doc_id": "60745513",
"n_citations": 2776,
"n_key_citations": 243,
"score": 0,
"title": "CMOS Circuit Design, Layout, and Simulation",
"venue": "",
"year": 1997
},
{
"abstract": "An alpha power law MOS model that includes the carrier velocity saturation effect, which becomes prominent in short channel MOSFETs, is introduced. The model is an extension of Shockley's square law MOS model in the saturation region. Since the model is simple, it can be used to handle MOSFET circuits analytically and can predict the circuit behavior in the submicrometer region. Using the model, closed form expressions for the delay, short circuit power, and transition voltage of CMOS inverters are derived. The delay expression includes input waveform slope effects and parasitic drain/source resistance effects and can be used in simulation and/or optimization CAD tools. It is found that the CMOS inverter delay becomes less sensitive to the input waveform slope and that short circuit dissipation increases as the carrier velocity saturation effect in short channel MOSFETs gets more severe.",
"author_names": [
"Takayasu Sakurai",
"A Richard Newton"
],
"corpus_id": 40826231,
"doc_id": "40826231",
"n_citations": 1244,
"n_key_citations": 86,
"score": 0,
"title": "Alpha power law MOSFET model and its applications to CMOS inverter delay and other formulas",
"venue": "",
"year": 1990
},
{
"abstract": "",
"author_names": [
"H B Bakoglu"
],
"corpus_id": 60602878,
"doc_id": "60602878",
"n_citations": 1931,
"n_key_citations": 137,
"score": 0,
"title": "Circuits, interconnections, and packaging for VLSI",
"venue": "",
"year": 1990
},
{
"abstract": "The problem of achieving compact, high performance forced liquid cooling of planar integrated circuits has been investigated. The convective heat transfer coefficient h between the substrate and the coolant was found to be the primary impediment to achieving low thermal resistance. For laminar flow in confined channels, h scales inversely with channel width, making microscopic channels desirable. The coolant viscosity determines the minimum practical channel width. The use of high aspect ratio channels to increase surface area will, to an extent, further reduce thermal resistance. Based on these considerations, a new, very compact, water cooled integral heat sink for silicon integrated circuits has been designed and tested. At a power density of 790 W/cm2, a maximum substrate temperature rise of 71degC above the input water temperature was measured, in good agreement with theory. By allowing such high power densities, the heat sink may greatly enhance the feasibility of ultrahigh speed VLSI circuits.",
"author_names": [
"David B Tuckerman",
"R F W Pease"
],
"corpus_id": 40590765,
"doc_id": "40590765",
"n_citations": 3528,
"n_key_citations": 181,
"score": 0,
"title": "High performance heat sinking for VLSI",
"venue": "IEEE Electron Device Letters",
"year": 1981
}
] |
AM FM music synthesis | [
{
"abstract": "There are many techniques currently used for digital music synthesis, including frequency modulation (FM) synthesis, waveshaping, additive synthesis, and subtractive synthesis. To achieve rich, natural sounds, all of them require fast arithmetic capability, such as is found on expensive computers or digital synthesizers. For musicians and experimenters without access to these machines, musically interesting digital synthesis has been almost impossible. The techniques described in this paper can be implemented quite cheaply on almost any computer. Real time synthesis implementations have been done for Intel 8080A (by Alex Strong) Texas Instruments TMS9900 (by Kevin Karplus) and SC/MP (by Mike Plass) microprocessors. David Jaffe and Julius Smith have programmed the Systems Concept Digital Synthesizer at the Center for Computer Research in Music and Acoustics (CCRMA) to perform several variants of the algorithms (Jaffe and Smith 1983) Not only are the algorithms simple to implement in software, but hardware realizations are easily done. The authors have designed and tested a custom n channel metal oxide semiconductor (nMOS) chip (the Digitar chip) which computes 16 independent notes, each with a sampling rate of 20 KHz.",
"author_names": [
"Kevin Karplus",
"Alexander R Strong"
],
"corpus_id": 62673685,
"doc_id": "62673685",
"n_citations": 337,
"n_key_citations": 11,
"score": 1,
"title": "Digital Synthesis of Plucked String and Drum Timbers",
"venue": "",
"year": 1983
},
{
"abstract": "Created in 1985 by Barry Vercoe, Csound is one of the most widely used software sound synthesis systems. Because it is so powerful, mastering Csound can take a good deal of time and effort. But this long awaited guide will dramatically straighten the learning curve and enable musicians to take advantage of this rich computer technology available for creating music. Written by the world's leading educators, programmers, sound designers, and composers, this comprehensive guide covers both the basics of Csound and the theoretical and musical concepts necessary to use the program effectively. The thirty two tutorial chapters cover: additive, subtractive, FM, AM, FOF, granular, wavetable, waveguide, vector, LA, and other hybrid methods; analysis and resynthesis using ADSYN, LP, and the Phase Vocoder; sample processing; mathematical and physical modeling; and digital signal processing, including room simulation and 3D modeling. Supplemental Content is now available for download at http:/mitpress.mit.edu/9780262522618",
"author_names": [
"Richard Boulanger"
],
"corpus_id": 60038525,
"doc_id": "60038525",
"n_citations": 153,
"n_key_citations": 21,
"score": 0,
"title": "The Csound book: perspectives in software synthesis, sound design, signal processing, and programming",
"venue": "",
"year": 2000
},
{
"abstract": "In this paper, the AM FM modulation model is applied to speech analysis, synthesis and coding. The AM FM model represents the speech signal as the sum of formant resonance signals each of which contains amplitude and frequency modulation. Multiband filtering and demodulation using the energy separation algorithm are the basic tools used for speech analysis. First, multiband demodulation analysis (MDA) is applied to the problem of fundamental frequency estimation using the average instantaneous frequency as estimates of pitch harmonics. The MDA pitch tracking algorithm is shown to produce smooth and accurate fundamental frequency contours. Next, the AM FM modulation vocoder is introduced, which represents speech as the sum of resonance signals. A time varying filterbank is used to extract the formant bands and then the energy separation algorithm is used to demodulate the resonance signals into the amplitude envelope and instantaneous frequency signals. EAcient modeling and coding (at 4.8 9.6 kbits/sec) algorithms are proposed for the amplitude envelope and instantaneous frequency of speech resonances. Finally, the perceptual importance of modulations in speech resonances is investigated and it is shown that amplitude modulation patterns are both speaker and phone dependent. \" 1999 Elsevier Science B.V. All rights reserved. Zusammenfassung",
"author_names": [
"Alexandros Potamianos",
"Petros Maragos"
],
"corpus_id": 5994224,
"doc_id": "5994224",
"n_citations": 83,
"n_key_citations": 0,
"score": 0,
"title": "Speech analysis and synthesis using an AM FM modulation model",
"venue": "Speech Commun.",
"year": 1999
},
{
"abstract": "Vocoders received renewed attention recently as basic components in speech synthesis applications such as voice transformation, voice conversion and statistical parametric speech synthesis. This paper presents a new vocoder synthesizer, referred to as Vocaine, that features a novel Amplitude Modulated Frequency Modulated (AM FM) speech model, a new way to synthesize non stationary sinusoids using quadratic phase splines and a super fast cosine generator. Extensive evaluations are made against several state of the art methods in Copy Synthesis and Text To Speech synthesis experiments. Vocaine matches or outperforms STRAIGHT in Copy Synthesis experiments and outperforms our baseline real time optimized Mixed Excitation vocoder with the same computational cost. We report that Vocaine considerably improves our statistical TTS synthesizers and that our new statistical parametric synthesizer [1] matched the quality of our mature production Unit Selection system with uncompressed waveforms.",
"author_names": [
"Yannis Agiomyrgiannakis"
],
"corpus_id": 218221,
"doc_id": "218221",
"n_citations": 67,
"n_key_citations": 8,
"score": 0,
"title": "Vocaine the vocoder and applications in speech synthesis",
"venue": "2015 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)",
"year": 2015
},
{
"abstract": "Digital synthesis of music has led to the consideration of models other than the usual additive (Fourier) synthesis of waveforms. One of these methods, based on the FM equation, has been found to be of particular value due to its easy implementation and the richness and evolutionary character of its harmonic structure in time. Any useful synthesis procedure should be accompanied by a corresponding analytic procedure. In this paper we lay the foundations for such a procedure based on the discrete Hilbert transform.",
"author_names": [
"James H Justice"
],
"corpus_id": 123406560,
"doc_id": "123406560",
"n_citations": 42,
"n_key_citations": 3,
"score": 0,
"title": "Analytic signal processing in music computation",
"venue": "",
"year": 1979
},
{
"abstract": "BACKGROUND Ligustilide is a bioactive phthalide derivative isolated from Cnidii Rhizoma (Cnidium officinale, rhizome) and Angelicae Gigantis Radix (Angelica gigas Nakai, root) which are both medicinal herbs used to treat circulatory disorders. Vascular endothelium is a central spot in developing cardiovascular diseases and chronic vascular inflammation might result in atherosclerosis development. PURPOSE We previously found out that a traditional herbal formula, Samul Tang (Si Wu Tang, containing Cnidii Rhizoma and Angelicae Gigantis Radix) attenuated vascular inflammation in human umbilical vein endothelial cells (HUVECs) However, which compound was responsible for vascular protective action remained unclear. Here, we investigated vascular protective potential of an isolated single compound, (Z) ligustilide. METHODS MTT assay, western blotting, immunofluorescence, electrophoretic mobility shift assay was performed. BCECF AM, CM H2DCFDA, DAF FM diacetate were used as a fluorescent indicator. RESULTS Ligustilide suppressed HL 60 monocyte adhesion and CAMs (ICAM 1, VCAM 1, E selectin) expression in HUVECs. Ligustilide significantly inhibited TNF a increased production of ROS and activated NF kB signaling pathway. Also, ligustilide treated HUVECs exhibited significant HO 1 induction via Nrf2 nuclear translocation and endothelial NO synthesis. CONCLUSION Present study demonstrates that ligustilde attenuates vascular inflammation and activate defense system of endothelial cell. Ligustilide is a bioactive compound which might prevent cardiovascular complications such as thrombosis or atherosclerosis.",
"author_names": [
"Eun Sik Choi",
"Jung Joo Yoon",
"Byung Hyuk Han",
"Da Hye Jeong",
"Yun Jung Lee",
"Dae Gill Kang",
"Ho Sub Lee"
],
"corpus_id": 46777540,
"doc_id": "46777540",
"n_citations": 39,
"n_key_citations": 2,
"score": 0,
"title": "Ligustilide attenuates vascular inflammation and activates Nrf2/HO 1 induction and, NO synthesis in HUVECs.",
"venue": "Phytomedicine international journal of phytotherapy and phytopharmacology",
"year": 2018
},
{
"abstract": "Granular synthesis has been used for a number of years as a sound synthesis technique. This method constructs an acoustic signal from a number of short duration acoustic elements, called grains. These grains are produced either by extracting short segments of natural sounds such as speech, or by synthesis according to a mathematical description of the grains. Efficient methods of producing and combining these grains are currently especially interesting, because the recent development of special purpose digital signal processing (DSP) microprocessors has made real time granular synthesis possible at a reasonable hardware cost. This paper discusses the computational aspects of granular synthesis. Methods of extracting grains from natural signals and recombining them with phase alignment are described. Fast methods for digital generation of synthetic signals with linear frequency modulation (FM) are also presented.",
"author_names": [
"Douglas L Jones",
"Thomas W Parks"
],
"corpus_id": 62745266,
"doc_id": "62745266",
"n_citations": 29,
"n_key_citations": 1,
"score": 0,
"title": "GENERATION AND COMBINATION OF GRAINS FOR MUSIC SYNTHESIS.",
"venue": "",
"year": 1988
},
{
"abstract": "Analysis and Synthesis of Musical Instrument Sounds: Analysis/Synthesis Methods.Analysis Results using SNDAN.Summary. Fundamental Frequency Tracking and Applications to Music Signal Analysis: Introduction to Musical Signal Analysis in the Frequency Domain.Calculation of a Constant Q Transform for Musical Analysis.Musical Fundamental Frequency Tracking using a Pattern Recognition Method.High Resolution Frequency Calculation Based on Phase Differences.Applications of the High Resolution Pitch Tracker.Summary and Conclusions. Beyond Traditional Sampling Synthesis: Real Time Timbre Morphing using Additive Synthesis: Introduction.Additive Synthesis Model.Additive Sound Analysis.Navigating Source Timbres: Timbre Control Space.New Possibilities for the Performer: the Continuum Fingerboard.Final Summary. A Compact and Malleable Sines Transients Noise Model for Sound: Introduction.System Overview.Multi Resolution Sinusoidal Modeling.Transform Cided Transients.Noise Modeling.Applications.Conclusions.Acknowledgement. Spectral Envelopes and Additive Residual Analysis/Synthesis: Introduction.Spectral Envelopes and Source Filter Models.Spectral Envelope Estimation Methods.Representation of Spectral Envelopes.Transcoding and Manipulation of Spectral Envelopes.Synthesis with Spectral Envelopes.Applications.Conclusions.Summary. A Comparison of Wavetable and FM Data Reduction Methods for Resynthesis of Musical Sounds: Introduction.Evaluation of Wavetable and FM Methods.Comparison of Wavetable and FM Methods.Results.Conclusions. The Effect of Dynamic Acoustical Features on Musical Timbre: Introduction.Global Time Envelope and Spectral Parameters.The Experimental Control of Acoustical Variables.Conclusions and Directions for Future Research. Mental Representation of the Timbre of Complex Sounds: Timbre: A Problematic Definition.The Notion of Timbre Space.Categories of Timbre.Conclusions.",
"author_names": [
"James W Beauchamp"
],
"corpus_id": 62336288,
"doc_id": "62336288",
"n_citations": 23,
"n_key_citations": 0,
"score": 0,
"title": "Analysis, Synthesis, and Perception of Musical Sounds: The Sound of Music (Modern Acoustics and Signal Processing)",
"venue": "",
"year": 2006
},
{
"abstract": "This paper introduces a general and flexible framework for F0 and aperiodicity (additive non periodic component) analysis, specifically intended for high quality speech synthesis and modification applications. The proposed framework consists of three subsystems: instantaneous frequency estimator and initial aperiodicity detector, F0 trajectory tracker, and F0 refinement and aperiodicity extractor. A preliminary implementation of the proposed framework substantially outperformed (by a factor of 10 in terms of RMS F0 estimation error) existing F0 extractors in tracking ability of temporally varying F0 trajectories. The front end aperiodicity detector consists of a complex valued wavelet analysis filter with a highly selective temporal and spectral envelope. This front end aperiodicity detector uses a new measure that quantifies the deviation from periodicity. The measure is less sensitive to slow FM and AM and closely correlates with the signal to noise ratio.",
"author_names": [
"Hideki Kawahara",
"Yannis Agiomyrgiannakis",
"Heiga Zen"
],
"corpus_id": 32225,
"doc_id": "32225",
"n_citations": 21,
"n_key_citations": 6,
"score": 0,
"title": "Using instantaneous frequency and aperiodicity detection to estimate F0 for high quality speech synthesis",
"venue": "SSW",
"year": 2016
},
{
"abstract": "Herein, an ultrasensitive and label free electrochemical biosensor was developed for microRNA (miRNA) based on rolling circle amplification (RCA) mediated palladium nanoparticles (PdNPs) The sensor was fabricated by immobilizing dual functionalized hairpin probes onto an electrode. The specific recognition of target miRNA 21 by the hairpin probes could trigger the RCA reaction, which produced numerous guanine (G) rich long single stranded DNAs (ssDNAs) Based on the interaction of the PdII species with the nitrogen atoms of the G bases, these G rich long ssDNAs served as specific templates in the in situ synthesis of massive PdNPs as electrochemical indicators. The formation of PdNPs was demonstrated to be exactly along the RCA products by high resolution transmission electron microscopy. Using this cascade signal amplification strategy, the developed biosensor achieved a linear range of 50 aM 100 fM with an ultralow detection limit of 8.6 aM miRNA 21. Furthermore, the developed biosensor exhibited good selectivity, reproducibility, stability and satisfactory feasibility for miRNA 21 detection in human serum samples; this ensured significant potential of this biosensor in disease diagnosis and prognosis applications.",
"author_names": [
"Cuiling Zhang",
"Dan Li",
"Dongwei Li",
"Kai Wen",
"Xingdong Yang",
"Ye Zhu"
],
"corpus_id": 149609845,
"doc_id": "149609845",
"n_citations": 16,
"n_key_citations": 0,
"score": 0,
"title": "Rolling circle amplification mediated in situ synthesis of palladium nanoparticles for the ultrasensitive electrochemical detection of microRNA.",
"venue": "The Analyst",
"year": 2019
}
] |
Reliability of power cycling for IGBT power semiconductor modules | [
{
"abstract": "Power cycling capability is one of the most important reliability items in application semiconductor modules. This paper describes the mechanism of power cycling by analysis of the structure of lead based solder and joint failure due to fatigue was studied to ascertain improvement in the power cycling lifetime. Lead based solder has a relatively weaker yield strength which means that plastic deformation leads to deterioration. Therefore, tin silver based solder was selected as a higher yield strength material, and a new composition which has both excellent mechanical properties and wettability was developed. Concerning the failure mechanism of power cycling for this newly developed solder material, solder joint failure and aluminum wire bond failure were clearly distinguished, and the lifetime prediction curve was clarified by FEM analysis and detailed failure analysis. Furthermore, it was proved that the deterioration of new tin silver based solder is caused by thermal fatigue with the grain growth of tin. Thus, longer power cycling capability is achieved by using this newly developed solder instead of conventional lead based solder.",
"author_names": [
"Akira Morozumi",
"K Yamada",
"T Miyasaka",
"Yoshio Seki"
],
"corpus_id": 16907218,
"doc_id": "16907218",
"n_citations": 208,
"n_key_citations": 5,
"score": 1,
"title": "Reliability of power cycling for IGBT power semiconductor modules",
"venue": "Conference Record of the 2001 IEEE Industry Applications Conference. 36th IAS Annual Meeting (Cat. No.01CH37248)",
"year": 2001
},
{
"abstract": "High thermal and electrical stress, over a period of time tends to deteriorate the health of power electronic switches. Being a key element in any high power converter systems, power switches, such as insulated gate bipolar junction transistors (IGBTs) and metal oxide semiconductor field effect transistors, are constantly monitored to predict when and how they might fail. A huge fraction of research efforts involves the study of power electronic device reliability and development of novel techniques with higher accuracy in the health estimation of such devices. Until today, no other existing technique can determine the number of lifted bond wires and their locations in a live IGBT module, although this information is extremely helpful to understand the overall state of health of an IGBT power module. Through this article, a new method for online condition monitoring of IGBTs and IGBT modules using spread spectrum time domain reflectometry has been proposed. Unlike traditional methods, this research work concentrates at the gate terminals (low voltage) of the device instead of looking at the collector side. In addition, the RL equivalent circuit to represent a bond wire has been developed for the device under test and simulated in CST Studio Suite to measure the reflection amplitudes. Experimental results were obtained using a prototype reflectometry hardware, and both the simulation and experimental results have been compared. These results prove that a single measurement is sufficient to predict the failure of the device instead of looking at the traditional precursor parameter (VCEON) With only two sets of measurements, it is possible to locate the aged device inside a module and detect the number of bond wire liftoffs associated with that device.",
"author_names": [
"Abu Hanif",
"Douglas DeVoto",
"Faisal Khan"
],
"corpus_id": 213754702,
"doc_id": "213754702",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Bond Wire Damage Detection and SOH Estimation of a Dual Pack IGBT Power Module Using Active Power Cycling and Reflectometry",
"venue": "IEEE Transactions on Power Electronics",
"year": 2020
},
{
"abstract": "Applications under extreme conditions, such as solid circuit breakers and electromagnetic launching systems, are great challenges to semiconductor power devices. The die attach solder joint is as one of the most vulnerable structures and critical to the reliability of insulated gate bipolar transistor (IGBT) modules. In this paper, IGBT modules were cross sectioned and tested under pulse high current power cycling. The failure mechanism of the die attach solder in IGBTs at pulse high current modes was investigated. Evolution of microdefects in the die attach solder during power cycling was characterized and factors for the failure of die attach solder joints was discussed. The results revealed that voids, cracks, and detachment of interface were the major microdefects in the die attach solder layer. A detachment of the Si/Sn Ag Cu (SAC) interface is verified as the major failure mode under pulse high current power cycling. Interface cracks between the Si chip and die attach solder layer were found to initiate first at the solder layer edges and then extended to the center of the solder layer with the increase of power cycles. The detachment of Si/SAC interface was more similar to the brittle fracture. The junction temperature swing and heating rate were the key factors for detachment of the Si/SAC interface.",
"author_names": [
"Yongle Huang",
"Yifei Luo",
"Fei Xiao",
"Binli Liu"
],
"corpus_id": 61806808,
"doc_id": "61806808",
"n_citations": 20,
"n_key_citations": 0,
"score": 0,
"title": "Failure Mechanism of Die Attach Solder Joints in IGBT Modules Under Pulse High Current Power Cycling",
"venue": "IEEE Journal of Emerging and Selected Topics in Power Electronics",
"year": 2019
},
{
"abstract": "High thermal and electrical stress, over a period of time tends to deteriorate the health of power electronic switches. Being a key element in any high power converter systems, power switches such as Insulated Gate Bipolar Junction Transistors (IGBTs) and Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) are constantly monitored to predict when and how they might fail. A huge fraction of research efforts involves the study of power electronic device reliability and development of novel techniques with higher accuracy in health estimation of such devices. Through this paper, a new method for online condition monitoring of IGBTs and IGBT modules using spread spectrum time domain reflectometry (SSTDR) has been proposed. Unlike traditional methods, this research work concentrates at the gate terminals (low voltage) of the device instead of looking at the collector side. The IGBT collector emitter ON voltage or VCEON was chosen as the failure precursor parameter as the reference, and the auto correlated magnitudes of the SSTDR signal for the new and the aged IGBTs were plotted and compared.",
"author_names": [
"Abu Hanif",
"Swagato Das",
"Faisal Khan"
],
"corpus_id": 5040184,
"doc_id": "5040184",
"n_citations": 12,
"n_key_citations": 0,
"score": 0,
"title": "Active power cycling and condition monitoring of IGBT power modules using reflectometry",
"venue": "2018 IEEE Applied Power Electronics Conference and Exposition (APEC)",
"year": 2018
},
{
"abstract": "A power cycling test bench is realized for the lifetime analysis of IGBT power modules and for the development of a reliability management system predicting the deterioration of the devices. The focus is on converters for doubly fed induction generators used in wind turbines. In these applications, due to the low frequent power losses under steady state conditions and due to changing wind conditions, the thermomechanical stress on IGBT power modules is high. The presented test bench offers accelerated ageing of the power semiconductor devices under real load conditions with the phase legs operating from a 1070VDC dc link allowing sinusoidal load currents up to 800A amplitude at frequencies from 0.1Hz to 13Hz.",
"author_names": [
"Dennis Wagenitz",
"Andre Westerholz",
"Eike Erdmann",
"Andreas Hambrecht",
"Sibylle Dieckerhoff"
],
"corpus_id": 14585879,
"doc_id": "14585879",
"n_citations": 11,
"n_key_citations": 0,
"score": 0,
"title": "Power cycling test bench for IGBT power modules used in wind applications",
"venue": "Proceedings of the 2011 14th European Conference on Power Electronics and Applications",
"year": 2011
},
{
"abstract": "This paper presents a numerical analysis of the temperature profiles within the semiconductor devices of modular multilevel converters (MMCs) These temperature profiles are essential for assessing the power cycling lifetime of IGBT modules, which influences the converter reliability. An electro thermal simulation model has been established, combining a dynamic thermal model of the semiconductor devices with a detailed model of the MMC topology and its associated control loops. Conduction losses and switching losses in the semiconductors are calculated online in the simulation, using the instantaneous voltages and currents in the devices. The presented simulation results reveal low losses and limited thermal stresses in terms of peak to peak temperature variations in the devices, for both a 200 level MMC operating under staircase modulation, as well as for a 20 level MMC operating with pulsewidth modulation (PWM) This indicates that the application of conventional IGBT modules in high power MMCs is mainly constrained by the current switching capability and not by the power cycling lifetime.",
"author_names": [
"Gilbert Bergna",
"Salvatore D'Arco",
"Jon Are Suul",
"Magnar Hernes"
],
"corpus_id": 22488580,
"doc_id": "22488580",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Analysis of power cycling for semiconductor devices in modular multilevel converters",
"venue": "2016 IEEE 17th Workshop on Control and Modeling for Power Electronics (COMPEL)",
"year": 2016
},
{
"abstract": "In this article we investigate the different failure mechanisms in IGBT modules as a result of power cycling tests. The power cycling is carried out with different control strategies, such as constant current load, constant power and constant junction temperature. With the continuous monitoring of the tested device voltage, junction temperatures and periodic thermal transient tests, the crack of the wire bonds or even degradation of the die attach layer can be identified. A comparison between the effects of the studied control strategies on the lifetime of the tested device is also presented.",
"author_names": [
"Zoltan Sarkany",
"Andras Vass-Varnai",
"Sandor Laky",
"Marta Rencz"
],
"corpus_id": 34993671,
"doc_id": "34993671",
"n_citations": 11,
"n_key_citations": 1,
"score": 0,
"title": "Thermal transient analysis of semiconductor device degradation in power cycling reliability tests with variable control strategies",
"venue": "2014 Semiconductor Thermal Measurement and Management Symposium (SEMI THERM)",
"year": 2014
},
{
"abstract": "Power cycling in semiconductor modules contributes to repetitive thermal mechanical stresses, which in return accumulate as fatigue on the devices, and challenge the lifetime. Typically, lifetime models are expressed in number of cycles, within which the device can operate without failures under predefined conditions. In these lifetime models, thermal stresses (e.g. junction temperature variations) are commonly considered. However, the lifetime of power devices involves in cross disciplinary knowledge. As a result, the lifetime prediction is affected by the selected lifetime model. In this regard, this paper benchmarks the most commonly employed lifetime models of power semiconductor devices for offshore Modular Multilevel Converters (MMC) based wind farms. The benchmarking reveals that the lifetime model selection has a significant impact on the lifetime estimation. The use of analytical lifetime models should be justified in terms of applicability, limitations, and underlying statistical properties.",
"author_names": [
"Yi Zhang",
"Huai Wang",
"Zhongxu Wang",
"Yongheng Yang",
"Frede Blaabjerg"
],
"corpus_id": 2031269,
"doc_id": "2031269",
"n_citations": 32,
"n_key_citations": 1,
"score": 0,
"title": "Impact of lifetime model selections on the reliability prediction of IGBT modules in modular multilevel converters",
"venue": "2017 IEEE Energy Conversion Congress and Exposition (ECCE)",
"year": 2017
},
{
"abstract": "The power semiconductor switches are the most unreliable devices in the Photovoltaic (PV) energy conversion system. Thermal stress is the prime cause behind the power semiconductor switch failure mechanism, the selection of switching strategy and converter topology can have a notable effect on the converter reliability. This paper presents a lifetime comparison of Insulated Gate Bipolar Transistor (IGBT) modules in three classical multilevel inverter topologies on the basis of power cycling, thermal cycling, and lifetime performance. The electro thermal analysis has been implemented to identify the amplitude of the temperature swings and mean junction temperature. The Bayer lifetime model is used to evaluate the consumed lifetime of IGBT modules in the multilevel inverters based on the calculation method of numerical junction temperature. The accuracy in lifetime estimation has improved by considering the mission profile. The study shows that the IGBT modules in cascaded H bridge multilevel inverter have a higher lifetime when compared to the other two classical multilevel inverters",
"author_names": [
"Ranjith Kumar Gatla",
"Wei Chen",
"Guo-rong Zhu",
"Junqun Wang",
"Sainadh Singh Kshatri"
],
"corpus_id": 201066734,
"doc_id": "201066734",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "Lifetime comparison of IGBT modules in Grid connected Multilevel PV inverters Considering Mission Profile",
"venue": "2019 10th International Conference on Power Electronics and ECCE Asia (ICPE 2019 ECCE Asia)",
"year": 2019
},
{
"abstract": "Aluminium wires are widely used in power electronics modules to connect power semiconductor devices and other parts of the module electrically. Recently, other interconnect techniques have been proposed such as ribbon bond to improve the reliability, performance and reduce costs of power modules. The reliability of ribbon bond technique for an IGBT power module under power cycling is compared with that of conventional wire bond in this study using electro thermal nonlinear Finite Element Analysis. The results showed that a single ribbon of 2000mm x 200mm will replace three wire bonds of 400mm in diameter to achieve a similar module temperature distribution under same power load. Using the equivalent plastic strain increment per cycle, it is seen that the ribbon bond is more reliable than the wire bonds. The impact of neglecting joule heat in the wire/ribbon bonds during power cycling simulation has also been investigated.",
"author_names": [
"Kenneth Chimezie Nwanoro",
"Hua Lu",
"Chunyan Yin",
"Chris Bailey"
],
"corpus_id": 33485857,
"doc_id": "33485857",
"n_citations": 2,
"n_key_citations": 1,
"score": 0,
"title": "Computer simulation of the reliability of wire bonds and ribbon bonds in power electronics modules",
"venue": "2017 23rd International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)",
"year": 2017
}
] |
SHENG ZHANG gan | [
{
"abstract": "Gallium nitride (GaN) is a compound semiconductor that has tremendous potential to facilitate economic growth in a semiconductor industry that is silicon based and currently faced with diminishing returns of performance versus cost of investment. At a material level, its high electric field strength and electron mobility have already shown tremendous potential for high frequency communications and photonic applications. Advances in growth on commercially viable large area substrates are now at the point where power conversion applications of GaN are at the cusp of commercialisation. The future for building on the work described here in ways driven by specific challenges emerging from entirely new markets and applications is very exciting. This collection of GaN technology developments is therefore not itself a road map but a valuable collection of global state of the art GaN research that will inform the next phase of the technology as market driven requirements evolve. First generation production devices are igniting large new markets and applications that can only be achieved using the advantages of higher speed, low specific resistivity and low saturation switching transistors. Major investments are being made by industrial companies in a wide variety of markets exploring the use of the technology in new circuit topologies, packaging solutions and system architectures that are required to achieve and optimise the system advantages offered by GaN transistors. It is this momentum that will drive priorities for the next stages of device research gathered here.",
"author_names": [
"Hiroshi Amano",
"Y Baines",
"Matteo Borga",
"T Bouchet",
"Paul R Chalker",
"Matthew Charles",
"K J Chen",
"Nadim Chowdhury",
"Rongming Chu",
"Carlo De Santi",
"Maria Merlyne De Souza",
"Stefaan Decoutere",
"Lea Di Cioccio",
"Bernd Eckardt",
"Takashi Egawa",
"Patrick J Fay",
"Joseph J Freedsman",
"Louis Guido",
"Oliver Haberlen",
"Geoff Haynes",
"Thomas Heckel",
"Dilini Hemakumara",
"Peter A Houston",
"Jie Hu",
"Mengyuan Hua",
"Qingyun Huang",
"Alex Q Huang",
"Sheng Jiang",
"Hiroji Kawai",
"Daniel M Kinzer",
"Martin Kuball",
"Ashwani Kumar",
"Kean Boon Lee",
"Xu Li",
"Denis Marcon",
"Martin Marz",
"Robert McCarthy",
"Gaudenzio Meneghesso",
"Matteo Meneghini",
"Erwan Morvan",
"Akira Nakajima",
"E M Sankara Narayanan",
"Stephen Oliver",
"Tomas Palacios",
"Daniel Piedra",
"Marc Plissonnier",
"Rekha Reddy",
"Min-Chul Sun",
"Iain G Thayne",
"A Torres",
"Nicola Trivellin",
"Vineet Unni",
"Michael J Uren",
"Marleen Van Hove",
"David J Wallis",
"Jingshan Wang",
"Jinqiao Xie",
"Shuichi Yagi",
"Shu Yun Yang",
"C Youtsey",
"Ruiyang Yu",
"Enrico Zanoni",
"Stefan Zeltner",
"Yuhao Zhang"
],
"corpus_id": 4714529,
"doc_id": "4714529",
"n_citations": 426,
"n_key_citations": 4,
"score": 0,
"title": "The 2018 GaN power electronics roadmap",
"venue": "",
"year": 2018
},
{
"abstract": "Wide bandgap gallium nitride (GaN) based devices have attracted a lot of attention in optoelectronics, power electronics, and sensing applications. AlGaN/GaN based sensors, featuring high density and high mobility two dimensional electron gas (2DEG) have been demonstrated to be effective chemical sensors and biosensors in the liquid environment. One of the key factors limiting the wide adoption of the AlGaN/GaN liquid sensor is the package reliability issue. In this paper, the reliability of three types of sensor packaging materials (SiO2/Si3N4, PI, and SiO2/Si3N4/PI) on top of 5 mm metal are tested in Phosphate buffer saline (PBS) solution. By analyzing the I V characteristics, it is found that the leakage currents within different regimes follow distinct leakage models, whereby the key factors limiting the leakage current are identified. Moreover, the physical mechanisms of the package failure are illustrated. The failure of the SiO2/Si3N4 package is due to its porous structure such that ions in the solution can penetrate into the packaging material and reduce its resistivity. The failure of the PI package at a relatively low voltage <3 V) is mainly due to the poor adhesion of PI to the AlGaN surface such that the solution can reach the electrode by the \"lateral drilling\" effect. The SiO2/Si3N4/PI package achieves less than 10 mA leakage current at 5 V voltage stress because it combines the advantages of the SiO2/Si3N4 and the PI packages. The analysis in this work can provide guidelines for the design and failure mechanism analysis of packaging materials.",
"author_names": [
"Hanyuan Zhang",
"Shu Yang",
"Kuang Sheng"
],
"corpus_id": 216074035,
"doc_id": "216074035",
"n_citations": 3,
"n_key_citations": 0,
"score": 1,
"title": "The Leakage Mechanism of the Package of the AlGaN/GaN Liquid Sensor",
"venue": "Materials",
"year": 2020
},
{
"abstract": "Open gated AlGaN/GaN high electron mobility transistor (HEMT) based sensor can inherently deliver a high current sensitivity (SI) in response to the pH change. However, it remains a challenge to further improve the performance of the packaged AlGaN/GaN based sensor, due to a lack of investigation on the device design optimization. In this paper, the influence of the gate geometry on the device sensitivity is investigated through theoretical analysis and experiments. It has been found that the key factor limiting the current sensitivity is the series resistance (RS) of the packaged sensor. There are two cases: (1) when the aspect ratio of the gate structure (W/L) is small, the channel resistance dominates the total resistance and the current sensitivity increases with W/L; (2) when W/L is large, the RS dominates the total resistance, the sensitivity decreases with W/L. Therefore, there is an optimal W/L which can be approximately reached when W/L r2DEG/RS. Based on the guidelines, the current sensitivity of the AlGaN/GaN sensor with an optimized geometry in our experiment can reach 157 mA/pH, which is the highest value among the packaged AlGaN/GaN based pH sensors in literature, to our best knowledge. The comparison with the Si based ISFET and the impact of the gate membrane on the sensitivity of AlGaN/GaN based sensor have also been analyzed and discussed.",
"author_names": [
"Hanyuan Zhang",
"Jiawei Tu",
"Shu Yang",
"Kuang Sheng",
"Ping Wang"
],
"corpus_id": 199069857,
"doc_id": "199069857",
"n_citations": 11,
"n_key_citations": 1,
"score": 0,
"title": "Optimization of gate geometry towards high sensitivity AlGaN/GaN pH sensor.",
"venue": "Talanta",
"year": 2019
},
{
"abstract": "The InGaN/GaN multi quantum wells (MQWs) are prepared at the same condition by metal organic chemical vapor deposition (MOCVD) except the thickness of cap layers additionally grown on each InGaN well layer. The photoluminescence (PL) intensity of the thin cap layer sample is much stronger than that of thicker cap layer sample. Interestingly, the thick cap layer sample has two photoluminescence peaks under high excitation power, and the PL peak energy temperature curves show an anomalous transition from reversed V shaped to regular S shaped with increasing excitation power. Meanwhile, it exhibits a poorer thermal stability of thick cap layer sample under higher excitation power than that under lower excitation power. Such an untypical phenomenon is attributed to carrier redistribution between the two kinds of localized states which is induced by the inhomogeneous distribution of indium composition in thick cap layer sample. Furthermore, the luminescence of deep localized states has a better thermal stability, and the luminescence of shallow localized states has a poor thermal stability. In fact, such a severer inhomogeneous indium distribution may be caused by the degradation of subsequent epitaxial growth of InGaN/GaN MQWs region due to longer low temperature GaN cap layer growth time.",
"author_names": [
"Yao Xing",
"Degang Zhao",
"De-sheng Jiang",
"Zongshun Liu",
"Jian-jun Zhu",
"Ping Chen",
"Jing Yang",
"Feng Liang",
"Shuangtao Liu",
"Liqun Zhang"
],
"corpus_id": 78092734,
"doc_id": "78092734",
"n_citations": 6,
"n_key_citations": 0,
"score": 0,
"title": "Carrier Redistribution Between Two Kinds of Localized States in the InGaN/GaN Quantum Wells Studied by Photoluminescence",
"venue": "Nanoscale Research Letters",
"year": 2019
},
{
"abstract": "A high linearity and high gain AlGaN/GaN HEMTs with a 100 nm gate were demonstrated. The device employs transitional recessed gate (TRG) along the gate width for millimeter wave power application. The gradually changing gate recess depth was created using transitional dosed photoetching. Accurate etching ensured that the FET elements have a continued <inline formula> <tex math notation=\"LaTeX\"\\text{V}_{\\mathrm {ts} /tex math>/inline formula> offset in the local equivalent threshold voltage <inline formula> <tex math notation=\"LaTeX\"\\text{V}_{\\mathrm {th} /tex math>/inline formula> in different areas. The device exhibits a high <inline formula> <tex math notation=\"LaTeX\"\\text{I}_{\\mathrm {d,max} /tex math>/inline formula> of 1.12 A/mm and a high peak extrinsic <inline formula> <tex math notation=\"LaTeX\"\\text{g}_{\\mathrm {m} /tex math>/inline formula> of 374 mS/mm with an improved gate swing >2.6 V, much higher than that of Fin HEMT. Excellent RF performance was shown, including <inline formula> <tex math notation=\"LaTeX\"\\text{f}_{\\mathrm {T}\\text{f}_{\\mathrm {max} =61.8$ /tex math>/inline formula>/148.8 GHz, <inline formula> <tex math notation=\"LaTeX\"\\text{G}_{\\mathrm {as}\\text{G}_{\\mathrm {linear} {9.98} /tex math>/inline formula> 12dB at 30 GHz. To the best of our knowledge, this is the best associated gain and linearity performance reported to date for AlGaN/GaN HEMTs. This letter has great potential for high gain and linearity millimeter wave power applications, which are needed for future communication systems.",
"author_names": [
"Sheng Wu",
"Xiao-hua Ma",
"Ling Yang",
"Minhan Mi",
"Meng Zhang",
"Mei Wu",
"Yang Lu",
"Hengshuang Zhang",
"Chupeng Yi",
"Yue Hao"
],
"corpus_id": 169034154,
"doc_id": "169034154",
"n_citations": 6,
"n_key_citations": 0,
"score": 0,
"title": "A Millimeter Wave AlGaN/GaN HEMT Fabricated With Transitional Recessed Gate Technology for High Gain and High Linearity Applications",
"venue": "IEEE Electron Device Letters",
"year": 2019
},
{
"abstract": "This work evaluates the switching performance of 1.2 kV vertical GaN power FinFETs using the mixed mode device circuit TCAD simulation. The device simulation is calibrated with the I V and C V characteristics of experimental devices. A double pulse circuit is implemented in the mixed mode simulation and subsequently used to evaluate the device turn on/turn off times and switching losses under hard switching. To improve the switching performance of vertical power FinFETs, a novel inter fin design is proposed based on the split gate geometry. This structure removes the gate metal in the inter fin region and exposes the drift layer to the source metal. During the device turn (on)off transients, the drift layer underneath the inter fin gap region is (dis)charged by the drain to source current instead of gate current, leading to shorter switching times and lower switching losses. By utilizing this split gate structure, over 47% superior switching figure of merit (FOM) and over 30% lower switching losses have been demonstrated in 1.2 kV vertical GaN power FinFETs. The 1.2 kV, 80 mO split gate vertical GaN power FinFETs show over 30% superior switching FOM and over 50% smaller switching losses when compared to commercial 1.2 kV SiC MOSFETs under similar switching conditions. These results provide important guidelines for the design of vertical GaN power FinFETs and show their great potentials for high frequency medium voltage power applications.",
"author_names": [
"Hengyu Wang",
"Ming Xiao",
"Kuang Sheng",
"Tomas Palacios",
"Yuhao Zhang"
],
"corpus_id": 211227402,
"doc_id": "211227402",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Switching Performance Evaluation of 1200 V Vertical GaN Power FinFETs",
"venue": "2019 IEEE 7th Workshop on Wide Bandgap Power Devices and Applications (WiPDA)",
"year": 2019
},
{
"abstract": "Abstract Optical field leakage to the GaN substrate in GaN based green laser diodes (LDs) can reduce the peak optical gain and weaken the output performance of LDs. In this study, a graded indium composition n InxGa1 xN lower waveguide (LWG) structure is proposed which should be more feasible to grow with high material quality and at the same time can effectively reduce the optical field leakage in GaN based green LD, avoiding to use thick n type Al0.08Ga0.92N cladding layer or thick n InxGa1 xN LWG with high indium content. According to the optical and electrical characteristics of LDs calculated by LASTIP, it is found that the optical field has been concentrated around the active area and the optical field leakage has been eliminated effectively using graded indium composition LWG in green LDs, which results in an obvious improvement of optical and electrical performance.",
"author_names": [
"Feng Liang",
"Degang Zhao",
"De-sheng Jiang",
"Zongshun Liu",
"Jian-jun Zhu",
"Ping Chen",
"Jing Yang",
"Shuangtao Liu",
"Yao Xing",
"Liqun Zhang"
],
"corpus_id": 198462802,
"doc_id": "198462802",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Suppression of optical field leakage in GaN based green laser diode using graded indium n InxGa1 xN lower waveguide",
"venue": "Superlattices and Microstructures",
"year": 2019
},
{
"abstract": "Unpaired image to image translation problem aims to model the mapping from one domain to another with unpaired training data. Current works like the well acknowledged Cycle GAN provide a general solution for any two domains through modeling injective mappings with a symmetric structure. While in situations where two domains are asymmetric in complexity, i.e. the amount of information between two domains is different, these approaches pose problems of poor generation quality, mapping ambiguity, and model sensitivity. To address these issues, we propose Asymmetric GAN (AsymGAN) to adapt the asymmetric domains by introducing an auxiliary variable (aux) to learn the extra information for transferring from the information poor domain to the information rich domain, which improves the performance of state of the art approaches in the following ways. First, aux better balances the information between two domains which benefits the quality of generation. Second, the imbalance of information commonly leads to mapping ambiguity, where we are able to model one to many mappings by tuning aux, and furthermore, our aux is controllable. Third, the training of Cycle GAN can easily make the generator pair sensitive to small disturbances and variations while our model decouples the ill conditioned relevance of generators by injecting aux during training. We verify the effectiveness of our proposed method both qualitatively and quantitatively on asymmetric situation, label photo task, on Cityscapes and Helen datasets, and show many applications of asymmetric image translations. In conclusion, our AsymGAN provides a better solution for unpaired image to image translation in asymmetric domains.",
"author_names": [
"Yu Li",
"Sheng Tang",
"Rui Zhang",
"Yongdong Zhang",
"Jintao Li",
"Shuicheng Yan"
],
"corpus_id": 195261309,
"doc_id": "195261309",
"n_citations": 25,
"n_key_citations": 1,
"score": 0,
"title": "Asymmetric GAN for Unpaired Image to Image Translation",
"venue": "IEEE Transactions on Image Processing",
"year": 2019
},
{
"abstract": "In this paper, AlGaN/GaN Fin HEMTs with different fin configurations are theoretically and experimentally investigated. A simple physical based threshold voltage model for AlGaN/GaN Fin HEMTs is built for qualitative analysis. It is shown that the threshold voltage of AlGaN/GaN Fin HEMTs depends on the width and height of the fin structure. The peak value and linearity of transconductance and current gain cutoff frequency are improved by reducing the fin length. It is also found that the linearity of transconductance is sensitive to the fin height, which can be attributed to the capacitance control from sidewalls.",
"author_names": [
"Meng Zhang",
"Xiao-hua Ma",
"Ling Yang",
"Minhan Mi",
"Bin Hou",
"Yunlong He",
"Sheng Wu",
"Yang Lu",
"Heng-shuang Zhang",
"Qing Zhu",
"Jun Yin",
"Jiafeng Wu",
"Lin-An Yang",
"Yue Hao"
],
"corpus_id": 5011461,
"doc_id": "5011461",
"n_citations": 13,
"n_key_citations": 1,
"score": 0,
"title": "Influence of Fin Configuration on the Characteristics of AlGaN/GaN Fin HEMTs",
"venue": "IEEE Transactions on Electron Devices",
"year": 2018
},
{
"abstract": "Both yellow luminescence (YL) and blue luminescence (BL) bands of GaN films have been investigated for decades, but few works report the relationship between them. In this study, two sets of GaN samples grown via metalorganic chemical vapor deposition (MOCVD) were investigated. A close relationship was found between the YL and BL bands for unintentionally doped GaN and Si doped GaN samples, both of which were grown without intentional acceptor doping. It was found that the intensity ratio of blue luminescence to yellow luminescence (IBL/IYL) decreases sharply with the increase in carbon impurity concentration, even though both IBL and IYL increase obviously. It was also found that IBL/IYL decreases sharply with the increase in Si doping concentration. It is suggested that the C and Si impurities play important role in linkage and competition of the blue and yellow luminescence.",
"author_names": [
"Feng Liang",
"Degang Zhao",
"De-sheng Jiang",
"Zongshun Liu",
"Jianjun Zhu",
"Ping Chen",
"Jing Yang",
"Shuangtao Liu",
"Yao Xing",
"Liqun Zhang"
],
"corpus_id": 56488393,
"doc_id": "56488393",
"n_citations": 8,
"n_key_citations": 1,
"score": 0,
"title": "Role of Si and C Impurities in Yellow and Blue Luminescence of Unintentionally and Si Doped GaN",
"venue": "Nanomaterials",
"year": 2018
}
] |
muhammet emin yanik | [
{
"abstract": "Recent progress in complementary metal oxide semiconductor (CMOS) based frequency modulated continuous wave (FMCW) radars has made it possible to design low cost and low power millimeter wave (mmWave) sensors. As a result, there is a strong desire to exploit the progress in mmWave sensors in wide range of imaging applications including medical, automotive, and security. In this paper, we present a low cost high resolution mmWave imager prototype that combines commercially available 77 GHz system on chip FMCW radar sensors and synthetic aperture radar (SAR) signal processing techniques for concealed item detection. To create a synthetic aperture over a target scene, the imager is constructed with a two axis motorized rail system which can synthesize a large aperture in both horizontal and vertical directions. Our prototype system is described in detail along with signal processing techniques for two dimensional (2 D) image reconstruction. The imaging examples of concealed items in various scenarios confirm that our low cost prototype has a great potential for high resolution imaging tasks in security applications.",
"author_names": [
"Muhammet Emin Yanik",
"Murat Torlak"
],
"corpus_id": 155106118,
"doc_id": "155106118",
"n_citations": 11,
"n_key_citations": 1,
"score": 1,
"title": "Near Field 2 D SAR Imaging by Millimeter Wave Radar for Concealed Item Detection",
"venue": "2019 IEEE Radio and Wireless Symposium (RWS)",
"year": 2019
},
{
"abstract": "The primary challenge of a cost effective and low complexity near field millimeter wave (mmWave) imaging system is to achieve high resolution with a few antenna elements as possible. Multiple input multiple output (MIMO) radar using simultaneous operation of spatially diverse transmit and receive antennas is a good candidate to increase the number of available degrees of freedom. On the other hand, higher integration complexity of extremely dense transceiver electronics limits the use of MIMO only solutions within a relatively large imaging aperture. Hybrid concepts combining synthetic aperture radar (SAR) techniques and sparse MIMO arrays present a good compromise to achieve short data acquisition time and low complexity. However, compared with conventional monostatic sampling schemes, image reconstruction methods for MIMO SAR are more complicated. In this paper, we propose a high resolution mmWave imaging system combining 2 D MIMO arrays with SAR, along with a novel Fourier based image reconstruction algorithm using sparsely sampled aperture data. The proposed algorithm is verified by both simulation and processing real data collected with our mmWave imager prototype utilizing commercially available 77 GHz MIMO radar sensors. The experimental results confirm that our complete solution presents a strong potential in high resolution imaging with a significantly reduced number of antenna elements.",
"author_names": [
"Muhammet Emin Yanik",
"Murat Torlak"
],
"corpus_id": 85501355,
"doc_id": "85501355",
"n_citations": 25,
"n_key_citations": 3,
"score": 1,
"title": "Near Field MIMO SAR Millimeter Wave Imaging With Sparsely Sampled Aperture Data",
"venue": "IEEE Access",
"year": 2019
},
{
"abstract": "Objective: A significant proportion of nosocomial infections resulting in significant mortality and morbidity for hospitalized patients are due to the patients in intensive care units (ICU) For this reason, the identification and detection of antimicrobial resistance in the microorganisms that are isolated from ICU patients is of great importance for successful treatment. Therefore, in this study, it was aimed to evaluate Gram negative bacilli (GNB) isolated from patients in ICU of Erzurum Regional Training and Research Hospital, Turkey. Materials and Methods: A total of 327 GNB isolated from the clinical specimens of patients in ICU between January 2015 and January 2016 were evaluated. The conventional methods and the Kirby Bauer disc diffusion method (if necessary assisted with Vitek 2 automated system) were used for the identification and detection of antimicrobial susceptibility of isolated microorganisms. Antibiotic susceptibility tests were interpreted according to EUCAST criteria. Results: Of the 327 GNB, 218 were nonfermentative and 109 were Enterobacteriaceae spp. The most frequently isolated microorganisms were Acinetobacter baumannii and Klebsiella pneumoniae, respectively. The microorganisms were mostly isolated from respiratory tract samples and blood cultures. All of A. baumannii and Pseudomonas aeruginosa strains were *Hastane Infeksiyonlari Egitim Programi 2017'de (HIEP 2017) poster olarak sunulmustur. Poster No.002 (12 16 Nisan 2017, Ankara)",
"author_names": [
"Muhammet Emin Naldan",
"Mehmet Coskun",
"Onur Unal",
"Omer Karasahin",
"Mete Koray Vural"
],
"corpus_id": 79670652,
"doc_id": "79670652",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Evaluation of Gram Negative Bacilli Isolated from Patients in Intensive Care Units",
"venue": "",
"year": 2017
},
{
"abstract": "This paper presents the trade off between the array gain and the diversity loss in doubly correlated multiple input multiple output (MIMO) channels. In general, the array gain increases with increasing correlation at either side of the MIMO system. However, the bit error probability performance, i.e. the diversity gain, degrades with increasing correlation at either side of the MIMO system. However, the effects of correlation on the array and the diversity gains and the associated trade offs are not yet investigated in doubly correlated MIMO channels. The contribution of this paper is to determine the correlation regions in doubly correlated MIMO channels providing the optimum trade off between array and diversity gains.",
"author_names": [
"Seckin Anil Yildirim",
"Mehmet S;afak",
"Muhammet Emin Yanik"
],
"corpus_id": 13198781,
"doc_id": "13198781",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Diversity loss array gain tradeoff in doubly correlated MIMO beamforming systems",
"venue": "2010 IEEE 18th Signal Processing and Communications Applications Conference",
"year": 2010
},
{
"abstract": "Integration of multi chip cascaded multiple input multiple output (MIMO) millimeter wave (mmWave) sensors with synthetic aperture radar (SAR) imaging will enable cost effective and scalable solutions for a variety of applications including security, automotive, and surveillance. In this paper, the first three dimensional (3 D) holographic MIMO SAR imaging system using cascaded mmWave sensors is designed and implemented. The challenges imposed by the use of cascaded mmWave sensors in high resolution MIMO SAR imaging systems are discussed. Especially, important signal processing functions such as near field multistatic image reconstruction suitable for large MIMO apertures, multi channel array calibration, spatial sampling, and image resolution are presented in the context of 3 D MIMO SAR imaging. The prototyped 3 D MIMO SAR imaging system is described in detail, along with various real imaging results.",
"author_names": [
"Muhammet Emin Yanik",
"Dan Wang",
"Murat Torlak"
],
"corpus_id": 209772061,
"doc_id": "209772061",
"n_citations": 5,
"n_key_citations": 0,
"score": 1,
"title": "3 D MIMO SAR Imaging Using Multi Chip Cascaded Millimeter Wave Sensors",
"venue": "2019 IEEE Global Conference on Signal and Information Processing (GlobalSIP)",
"year": 2019
},
{
"abstract": "Sky tracking of permanent radio astronomical sky sources has been shown to be a promising alternative method to global positioning system (GPS) especially when GPS signals are either unavailable or may have been compromised. On the other hand, radio astronomical observations are increasingly corrupted by man made radio frequency interference (RFI) In this paper, radio astronomical geolocalization is investigated from the viewpoint of wideband measurements while combating RFI. The proposed geolocalization algorithm is designed as a joint iterative visibility phase reconstruction and localization algorithm based on unconstrained minimization. The effectiveness of the proposed algorithm is validated using simulated data. This approach can be extended to enable similar geolocating capability to ground based objects such as rovers, etc. on other celestial bodies in the solar system where there are no orbiting satellites like GPS.",
"author_names": [
"Muhammet Emin Yanik",
"Murat Torlak"
],
"corpus_id": 46962776,
"doc_id": "46962776",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Geolocalization via tracking of wideband radio astronomical sources in the presence of radio frequency interference",
"venue": "2018 IEEE/ION Position, Location and Navigation Symposium (PLANS)",
"year": 2018
},
{
"abstract": "Isletme varliklari icerisinde en yuksek paya sahip olan stoklarin Genel Kabul Gormus Muhasebe Ilkelerine, Muhasebenin Temel Kavramlarina, Uluslararasi ve Ulusal Muhasebe Standartlari ile vergi mevzuatina uygun olarak kayitlara alinip, alinmadiginin, degerleme olculerine uygun olarak degerlenerek finansal tablolarda durust bir bicimde raporlanip, raporlanmadiginin arastirilmasi stok hesaplarinin denetiminde temel amaci olusturmaktadir. Stoklarin dogru olarak raporlanabilmesi isletmede etkin bir belgeleme sisteminin ve ayrintili bir muhasebe kayit duzeninin kurulmasini gerektirmektedir. Bu da ancak isletmede uygun bir bicimde isletilen ic kontrol sisteminin varligina baglidir. Cunku isletmelerde etkin bir ic kontrol sisteminin varligi, guvenilir finansal raporlama yapilmasi, faaliyetlerin etkin ve verimli yurutulmesi, kanun ve duzenlemelere uygunluk anlamina gelmektedir. Bu nedenle stok hesaplarinda yer alan ve finansal tablolara yansitilan bilgilerle ilgili olarak isletme yonetiminin iddialarinin gercekten dogru olup, olmadiginin degisik denetim teknik ve yordamlari uygulanarak ortaya konulmasi ve stoklara iliskin tutarlarin finansal tablolarin durustlugunu gosterecek sekilde dogru bir bicimde raporlanarak bu tablolarda yer almasinin saglanmasi acisindan isletmede etkin bir ic kontrol sisteminin varligi ve ic denetim buyuk onem arz etmektedir.",
"author_names": [
"Yunus Ceran",
"Muhammet Bezirci"
],
"corpus_id": 178023683,
"doc_id": "178023683",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "STOK HESAPLARININ DENETIMINDE IC KONTROL SISTEMI VE IC DENETIMIN ONEMI",
"venue": "",
"year": 2011
},
{
"abstract": "",
"author_names": [
"Muhammet Emin Yanik"
],
"corpus_id": 125757419,
"doc_id": "125757419",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "RFI mitigation in low frequency all sky monitor (LOFASM) radio telescopes",
"venue": "",
"year": 2017
},
{
"abstract": "",
"author_names": [
"Muhammet Mo Yanik"
],
"corpus_id": 198835546,
"doc_id": "198835546",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Die Anerkennung des Islam als Religionsgemeinschaft in Deutschland: Die Frage der nicht staatlichen Korperschaft des offentlichen Rechts, der aktuelle Status und die moglichen Konsequenzen fur islamische Gemeinden bei einer Erteilung",
"venue": "",
"year": 2012
},
{
"abstract": "",
"author_names": [
"Muhammet Emin Yanik",
"Murat Torlak"
],
"corpus_id": 213557684,
"doc_id": "213557684",
"n_citations": 0,
"n_key_citations": 0,
"score": 1,
"title": "Simplified 2D mmWave Near Field Imaging",
"venue": "",
"year": 2019
}
] |
Semiconductor/boron nitride composites: Synthesis, properties, and photocatalysis applications | [
{
"abstract": "Abstract Semiconductor photocatalysis has been regarded as one of promising approach to solve the environmental pollution and energy crisis. Boron nitride (BN) as a new nanomaterial, has distinct structures and properties that can add attractive properties to photocatalysts. In the past few years, many encouraging achievements have been made in the research field of BN based semiconductor photocatalysts. Semiconductor/BN composites have attracted extensive attention due to its well photocatalytic activity. This work summarized recent progress on the synthesis of BN and semiconductor/BN composites. These semiconductor/BN composites have various applications in photocatalytic fields, such as pollutant degradation and photocatalytic hydrogen evolution. The role of BN in semiconductor/BN composites is discussed in depth. Coupling BN with semiconductors can improve the photocatalytic activity of semiconductors due to their surface charge transfer properties. The photocatalytic mechanisms and different types of photocatalysts are studied. Furthermore, perspectives on semiconductor/BN composites are discussed, including the challenges for large scale preparations and theoretical calculation of composites. It is expected that this review would be helpful for designing of highly efficient semiconductor/BN composites.",
"author_names": [
"Chengyun Zhou",
"Cui Lai",
"Chen Zhang",
"Guangming Zeng",
"Danlian Huang",
"Min Cheng",
"Liang Liang Hu",
"Weiping Xiong",
"Ming Chen",
"Jiajia Wang",
"Yang Yang",
"Longbo Jiang"
],
"corpus_id": 106071659,
"doc_id": "106071659",
"n_citations": 165,
"n_key_citations": 0,
"score": 1,
"title": "Semiconductor/boron nitride composites: Synthesis, properties, and photocatalysis applications",
"venue": "",
"year": 2018
},
{
"abstract": "Graphite carbon nitride (g C3N4) is well known as one of the most promising materials for photocatalytic activities, such as CO2 reduction and water splitting, and environmental remediation through the removal of organic pollutants. On the other hand, carbon nitride also pose outstanding properties and extensive application forecasts in the aspect of field emission properties. In this mini review, the novel structure, synthesis and preparation techniques of full bodied g C3N4 based composite and films were revealed. This mini review discussed contemporary advancement in the structure, synthesis, and diverse methods used for preparing g C3N4 nanostructured materials. The present study gives an account of full knowledge of the use of the exceptional structural and properties, and the preparation techniques of graphite carbon nitride (g C3N4) and its applications.",
"author_names": [
"Williams Kweku Darkwah",
"Yanhui Ao"
],
"corpus_id": 53961641,
"doc_id": "53961641",
"n_citations": 48,
"n_key_citations": 1,
"score": 0,
"title": "Mini Review on the Structure and Properties (Photocatalysis) and Preparation Techniques of Graphitic Carbon Nitride Nano Based Particle, and Its Applications",
"venue": "Nanoscale Research Letters",
"year": 2018
},
{
"abstract": "Foreword Preface COMBUSTION SYNTHESIS OF NITRIDES FOR DEVELOPMENT OF CERAMIC MATERIALS OF NEW GENERATION Introduction Peculiarities of Phase and Structure Formation of Metal and Nonmetal Nitrides in Combustion Mode Dependence of SHS Nitride Composition and Structure on Infiltration Combustion Mode SHS Equipment for Powder Synthesis Synthesis of SHS Ceramics Based on Silicon and Aluminum Nitrides and SiAlON Powders Direct Production of Materials and Items Based on Nitride Ceramics by SHS Gasostating Conclusion COMBUSTION SYNTHESIS OF BORON NITRIDE CERAMICS: FUNDAMENTALS AND APPLICATIONS Introduction Combustion in Boron Nitrogen System Mechanism of Structure Formation in CS Wave Combustion Synthesis of Nitride Based Ceramics Final Remarks COMBUSTION SYNTHESIS OF ALUMINUM NITRIDE (AIN) POWDERS WITH CONTROLLED GRAIN MORPHOLOGIES Introduction Combustion Synthesis of Quasi Aligned AlN Nanowhiskers Enhanced Thermal Conductivity of Polymer Composites Filled with 3D Brush Like AlN Nanowhiskers by Combustion Method Growth of Flower Like AlN by Combustion Synthesis Assisted with Mechanical Activation Combustion Synthesis of AlN Porous Shell Hollow Spheres Summary and Conclusions COMBUSTION SYNTHESIS AND SPARK PLASMA SINTERING OF ss SiAlON Introduction CS of High Purity ss SiAlON and Densification by SPS Physical Properties of CS SPSed ss SiAlON Corrosion Resistance Conclusions of This Chapter COMBUSTION SYNTHESIS OF AlN (Al3O3N) BN, ZrN, AND TiN IN AIR AND CERAMIC APPLICATION Thermochemical Features of Aluminum Particles Combustion (Theoretical Background) Chemical Features of Metals Combustion in Air (Experimental Background) Nitrides (Oxynitrides) Formation by Metal Powder Combustion in Air Applcation of the Synthesized Nitrides and Oxynitrides in Dense Ceramics COMBUSTION SYNTHESIS OF NITRIDES OF VANADIUM, NIOBIUM, AND TANTALUM Introduction Experimental Methods of Approach Results and Discussion Conclusions SYNTHESIS OF NITRIDES BY SHS OF FERROALLOYS IN NITROGEN Introduction Synthesis of Silicon Nitride by Combustion of Ferrosilicon in Nitrogen Synthesis of Vanadium Nitride by Combustion of Ferrovanadium in Nitrogen Synthesis of Niobium Nitride by Combustion of Ferrovniobium in Nitrogen Synthesis of Titanium Nitride by Combustion of Ferrovtitanium in Nitrogen Combustion of Ferrochromium in Nitrogen and Synthesis of Chromium Nitride Combustion of Ferroboron in Nitrogen and Synthesis of Boron Nitride Application Prospects of Products of Combustion of Ferroalloys in Nitrogen Conclusions HALIDES IN SHS AZIDE TECHNOLOGY OF NITRIDES OBTAINING Introduction The Use of Ammonia Halides The Use of Halides of Elements to be Nitrided The Use of Complexing Halides of Elements to be Nitrided and Alkaline Metals The Use of Complexing Halides of Ammonia and Elements to be Nitrided The Use of Halides for Obtaining Refractory Compositions Efficiency of Use of Halides in Azide SHS Systems Chemical Stages of Formation of Nitrides in a Mode SHS Az Property of SHS Az Powders Property of SHS Az Ceramics The Synthesis of Nanostructural SHS Az Powders Conclusion AlN CERAMICS FROM NANOSIZED PLASMA PROCESSED POWDER, ITS PROPERTIES AND APPLICATION Introduction: AlN Ceramics, its Characteristics and Application Production of AlN Ceramics from Nanosized Plasma Processed Powder Properties of AlN Ceramics from Nanosized Plasma Processed Powder Practical Application of Luminescence Properties of AlN Ceramics Conclusions AN OVERVIEW OF THE APPLICATION OF NITRIDES AND OXYNITRIDES IN PHOTOCATALYSIS AND ELECTROCATALYSIS Introduction Preparation Photocatalysis Electrocatalysis Conclusion CONCLUSION Index",
"author_names": [
"Alexander A Gromov",
"Liudmila N Chukhlomina"
],
"corpus_id": 99869937,
"doc_id": "99869937",
"n_citations": 16,
"n_key_citations": 1,
"score": 0,
"title": "Nitride Ceramics: Combustion Synthesis, Properties and Applications",
"venue": "",
"year": 2014
},
{
"abstract": "Abstract There has been increasing interest in the study of photocatalysis technology application in hydrogen production by splitting water because of environmental pollution and energy utilization. In this study, a high efficiency of the photocatalytic H2 production was achieved via graphene oxide (GO) and graphitic carbon nitride (g C3N4) composite photocatalysts (GO/g C3N4) The GO/g C3N4 photocatalysts possessed enhanced activities for hydrogen production than pure g C3N4 under visible light irradiation. The structural and optical properties of all the synthesized photocatalysts were successfully characterized by XRD, FTIR, XPS, UV vis spectra, TEM, SEM, N2 adsorption desorption and photoluminescence spectra techniques. Experimental results indicated that GO/g C3N4 photocatalysts can reach a high H2 production rate of 224.6 mmol/h (nearly 12 times of that obtained from pure g C3N4) at GO content of 0.5 wt and Pt 1 wt under visible light irradiation. The enhanced photocatalytic activity of GO/g C3N4 is ascribed to the ability of GO in accepting and transporting electrons from excited g C3N4, which promotes the charge separation. This work highlights that the affordable and abundant carbon material can be a good candidate for an electron attracting collector and transporter to efficiently lengthen the lifetime of the photogenerated charge carriers in the field of photocatalytic hydrogen production.",
"author_names": [
"Jiajia Li",
"Yuping Tang",
"Ruyi Jin",
"Qinghua Meng",
"Yanyan Chen",
"Xu Long",
"Liwen Wang",
"Hui Guo",
"Shuan Zhang"
],
"corpus_id": 202877514,
"doc_id": "202877514",
"n_citations": 15,
"n_key_citations": 0,
"score": 0,
"title": "Ultrasonic microwave assisted synthesis of GO/g C3N4 composites for efficient photocatalytic H2 evolution",
"venue": "Solid State Sciences",
"year": 2019
},
{
"abstract": "Abstract Carbon dots (CDs) an emerging fluorescent carbon nanomaterial, have attracted great attention in recent year due to their features such as unique optical property, good biocompatibility and low cost and easy synthesis. When CDs are integrated with porous materials, it not only compensates for the shortcomings of monocomponent CDs in applications, but also produces new functionalities through synergistic interactions to extend new applications. At present, CDs have been assembled with various porous materials such as zeolites, carbonaceous porous materials, porous graphitic carbon nitride (g C3N4) mesoporous SiO2, porous metallic compounds and metal organic frameworks (MOFs) which exhibit excellent performance and a wide range of applications. Therefore, recent research advances in CDs/porous materials composites should be presented to facilitate further development of the field. In this article, the preparation methods, porous structures, and properties of CDs/porous materials composites are classified and presented. Then, the applications of CDs/porous materials composites in optics, biomedicine, sensing, electrochemistry, and photocatalysis are also discussed. Finally, current challenges and future directions are briefly discussed to facilitate the next development of CDs/porous materials composites.",
"author_names": [
"Jiancang Chen",
"Guangchun Xiao",
"Gaigai Duan",
"Yongzhong Wu",
"Xiujian Zhao",
"Xiao Gong"
],
"corpus_id": 229478898,
"doc_id": "229478898",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Structural design of carbon dots/porous materials composites and their applications",
"venue": "",
"year": 2020
},
{
"abstract": "Graphitic carbon nitride (g C3N4) is a promising material for photocatalytic applications such as solar fuels production through CO2 reduction and water splitting, and environmental remediation through the degradation of organic pollutants. This promise reflects the advantageous photophysical properties of g C3N4 nanostructures, notably high surface area, quantum efficiency, interfacial charge separation and transport, and ease of modification through either composite formation or the incorporation of desirable surface functionalities. Here, we review recent progress in the synthesis and photocatalytic applications of diverse g C3N4 nanostructured materials, and highlight the physical basis underpinning their performance for each application. Potential new architectures, such as hierarchical or composite g C3N4 nanostructures, that may offer further performance enhancements in solar energy harvesting and conversion are also outlined.",
"author_names": [
"Santosh Kumar",
"Sekar Karthikeyan",
"Adam Fraser Lee"
],
"corpus_id": 55939020,
"doc_id": "55939020",
"n_citations": 109,
"n_key_citations": 0,
"score": 0,
"title": "g C3N4 Based Nanomaterials for Visible Light Driven Photocatalysis",
"venue": "",
"year": 2018
},
{
"abstract": "Progress in nanotechnology has led to the development of new classes of materials with unprecedented control of structure, composition, defects and resulting properties. Nanostructure ceramic materials have good chemical resistance, good mechanical resistance, corrosion resistance, electrical, optical and/or magnetic properties, good refractory properties, chemical inertness and hardness both at normal and high temperatures. The synthesis of nanostructured ceramic materials by the sol gel process plays a crucial role in the development of advanced materials with suitable properties for various applications. The synthesis process is based on the controlled hydrolysis and polycondensation of silica and alkoxides, which leads to the formation of nanoscale particles and their arrangement to a nanoporous network after gelation. Depending on ageing and drying conditions, either dense monolithic ceramic composites or nanoporous materials can be fabricated. These materials at nanoscale have attracted a lot of attention from researchers in various fields such as fuel cells, biomedical engineering, corrosion protective coatings, biotechnology, photocatalysis, genetics, etc. This chapter gives an insight into the fabrication of ceramic materials through the sol gel process and their possible applications in various fields. 1.1 General Introduction to Nanomaterials Nanomaterials are increasing an important product of nanotechnologies. Nanomaterials are usually considered to be materials in which the average particle size is smaller than 100 nm in at least one dimension. Within this size range E. Vunain S.B. Mishra A.K. Mishra B.B. Mamba Nanotechnology and Water Sustainability Research Unit, College of Science, Engineering and Technology, University of South Africa, Florida Campus, Johannesburg, South Africa e mail: [email protected] A.K. Mishra e mail: [email protected] (c) Springer International Publishing AG 2017 A.K. Mishra (ed. Sol gel Based Nanoceramic Materials: Preparation, Properties and Applications, DOI 10.1007/978 3 319 49512 5_1 1 (between 1 and 100 nm) the properties of the nanomaterials are quite different from the properties of the bulk materials. As a result, nanomaterials are developed to exhibit novel characteristics such as increased strength, chemical activity or conductivity compared to the same material at bulk scale. Generally, the physical, chemical, electrical and optical properties of nanomaterials are size and shape dependent and often exhibit differences from the bulk properties. This is attributed to the large number of surface or interface atoms shown by materials at this nanoscale range. Nanomaterials are coming into in use in energy and environmental applications, agriculture, electronics, healthcare, cosmetics and other areas [1 5] Structural materials are classified as ceramics, metals or polymers with each type of materials having its own advantages and limitations [6] Ceramic comes from the Greek word meaning \"pottery\" though pottery is just part of the ceramic world. The term \"ceramic\" covers inorganic non metallic materials that are formed by the action of heat to produced hard and strong mechanical properties [7] A ceramic is therefore an inorganic non metallic solid made up of either metal or non metal compounds that have been shaped and then hardened by heating to high temperatures. Ceramics are divided into two groups: traditional ceramics and advanced ceramics (engineering ceramics) However, nowadays advanced ceramics are further divided into three distinct categories: oxides ceramics (alumina, beryllium and zirconia) non oxides ceramics (borides, carbides, nitrides and silicides) and composites ceramics (particulate reinforced combinations of oxides and non oxides) [7] Metals are strong, cheap and tough, but they are heavy, chemically reactive and present limitations on maximum operating temperatures. Moreover, polymers are light and easily processable but can only be used at temperatures below 300 degC [6] Ceramics are brittle solids particularly suited for withstanding high temperatures. The different materials used in the fabrication of ceramics offer them a wide range of properties. Compared to metals and polymers, most ceramics possess useful features such as high temperature strength, chemical stability (the ability to withstand the damaging effects of oxygen, acids and chemicals due to their inertness) strength and brittleness, superior wear resistance and lower thermal and electrical conductivity (electrical insulators) The retention of these properties at elevated temperatures presents ceramic materials as a generic group to solving engineering application problems [8] Generally, these excellent characteristics features of ceramics make them more suitable for a wide range of applications. The field of ceramics stands as an interesting area of research more especially where nanoscience and nanotechnology have shown remarkable progress in the production of a variety of advanced materials with unique properties and performance. 1.1.",
"author_names": [
"Ajay Kumar Mishra"
],
"corpus_id": 138254972,
"doc_id": "138254972",
"n_citations": 11,
"n_key_citations": 0,
"score": 0,
"title": "Sol gel Based Nanoceramic Materials: Preparation, Properties and Applications",
"venue": "",
"year": 2017
},
{
"abstract": "Graphitic carbon nitride (g C3N4) is a promising material for photocatalytic applications such as solar fuels production through CO2 reduction and water splitting, and environmental remediation through the degradation of organic pollutants. This promise reflects the advantageous photophysical properties of g C3N4 nanostructures, notably high surface area, quantum efficiency, interfacial charge separation and transport, and ease of modification through either composite formation or the incorporation of desirable surface functionalities. Here, we review recent progress in the synthesis and photocatalytic applications of diverse g C3N4 nanostructured materials, and highlight the physical basis underpinning their performance for each application. Potential new architectures, such as hierarchical or composite g C3N4 nanostructures, that may offer further performance enhancements in solar energy harvesting and conversion are also outlined.",
"author_names": [
"Santosh Kumar",
"Sekar Karthikeyan",
"Adam Fraser Lee"
],
"corpus_id": 171089736,
"doc_id": "171089736",
"n_citations": 9,
"n_key_citations": 0,
"score": 0,
"title": "g C 3 N 4 Based Nanomaterials for Visible Light Driven Photocatalysis",
"venue": "",
"year": 2018
},
{
"abstract": "Heterogeneous photocatalysis plays a key role in the implementation of novel sustainable technologies, e.g. CO2 conversion into fuel, H2 production from water or organics degradation. The progress of photocatalysis relies on the development of tuneable photocatalysts and particularly the ability to build nanocomposites exhibiting synergistic properties with reduced electron hole recombination rates. We report for the first time the in situ synthesis of nanocomposites of carbon nitride nanosheets (CNNSs) and metal organic frameworks (MOFs) for application as photocatalysts. This approach leads to the 'nano scale mixing' of the components, thereby enabling a greater performance compared to other types of 2D materials/MOF composites typically obtained via physical mixing. The objective is to take advantage of the complementary features of the materials while forming a heterojunction. The structural, chemical, photophysical and electrochemical properties of the nanocomposites are characterized and compared to those of the parent materials and their physical mixture. The nanocomposites retain the high specific surface area and strong visible light absorbance of MIL 100(Fe) The intimate contact between the CNNSs and the MOF particles is found to promote the electron hole separation significantly due to the formation of a heterojunction. Hence, more efficient photocatalytic dye degradation is achieved over the composites than the physical mixture.",
"author_names": [
"Jindui Hong",
"Chunping Chen",
"Franky Esteban Bedoya",
"Geoff H Kelsall",
"Dermot O'Hare",
"Camille Petit"
],
"corpus_id": 100960722,
"doc_id": "100960722",
"n_citations": 80,
"n_key_citations": 1,
"score": 0,
"title": "Carbon nitride nanosheet/metal organic framework nanocomposites with synergistic photocatalytic activities",
"venue": "",
"year": 2016
},
{
"abstract": "BACKGROUND: Environmental pollution and energy crisis are nowadays considered among the most important problems facing humanity. Several strategies have been proposed to solve them, being photocatalysis a very promising one because of its ease of application and low cost. In the search for active photocatalysts, those based on graphite like carbon nitride (g C3N4) are becoming good alternatives for various reactions. In this work, the properties of g C3N4/MoS2/MnOOH composite material and its photocatalytic behavior for the production of hydrogen (H2) under UV radiation were investigated. RESULTS: The composite material was synthesized by applying a combination of thermal condensation and hydrothermal methods. According to the results of X ray diffraction (XRD) ultraviolet diffuse reflectance spectroscopy (UV DRS) scanning electron microscopy (SEM) X ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) good dispersion of the phases and the formation of a heterojunction were observed. The band gap value of the composite material, calculated by the Kubelka Munk equation using the values obtained from UV DRS analysis, was lower than those of the individual components, while it also had a much longer electron hole recombination time, according to photoluminescence analysis. As a consequence of a synergistic effect, the activity of the proposed composite photocatalyst was superior in the reaction of water splitting, with a kinetic constant of 466 mmol h 1 and a production rate of 1750 mmol H2gcat 1 h 1 (50 and 21% higher than those obtained with MoS2 and g C3N4, respectively) CONCLUSION: Because of its high activity and stability, g C3N4/MoS2/MnOOH composite photocatalyst is an excellent alternative for H2 production by the water splitting reaction. (c) 2019 Society of Chemical Industry",
"author_names": [
"K Jimenez-Rangel",
"Luis Lartundo-Rojas",
"Alejandra Garcia-Garcia",
"Sandra Cipagauta-Diaz",
"Angeles Mantilla",
"J Enrique Samaniego-Benitez"
],
"corpus_id": 182894821,
"doc_id": "182894821",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "Hydrothermal synthesis of a two dimensional g C 3 N 4 /MoS 2 /MnOOH composite material and its potential application as photocatalyst",
"venue": "Journal of Chemical Technology Biotechnology",
"year": 2019
}
] |
(AlxCr1 − x)2O3 | [
{
"abstract": "Detailed structural and optical properties of a (AlxCr1 x)2O3 (0 x 1) synthesized by the solid state reaction method have been investigated. Single phase a (AlxCr1 x)2O3 with space group R 3 c is obtained for the full composition range of 0 x 1. Variations in the lattice parameters a and c have been determined. Lattice parameter c follows Vegard's law, while the lattice parameter a shows a clear deviation with a bowing parameter of 0.035 A. This behavior of the lattice parameters of a (AlxCr1 x)2O3 with x is explained in detail by studying the local structure. Extended x ray absorption fine structure spectroscopy shows a reduction in the values of Cr O bond lengths with composition x. Optical absorption measurements of a (Al1 xCrx)2O3 for 0 x 1 show a large bandgap tunability of 1.9 eV (from 3.4 eV to 5.3 eV) The photoemission spectroscopy data and the analysis of partial density of states obtained from first principles electronic structure calculations suggest that the valence band maxima is mainly composed of Cr 3d levels, which hybridize with the O 2p levels. Increased contribution of O 2p partial density of states is observed with Al substitution, which is expected to enhance p type carrier conduction in the a (AlxCr1 x)2O3 system as compared to the parent a Cr2O3 system. Thus, the large bandgap, its tunability in the UV region, and the predicted enhancement of p type conductivity in the a (AlxCr1 x)2O3 system make it a potential candidate for application in UV based photo detectors and transparent electronics.",
"author_names": [
"Ravindra Jangir",
"Velaga Srihari",
"Ashok Bhakar",
"C Kamal",
"Pankaj R Sagdeo",
"Dharmendra Kumar",
"Shilpa Tripathi",
"S N Jha",
"Tapas Ganguli"
],
"corpus_id": 225149828,
"doc_id": "225149828",
"n_citations": 0,
"n_key_citations": 0,
"score": 1,
"title": "Structural and optical properties of transparent, tunable bandgap semiconductor: a (AlxCr1 x)2O3",
"venue": "",
"year": 2020
},
{
"abstract": "Density Functional Theory applying the generalised gradient approximation is used to study the phase stability of (AlxCr1 x)2O3 solid solutions in the context of physical vapour deposition (PVD) Our results show that the energy of formation for the hexagonal a phase is lower than for the metastable cubic g and B1 like phases independent of the Al content x. Even though this suggests higher stability of the a phase, its synthesis by physical vapour deposition is difficult for temperatures below 800 degC. Aluminium oxide and Al rich oxides typically exhibit a multi phased, cubic dominated structure. Using a model system of (Al0.69Cr0.31)2O3 which experimentally yields larger fractions of the desired hexagonal a phase, we show that point defects strongly influence the energetic relationships. Since defects and in particular point defects, are unavoidably present in PVD coatings, they are important factors and can strongly influence the stability regions. We explicitly show that defects with low formation ener.",
"author_names": [
"Christian Martin Koller",
"Nikola Koutna",
"Jurgen Ramm",
"Szilard Kolozsvari",
"Jorg Paulitsch",
"David Holec",
"Paul H Mayrhofer"
],
"corpus_id": 102083544,
"doc_id": "102083544",
"n_citations": 16,
"n_key_citations": 0,
"score": 0,
"title": "First principles studies on the impact of point defects on the phase stability of (AlxCr1 x)2O3 solid solutions",
"venue": "",
"year": 2016
},
{
"abstract": "We report on structural and optical properties for ternary a (AlxCr1 x)2O3 (0 x 1) solid solutions synthesized by using solid sate reaction method. Single R 3c phase was obtained for the Aluminum composition of 0 x 1. Due to difference in the ionic radia of Al3+ and Cr3+ in plane lattice parameter showed deviation from the vegard's law. Optical absorption spectra for the solid solutions showed a blue shift of 0.5 eV in the optical gap. It has also been observed that Cr 3d level shifted towards the O 2p level in the valance band which indicates the enhancement of hybridization in the d and p levels, which is related to the delocalization of hole states, responsible for p type conduction in wide band gap semiconductors. The results suggests that ternary a (AlxCr1 x)2O3 (0 x 1) can be useful in the field of UV transparent electronics and UV photodetectors.We report on structural and optical properties for ternary a (AlxCr1 x)2O3 (0 x 1) solid solutions synthesized by using solid sate reaction method. Single R 3c phase was obtained for the Aluminum composition of 0 x 1. Due to difference in the ionic radia of Al3+ and Cr3+ in plane lattice parameter showed deviation from the vegard's law. Optical absorption spectra for the solid solutions showed a blue shift of 0.5 eV in the optical gap. It has also been observed that Cr 3d level shifted towards the O 2p level in the valance band which indicates the enhancement of hybridization in the d and p levels, which is related to the delocalization of hole states, responsible for p type conduction in wide band gap semiconductors. The results suggests that ternary a (AlxCr1 x)2O3 (0 x 1) can be useful in the field of UV transparent electronics and UV photodetectors.",
"author_names": [
"Ravindra Jangir",
"Dharmendra Kumar",
"Velaga Srihari",
"Tapas Ganguli"
],
"corpus_id": 139283219,
"doc_id": "139283219",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Study on structural and optical properties of a (AlxCr1 x)2O3 (0 x 1) solid solutions",
"venue": "",
"year": 2018
},
{
"abstract": "Abstract The (AlxCr1 x)2O3/Co granular systems were synthesised by a convenient sol gel method combined with autocombustion. Well crystallised samples are obtained after being annealed at 1073 K for 1 h and all of them possess a porous structure. Exchange bias effect of all the samples is investigated at different temperatures. Exchange bias field and coercivity are affected noticeably by Al concentration and temperature. The different magnetic behaviour of the samples can be well explained in terms of the domain state model. Temperature dependence of magnetisation for sample x 0 is investigated and a large irreversibility is observed in the whole temperature range.",
"author_names": [
"S H Yang",
"Shu Jiang Liu",
"Y W Jiang",
"Sen Yang"
],
"corpus_id": 137615074,
"doc_id": "137615074",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Synthesis and exchange bias effect of (AlxCr1 x)2O3/Co granular systems",
"venue": "",
"year": 2012
},
{
"abstract": "Abstract (AlxCr1 x)2O3 coatings were synthesised by cathodic arc evaporation applying DC and pulsed substrate bias voltages to study the impact of different bias duty cycle settings on structure and morphology as well as mechanical and tribological properties. X ray diffraction revealed a corundum type (AlxCr1 x)2O3 phase structure for Al contents x 0.5 and the formation of an additional face centred cubic (Al Cr O) phase for x 0.5 for the pulsed bias situation, independently of the chosen duty cycle. In general, changes of the duty cycle in the manner of decreasing the electron current time duration along with an extension of the ion bombardment during growth lead to a reduction of the coatings' domain size, the formation of compressive residual stress as well as increasing coating hardness and Young's modulus. An amorphous like coating microstructure accompanied with diminished mechanical properties was observed when a DC substrate bias voltage was applied. The investigations illustrate the potential of tuning the properties of arc evaporated oxide coatings by adjusting the energetic particle bombardment during growth.",
"author_names": [
"Markus Pohler",
"Robert Franz",
"Jurgen Ramm",
"Peter Polcik",
"Christian Mitterer"
],
"corpus_id": 137707269,
"doc_id": "137707269",
"n_citations": 20,
"n_key_citations": 0,
"score": 0,
"title": "Influence of pulsed bias duty cycle variations on structural and mechanical properties of arc evaporated (Al,Cr)2O3 coatings",
"venue": "",
"year": 2015
},
{
"abstract": "Single layer and dual layer (AlxCr1 x)2O3 coatings were synthesised by cathodic arc evaporation with different Al contents to study their growth characteristics. It was demonstrated that variations in the Al content, the energy of incident particles and the coating thickness control the crystallinity and the coating texture. Analysis by X ray diffraction revealed a distinct (110) out of plane orientation after transition from a fine grained nucleation zone to a columnar growth mode. Furthermore, the impact of (AlxCr1 x)2O3 seed layers with x 0.25 and 0.5 on the growth of (AlxCr1 x)2O3 top layers with x 0.7 and 0.85 was evaluated in detail. According to X ray diffraction and transmission electron microscopy, the development of the corundum type crystal structure of the top layer was promoted by local epitaxy if the low Al containing seed layer exhibited a pronounced columnar structure. In this way, crystalline corundum type coatings with an Al content up to x 0.85 were obtained.",
"author_names": [
"Markus Pohler",
"Robert Franz",
"Jurgen Ramm",
"Peter Polcik",
"Christian Mitterer"
],
"corpus_id": 94302073,
"doc_id": "94302073",
"n_citations": 28,
"n_key_citations": 0,
"score": 1,
"title": "Seed layer stimulated growth of crystalline high Al containing (Al,Cr)2O3 coatings deposited by cathodic arc evaporation",
"venue": "",
"year": 2014
},
{
"abstract": "Abstract Fe Al Cr alloys have excellent oxidation resistance at high temperature. Many studies have been carried out on their oxidation resistance mechanism, mainly on the role of Al, but there is a lack of understanding of the role of Cr. According to existing research results, the structure of the metal/oxide interface of Fe Al Cr alloys has been investigated by the density functional theory. Due to the third component, which is chromium, Al2O3 films can be rapidly formed on the surface of Fe Al Cr alloys. Based on the density functional theory, an Fe(110)/Al2O3(0001) interface model was established. The Cr atoms in the alloy diffused at the Fe(110)/Al2O3(0001) interface and replaced the Al atoms in high temperature enviorment, resulting in the formation of a multilayer oxide (AlxCr1 x)2O3. In this paper, X ray diffraction (XRD) Field emission scanning electron microscopy (FESEM) Energy dispersive spectroscopy (EDS) and other experimental methods were employed to validate the multilayer oxide structure model. By calculating the interfacial bonding energy, it was concluded that the presence of Cr in Fe/Al2O3 increases the interfacial bonding energy, but with the diffusion of Cr from the alloy matrix to the oxides, the bonding energy gradually decreases.",
"author_names": [
"Jintao Wang",
"Shouping Liu",
"Xue Bai",
"Xiaohu Zhou",
"Xiao Han"
],
"corpus_id": 213050667,
"doc_id": "213050667",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Oxidation behavior of Fe Al Cr alloy at high temperature: Experiment and a first principle study",
"venue": "",
"year": 2020
},
{
"abstract": "Abstract The Al rich Al Cr O films were directly deposited on Si(100) substrate by reactive radio frequency magnetron sputtering (RFMS) using Al Cr alloy targets. The elemental composition and phase structure of the films deposited from alloy targets with different Cr content at low substrate temperature were analyzed by electron probe microanalysis (EPMA) grazing incident X ray diffraction (GIXRD) and transmission electron microscopy (TEM) The results show that the single corundum structured (Al0.7Cr0.3)2O3 solid solution films could be successfully synthesized by sputtering the Al70Cr30 target at low substrate temperature of 550 The phase structures of the films deposited from Al80Cr20 target exhibit a mixture of Al rich a (AlxCr1 x)2O3, Cr rich a (AlxCr1 x)2O3, g Al2O3 and amorphous phases when the substrate temperature was lower than 550 The formation of g phase could be suppressed at 600 while few amorphous alumina still remains in the film. In order to deposit single phase corundum type Al rich (AlxCr1 x)2O3 solid solution films at low temperature, the sufficient Cr content in the films is required.",
"author_names": [
"Y -T Cheng",
"Dongling Jiao",
"Z W Liu"
],
"corpus_id": 140038769,
"doc_id": "140038769",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "The influence of Cr content on the phase structure of the Al rich Al Cr O films deposited by magnetron sputtering at low temperature",
"venue": "Ceramics International",
"year": 2019
},
{
"abstract": "Abstract Various (AlxCr1 x)(O1 yNy) oxynitrides with different nitrogen non metal fractions y and two different multilayers thereof were developed by varying the synthetic air flow (without any other gas addition) during arc evaporation of powder metallurgically prepared Al0.70Cr0.30 cathodes. The (AlxCr1 x)(O1 yNy) oxynitride coatings crystallize with a single phase face centred cubic (fcc) (Al,Cr)N based structure for y 0.8, and with a phase composition of fcc (Al,Cr)2O3 like and corundum type a (Al,Cr)2O3 based structures for y The hardness of our as deposited (AlxCr1 x)(O1 yNy) oxynitrides, decreases from ~33 to 15 GPa with decreasing y from 0.8 to 0, while both multilayers demonstrate hardnesses of ~26 GPa. The onset temperature Tonset for thermally induced dissociation of Cr N bonds of our oxynitrides, to finally form Cr under N2 release, significantly increases from ~1000 to 1300 degC with decreasing N content y from 0.8 to 0.15. The multilayer with a smooth layer transition shows no mass loss up to the maximum temperature of 1500 degC, whereas that with a steep layer transition shows a mass loss due to N2 release with Tonset ~1250 degC. Dynamic oxidation treatments of our coatings in synthetic air up to 1500 degC indicate increased structural stability with decreasing nitrogen content y. Based on our results we can conclude, that by varying the synthetic air flow during arc evaporation of Al Cr cathodes (here, Al0.70Cr0.30) (AlxCr1 x)(O1 yNy) oxynitrides with y 0.8 can be prepared, having excellent mechanical properties and thermal stabilities.",
"author_names": [
"R Raab",
"Christian Martin Koller",
"Helmut Riedl",
"Szilard Kolozsvari",
"Jurgen Ramm",
"Paul H Mayrhofer"
],
"corpus_id": 150267872,
"doc_id": "150267872",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "The influence of synthetic air flow on the properties of arc evaporated Al Cr O N coatings",
"venue": "Thin Solid Films",
"year": 2019
},
{
"abstract": "Abstract The thermal stability of cathodic arc evaporated Al0.70Cr0.30 based AlxCr1 xN/(AlxCr1 x)2O3 multilayer coatings and their monolithic constituents was investigated by combining differential scanning calorimetry and thermal gravimetric analysis with X ray diffraction and transmission electron microscopy investigations. The formation of volatile Cr oxides within the monolithic (Al,Cr)2O3 coating is suggested by a depletion of Cr during annealing treatments beginning with ~1050 degC. The structural integrity of the AlxCr1 xN/(AlxCr1 x)2O3 multilayer coatings consisting of different interface architectures and number of layers increases with an increasing oxide nitride interface volume fraction up to ~1200 degC. The typically observed two step dissociation process of AlxCr1 xN (to form Cr2N and finally Cr under N2 release) is reduced to a delayed one step dissociation process. We could thus show, that combining AlxCr1 xN nitride coatings with (AlxCr1 x)2O3 is a promising approach in improving their thermal stability.",
"author_names": [
"R Raab",
"Christian Martin Koller",
"Szilard Kolozsvari",
"Jurgen Ramm",
"Paul H Mayrhofer"
],
"corpus_id": 140044356,
"doc_id": "140044356",
"n_citations": 6,
"n_key_citations": 0,
"score": 0,
"title": "Thermal stability of arc evaporated Al Cr O and Al Cr O/Al Cr N multilayer coatings",
"venue": "",
"year": 2018
}
] |
Optical emission from a charge-tunable quantum ring | [
{
"abstract": "Quantum dots or rings are artificial nanometre sized clusters that confine electrons in all three directions. They can be fabricated in a semiconductor system by embedding an island of low bandgap material in a sea of material with a higher bandgap. Quantum dots are often referred to as artificial atoms because, when filled sequentially with electrons, the charging energies are pronounced for particular electron numbers; this is analogous to Hund's rules in atomic physics. But semiconductors also have a valence band with strong optical transitions to the conduction band. These transitions are the basis for the application of quantum dots as laser emitters, storage devices and fluorescence markers. Here we report how the optical emission (photoluminescence) of a single quantum ring changes as electrons are added one by one. We find that the emission energy changes abruptly whenever an electron is added to the artificial atom, and that the sizes of the jumps reveal a shell structure.",
"author_names": [
"Richard John Warburton",
"C Schaflein",
"D Haft",
"F Bickel",
"Axel Lorke",
"Khaled Karrai",
"J M Garcia",
"Winston V Schoenfeld",
"P M Petroff"
],
"corpus_id": 4355292,
"doc_id": "4355292",
"n_citations": 693,
"n_key_citations": 10,
"score": 1,
"title": "Optical emission from a charge tunable quantum ring",
"venue": "Nature",
"year": 2000
},
{
"abstract": "Irradiating intercalated nanorings by optical vortices ignites a charge flow that emits coherent trains of high harmonic bursts with frequencies and time structures that are controllable by the topological charge of the driving vortex beam. Similar to synchrotron radiation, the polarization of emitted harmonics is also selectable by tuning to the appropriate emission angle with respect to the ring plane. The nonequilibrium orbital magnetic moment triggered in a ring tunnels quantum mechanically to smaller and larger rings leading respectively to high and low frequency harmonic generation. The frequencies of the emitted harmonics are tunable by simply changing the waist and/or the winding number of the optical vortex, without the need to increase the pulse intensity which can lead to material damage. These findings follow from full fledged quantum dynamic simulations for realistic material and laser parameters. The proposed setup is non destructive as only short vortex pulses of moderate intensities are needed, and it offers a versatile tool for nanoscale optical and spectroscopic applications such as local, single beam pump probe experiments.",
"author_names": [
"Jonas Watzel",
"Jamal Berakdar"
],
"corpus_id": 46827714,
"doc_id": "46827714",
"n_citations": 6,
"n_key_citations": 0,
"score": 0,
"title": "Tunable high harmonic pulses from nanorings swirled by optical vortices.",
"venue": "Optics express",
"year": 2017
},
{
"abstract": "The N 2 aryl 1,2,3 triazole derivatives (NATs) were developed as a new class of UV/blue light emitting fluorophores. Though both N 1 aryl 1,2,3 triazoles and N 2 aryl 1,2,3 triazoles gave strong photo absorption under excitation at 330 nm, only the N 2 analogous showed strong fluorescence emission in the UV/blue range with high efficiency in various solvents (quantum yield Ph around 0.3 0.5) Significant substituted group effects were observed, allowing tunable optical properties with emission (l(max) from 350 400 nm and Stokes shift from 38 93 nm. The computational studies along with X ray crystal structures indicated the significance of the effective conjugation between triazole ring and aryl groups on the N 2 position. The planar intramolecular charge transfer (PICT) mechanism was proposed, which was supported by solvent effect studies. Simple derivatizations gave NAT modified lysine and strong UV/blue emitting bis NAT (Ph=0.76, l(max)=390) which suggested the great potential of this new class of fluorophores in biological and material science research.",
"author_names": [
"Wuming Yan",
"Qiaoyi Wang",
"Quan Lin",
"Minyong Li",
"Jeffrey L Petersen",
"Xiaodong Shi"
],
"corpus_id": 37706529,
"doc_id": "37706529",
"n_citations": 61,
"n_key_citations": 2,
"score": 0,
"title": "N 2 aryl 1,2,3 triazoles: a novel class of UV/blue light emitting fluorophores with tunable optical properties.",
"venue": "Chemistry",
"year": 2011
},
{
"abstract": "Abstract We have succeeded in preparing excitons with a specific charge in single semiconductor quantum rings. Buried InAs quantum rings are loaded with electrons from a reservoir through a tunneling barrier and an additional electron hole pair is generated by optical excitation. Single rings are addressed with nano optical techniques. We observe abrupt shifts in the emission energy as electrons are added one by one. Furthermore, the experiments provide unique insights into the interaction of electrons in semiconductor nano islands with their environment.",
"author_names": [
"Richard John Warburton",
"C Schaflein",
"D Haft",
"F Bickel",
"Axel Lorke",
"Khaled Karrai",
"Jorge M Garcia",
"Winston V Schoenfeld",
"P M Petroff"
],
"corpus_id": 121767232,
"doc_id": "121767232",
"n_citations": 26,
"n_key_citations": 0,
"score": 0,
"title": "Optical emission from single, charge tunable quantum rings",
"venue": "",
"year": 2001
},
{
"abstract": "We have succeeded in preparing excitons with a speci c charge in single semiconductor quantum rings. Buried InAs quantum rings are loaded with electrons from a reservoir through a tunneling barrier and an additional electron hole pair is generated by optical excitation. Single rings are addressed with nano optical techniques. We observe abrupt shifts in the emission energy as electrons are added one by one. Furthermore, the experiments provide unique insights into the interaction of electrons in semiconductor nano islands with their environment. 2001 Elsevier Science B.V. All rights reserved.",
"author_names": [
"R J Warburtona",
"D Hafta",
"F Bickela",
"Andreas Lorkea",
"K Karraia",
"J M Garciab",
"W V Schoenfeldb",
"P M Petro"
],
"corpus_id": 55458960,
"doc_id": "55458960",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Optical emission from single charge tunable quantum rings",
"venue": "",
"year": 2000
},
{
"abstract": "We show that one dimensional (1d) GaN quantum wires (QWRs) exhibit intense and spectrally sharp emission lines. These QWRs are realized in an entirely self assembled growth process by molecular beam epitaxy (MBE) on the side facets of GaN/AlN nanowire (NW) heterostructures. Time integrated and time resolved photoluminescence (PL) data in combination with numerical calculations allow the identification and assignment of the manifold emission features to three different spatial recombination centers within the NWs. The recombination processes in the QWRs are driven by efficient charge carrier transfer effects between the different optically active regions, providing high intense QWR luminescence despite their small volume. This is deduced by a fast rise time of the QWR PL, which is similar to the fast decay time of adjacent carrier reservoirs. Such processes, feeding the ultra narrow QWRs with carriers from the relatively large NWs, can be the key feature towards the realization of future QWR based devices. While processing of single quantum structures with diameters in the nm range presents a serious obstacle with respect to their integration into electronic or photonic devices, the QWRs presented here can be analyzed and processed using existing techniques developed for single NWs.",
"author_names": [
"Jan Mussener",
"Ludwig A Th Greif",
"Stefan Kalinowski",
"Gordon Callsen",
"Pascal Hille",
"Jorg Schormann",
"M R Wagner",
"Andrei Schliwa",
"Sara Marti-Sanchez",
"Jordi Arbiol",
"Axel Hoffmann",
"Martin Eickhoff"
],
"corpus_id": 4242032,
"doc_id": "4242032",
"n_citations": 8,
"n_key_citations": 0,
"score": 0,
"title": "Optical emission of GaN/AlN quantum wires the role of charge transfer from a nanowire template.",
"venue": "Nanoscale",
"year": 2018
},
{
"abstract": "Abstract The capture cross section, intersubband optical cross section and non radiative emission rates related to localized hole states are obtained for p i n solar cells containing GaSb/GaAs quantum rings embedded within the i region of the device. The technique developed uses the intraband photoemission current to probe the charge state of the nanostructures during two color excitation. Analysis of the excitation power dependence revealed a non radiative hole capture lifetime of 12 ns under low excitation conditions, with high injection leading to the saturation of the hole occupancy within the quantum rings. The decay characteristics of the optical hole emission current has also been exploited to determine the spectral and temperature dependence of the radiative and non radiative hole escape mechanisms from the quantum rings.",
"author_names": [
"Magnus C Wagener",
"Denise Montesdeoca",
"Qi Lu",
"Andrew R J Marshall",
"Anthony Krier",
"Johannes Reinhardt Botha",
"Peter J Carrington"
],
"corpus_id": 106297329,
"doc_id": "106297329",
"n_citations": 7,
"n_key_citations": 1,
"score": 0,
"title": "Hole capture and emission dynamics of type II GaSb/GaAs quantum ring solar cells",
"venue": "",
"year": 2019
},
{
"abstract": "We demonstrate full charge control, narrow optical linewidths, and optical spin pumping on single self assembled InGaAs quantum dots embedded in a $162.5\\\\text{nm} thin diode structure. The quantum dots are just $88\\\\text{nm} from the top GaAs surface. We design and realize a p i n i n diode that allows single electron charging of the quantum dots at close to zero applied bias. In operation, the current flow through the device is extremely small resulting in low noise. In resonance fluorescence, we measure optical linewidths below $2\\\\mu\\text{eV} just a factor of two above the transform limit. Clear optical spin pumping is observed in a magnetic field of $0.5\\\\text{T} in the Faraday geometry. We present this design as ideal for securing the advantages of self assembled quantum dots highly coherent single photon generation, ultra fast optical spin manipulation in the thin diodes required in quantum nano photonics and nano phononics applications.",
"author_names": [
"Matthias C Lobl",
"Immo Sollner",
"Alisa Javadi",
"Tommaso Pregnolato",
"Rudiger Schott",
"Leonardo Midolo",
"A V Kuhlmann",
"Soren Stobbe",
"Andreas Dirk Wieck",
"Peter Lodahl",
"Arne Ludwig",
"Richard John Warburton"
],
"corpus_id": 32204194,
"doc_id": "32204194",
"n_citations": 19,
"n_key_citations": 1,
"score": 0,
"title": "Narrow optical linewidths and spin pumping on charge tunable close to surface self assembled quantum dots in an ultrathin diode",
"venue": "",
"year": 2017
},
{
"abstract": "Perovskite quantum emitters The development of many optical quantum technologies is dependent on the availability of solid state single quantum emitters with near perfect optical coherence. Light emitting defects in diamond and quantum dots grown by molecular beam epitaxy have demonstrated transform limited emission linewidths. However, they are limited in terms of production scalability and reproducibility between individual emitters. Utzat et al. now show that perovskite quantum dots can overcome these limitations and provide unprecedented versatility for the generation of indistinguishable single photons or entangled photon pairs for quantum information processing. Science, this issue p. 1068 Perovskite quantum dots could be used as scalable quantum emitters for quantum information processing. Chemically made colloidal semiconductor quantum dots have long been proposed as scalable and color tunable single emitters in quantum optics, but they have typically suffered from prohibitively incoherent emission. We now demonstrate that individual colloidal lead halide perovskite quantum dots (PQDs) display highly efficient single photon emission with optical coherence times as long as 80 picoseconds, an appreciable fraction of their 210 picosecond radiative lifetimes. These measurements suggest that PQDs should be explored as building blocks in sources of indistinguishable single photons and entangled photon pairs. Our results present a starting point for the rational design of lead halide perovskite based quantum emitters that have fast emission, wide spectral tunability, and scalable production and that benefit from the hybrid integration with nanophotonic components that has been demonstrated for colloidal materials.",
"author_names": [
"Hendrik Utzat",
"Weiwei Sun",
"Alexander E K Kaplan",
"Franziska Krieg",
"Matthias Ginterseder",
"Boris Spokoyny",
"Nathan D Klein",
"Katherine E Shulenberger",
"Collin F Perkinson",
"Maksym V Kovalenko",
"Moungi G Bawendi"
],
"corpus_id": 72336088,
"doc_id": "72336088",
"n_citations": 148,
"n_key_citations": 0,
"score": 0,
"title": "Coherent single photon emission from colloidal lead halide perovskite quantum dots",
"venue": "Science",
"year": 2019
},
{
"abstract": "We report on the optical properties of single InAs/GaAs quantum dots emitting near the telecommunication O band, probed via Coulomb blockade and nonresonant photoluminescence spectroscopy, in the presence of external electric and magnetic fields. We extract the physical properties of the electron and hole wave functions, including the confinement energies, interaction energies, wave function lengths, and g factors. For excitons, we measure the permanent dipole moment, polarizability, diamagnetic coefficient, and Zeeman splitting. The carriers are determined to be in the strong confinement regime. Large range electric field tunability, up to 7 meV, is demonstrated for excitons. We observe a large reduction, up to one order of magnitude, in the diamagnetic coefficient when rotating the magnetic field from Faraday to Voigt geometry due to the unique dot morphology. The complete spectroscopic characterization of the fundamental properties of long wavelength dot in a well structures provides insight for the applicability of quantum technologies based on quantum dots emitting at telecom wavelengths.",
"author_names": [
"Luca Sapienza",
"Rima Al-Khuzheyri",
"Adetunmise C Dada",
"Andrew Griffiths",
"Edmund Clarke",
"Brian D Gerardot"
],
"corpus_id": 8554196,
"doc_id": "8554196",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "Magneto optical spectroscopy of single charge tunable InAs/GaAs quantum dots emitting at telecom wavelengths",
"venue": "",
"year": 2016
}
] |
gate dielectric high-k | [
{
"abstract": "A newly synthesized high k polymeric insulator for use as gate dielectric layer for organic field effect transistors (OFETs) obtained by grafting poly(methyl methacrylate) (PMMA) in poly(vinylidene fluoride trifluoroethylene) (P(VDF TrFE) via atom transfer radical polymerization transfer is reported. This material design concept intents to tune the electrical properties of the gate insulating layer (capacitance, leakage current, breakdown voltage, and operational stability) of the high k fluorinated polymer dielectric without a large increase in operating voltage by incorporating an amorphous PMMA as an insulator. By controlling the grafted PMMA percentage, an optimized P(VDF TrFE) g PMMA with 7 mol% grafted PMMA showing reasonably high capacitance (23 30 nF cm 2) with low voltage operation and negligible current hysteresis is achieved. High performance low voltage operated top gate/bottom contact OFETs with widely used high mobility polymer semiconductors, poly[[2,5 bis(2 octyldodecyl) 2,3,5,6 tetrahydro 3,6 dioxopyrrolo [3,4 c]pyrrole 1,4 diyl] alt [2,2' (2,5 thiophene)bis thieno(3,2 b)thiophene] 5,5' diyl] (DPPT TT) and poly([N,N' bis(2 octyldodecyl) naphthalene 1,4,5,8 bis(dicarboximide) 2,6 diyl] alt 5,5' (2,2' bithiophene) are demonstrated here. DPPT TT OFETs with P(VDF TrFE) g PMMA gate dielectrics exhibit a reasonably high field effect mobility of over 1 cm2 V 1 s 1 with excellent operational stability.",
"author_names": [
"Eul-Yong Shin",
"Hye Jin Cho",
"Sungwook Jung",
"Changduk Yang",
"Yong-Young Noh"
],
"corpus_id": 103442216,
"doc_id": "103442216",
"n_citations": 37,
"n_key_citations": 0,
"score": 1,
"title": "A High k Fluorinated P(VDF TrFE) g PMMA Gate Dielectric for High Performance Flexible Field Effect Transistors",
"venue": "",
"year": 2018
},
{
"abstract": "In this work, low temperature fabrication of a sputtered high k HfO2 gate dielectric for flexible a IGZO thin film transistors (TFTs) on polyimide substrates was investigated. The effects of Ar pressure during the sputtering process and then especially the post annealing treatments at low temperature =200 degC) for HfO2 on reducing the density of defects in the bulk and on the surface were systematically studied. X ray reflectivity, UV vis and X ray photoelectron spectroscopy, and micro wave photoconductivity decay measurements were carried out and indicated that the high quality of optimized HfO2 film and its high dielectric properties contributed to the low concentration of structural defects and shallow localized defects such as oxygen vacancies. As a result, the well structured HfO2 gate dielectric exhibited a high density of 9.7 g/cm3, a high dielectric constant of 28.5, a wide optical bandgap of 4.75 eV, and relatively low leakage current. The corresponding flexible a IGZO TFT on polyimide exhibited an optimal device performance with a saturation mobility of 10.3 cm2 V 1 s 1, an Ion/Ioff ratio of 4.3 x 107, a SS value of 0.28 V dec 1, and a threshold voltage (Vth) of 1.1 V, as well as favorable stability under NBS/PBS gate bias and bending stress.",
"author_names": [
"Rihui Yao",
"Zheng Zeke",
"Mei Xiong",
"Zhang Xiaochen",
"Liu Xiaoqing",
"Honglong Ning",
"Zhiqiang Fang",
"Weiguang Xie",
"Xubing Lu",
"Junbiao Peng"
],
"corpus_id": 126252046,
"doc_id": "126252046",
"n_citations": 46,
"n_key_citations": 0,
"score": 0,
"title": "Low temperature fabrication of sputtered high k HfO2 gate dielectric for flexible a IGZO thin film transistors",
"venue": "",
"year": 2018
},
{
"abstract": "Enhancement mode GaN MOS HEMTs with a uniform threshold voltage <inline formula> <tex math notation=\"LaTeX\"{V}_{\\text {th}\\sim \\text {2.2 \\pm \\text {0.25} /tex math>/inline formula> V at <inline formula> <tex math notation=\"LaTeX\"{I}_{D} \\text {1}\\mu \\text{A} /tex math>/inline formula>/mm) have been achieved by a recess free barrier engineering technique in conjunction with a high <inline formula> <tex math notation=\"LaTeX\"{k} /tex math>/inline formula> gate dielectric. The design includes an ultrathin ~6 nm) Al<sub>0.2</sub>Ga<sub>0.8</sub>N barrier preserving the two dimensional electron gas (2DEG) mobility underneath the gate and a selective area barrier regrowth to restore the 2DEG at the access regions. A high <inline formula> <tex math notation=\"LaTeX\"{k} /tex math>/inline formula> ZrO<sub>2</sub> gate dielectric was employed to enhance the gate control over the channel. The common issue of recess induced damage was mitigated. The high quality gate stack results not only in a highly uniform and large <inline formula> <tex math notation=\"LaTeX\"{V}_{\\text {th} /tex math>/inline formula> but also small hysteresis, minimal gate lag, low on resistance, and high output current in the E MOS HEMTs.",
"author_names": [
"Huaxing Jiang",
"Chak Wah Tang",
"Kei May Lau"
],
"corpus_id": 3687166,
"doc_id": "3687166",
"n_citations": 27,
"n_key_citations": 1,
"score": 0,
"title": "Enhancement Mode GaN MOS HEMTs With Recess Free Barrier Engineering and High {k} ZrO2 Gate Dielectric",
"venue": "IEEE Electron Device Letters",
"year": 2018
},
{
"abstract": "Abstract This paper investigates the performance of 6 T SRAM cell using high K gate dielectric based junctionless silicon nanotube FET (JLSiNTFET) It is observed that the use of high K gate dielectric enhances the delay performance of the JLSiNTFET based 6 T SRAM cell. Read access time (RAT) and write access time (WAT) improves by ~18% and ~20% when TiO 2 is used as gate dielectric instead of SiO 2 The hold, read, and write SNMs (static noise margin) of the 6 T SRAM cell also improves marginally by the use of high K gate dielectric. Furthermore, it is also observed that the improvement in hold SNM (HSNM) read SNM (RSNM) and write SNM (WSNM) can be boosted by using higher interfacial layer thickness (T I However, the improvement in read access times (RAT) write access time (WAT) degrades at higher T I Thus, high K gate dielectrics with high interfacial layer thickness are more suitable for JLSiNT FET based 6 T SRAM cell.",
"author_names": [
"Shubham Tayal",
"Ashutosh Nandi"
],
"corpus_id": 125496380,
"doc_id": "125496380",
"n_citations": 16,
"n_key_citations": 0,
"score": 0,
"title": "Study of 6T SRAM cell using High K gate dielectric based junctionless silicon nanotube FET",
"venue": "",
"year": 2017
},
{
"abstract": "MoS2 and other atomic level thick layered materials have been shown to have a high potential for outperforming Si transistors at the scaling limit. In this work, we demonstrate a MoS2 transistor with a low voltage and high ON/OFF ratio. A record small equivalent oxide thickness of ~1.1 nm has been obtained by using ultra high k gate dielectric Pb(Zr0.52Ti0.48)O3. The low threshold voltage <0.5 V) is comparable to that of the liquid/gel gated MoS2 transistor. The small sub threshold swing of 85.9 mV dec( 1) the high ON/OFF ratio of ~10(8) and the negligible hysteresis ensure a high performance of the MoS2 transistor operating at 1 V. The extracted field effect mobility of 1 10 cm(2) V( 1) s( 1) suggests a high crystalline quality of the CVD grown MoS2 flakes. The combination of the two dimensional layered semiconductor and the ultra high k dielectric may enable the development of low power electronic applications.",
"author_names": [
"Changjian Zhou",
"Xinsheng Wang",
"Salahuddin Raju",
"Ziyuan Lin",
"D Villaroman",
"Baoling Huang",
"Helen L W Chan",
"Mansun Chan",
"Yang Chai"
],
"corpus_id": 19618187,
"doc_id": "19618187",
"n_citations": 92,
"n_key_citations": 1,
"score": 0,
"title": "Low voltage and high ON/OFF ratio field effect transistors based on CVD MoS2 and ultra high k gate dielectric PZT.",
"venue": "Nanoscale",
"year": 2015
},
{
"abstract": "Black phosphorus (BP) is the most stable allotrope of phosphorus which exhibits strong in plane anisotropic charge transport. Discovering its interface properties between BP and high k gate dielectric is fundamentally important for enhancing the carrier mobility and electrostatics control. Here, we investigate the impact of interface engineering on the transport properties of BP transistors with an ultra thin hafnium dioxide (HfO2) gate dielectric of ~3.4 nm. A high hole mobility of ~536 cm2V 1s 1 coupled with a near ideal subthreshold swing (SS) of ~66 mV/dec were simultaneously achieved at room temperature by improving the BP/HfO2 interface quality through thermal treatment. This is attributed to the passivation of phosphorus dangling bonds by hafnium (Hf) adatoms which produces a more chemically stable interface, as evidenced by the significant reduction in interface states density. Additionally, we found that an excessively high thermal treatment temperature (beyond 200 degC) could detrimentally modify the BP crystal structure, which results in channel resistance and mobility degradation due to charge impurities scattering and lattice displacement. This study contributes to an insight for the development of high performance BP based transistors through interface engineering.",
"author_names": [
"Zhi Peng Ling",
"Juntao Zhu",
"Xinke Liu",
"Kah-Wee Ang"
],
"corpus_id": 15520448,
"doc_id": "15520448",
"n_citations": 28,
"n_key_citations": 0,
"score": 0,
"title": "Interface Engineering for the Enhancement of Carrier Transport in Black Phosphorus Transistor with Ultra Thin High k Gate Dielectric",
"venue": "Scientific reports",
"year": 2016
},
{
"abstract": "The microstructure, optical and electrical properties of HfTiO high k gate dielectric thin films deposited on Si substrate and quartz substrate by RF magnetron sputtering have been investigated. Based on analysis from x ray diffraction (XRD) measurements, it has been found that the as deposited HfTiO films remain amorphous regardless of the working gas pressure. Meanwhile, combined with characterization of ultraviolet visible spectroscopy (UV vis) and spectroscopy ellipsometry (SE) the deposition rate, band gap and optical properties of sputtered HfTiO gate dielectrics were determined. Besides, by means of the characteristic curves of high frequency capacitance voltage (C V) and leakage current density voltage (J V) the electrical parameters, such as permittivity, total positive charge density, border trap charge density, and leakage current density, have been obtained. The leakage current mechanisms are also discussed. The energy band gap of 3.70 eV, leakage current density of 1.39x10 5 A/cm2 at bias voltage of 2 V, and total positive charge density and border trap charge density of 9.16x1011 cm 2 and 1.3x1011 cm 2, respectively render HfTiO thin films deposited at 0.6 Pa, potential high k gate dielectrics in future CMOS devices.",
"author_names": [
"S S Jiang",
"Gang He",
"J S Gao",
"D Q Xiao",
"P Jin",
"Weijie Li",
"Jianguo Lv",
"Meng Liu",
"Yanmei Liu",
"Zhaoqi Sun"
],
"corpus_id": 137754927,
"doc_id": "137754927",
"n_citations": 14,
"n_key_citations": 0,
"score": 0,
"title": "Microstructure, optical and electrical properties of sputtered HfTiO high k gate dielectric thin films",
"venue": "",
"year": 2016
},
{
"abstract": "Abstract Flexible OFET memory devices of semiconducting poly(9,9 dioctylfluorene alt bithiophene) (F8T2) on PEN substrates were fabricated and characterized using a high k poly(vinylidene fluoride co trifluoroethylene) (P(VDF TrFE) gate dielectric combined with donor acceptor polyimide electrets of (poly[2,5 bis(4 aminophenylenesulfanyl)selenophene hexafluoroisopropylidene diphthalimide] (APSP 6FDA) or poly[2,5 bis(4 aminophenylenesulfanyl)thiophene hexafluoroisopropylidenediphthalimide] (APST 6FDA) All the polymer thin films, including gate dielectric, charge storage, and semiconducting layer, possessed a smooth surface to form good contact adhesion between each layer, as confirmed by atomic force microscopy. The flexible OFET device could be operated using low gate voltage 3 The data storage characteristic was mainly attributed to the charge trapping in polyimide layer under a positive or negative gate bias. The studied flexible memories, moreover, exhibited stable electrical parameters, such as charge carrier mobility, threshold voltage change, and memory window, under a bending radius of 10 mm with 1000 repeating cycles, resulting in reproducible and reliable device characteristics. The experimental results indicated that a low voltage operated non volatile flexible OFET memory device could be simply integrated using all polymer components, including gate dielectric, charge storage electret, and semiconductor.",
"author_names": [
"Mao-Shen Lu",
"Hung-Chin Wu",
"Yu-Wei Lin",
"Mitsuru Ueda",
"Wen-Chang Chen"
],
"corpus_id": 101451814,
"doc_id": "101451814",
"n_citations": 15,
"n_key_citations": 0,
"score": 0,
"title": "Low voltage operation of non volatile flexible OFET memory devices using high k P(VDF TrFE) gate dielectric and polyimide charge storage layer",
"venue": "",
"year": 2016
},
{
"abstract": "Now a days, high k dielectrics have been investigated as an alternative to Silicon dioxide (SiO\"2) based gate dielectric for nanoscale semiconductor devices. This paper is an attempt to characterize the analog and RF performance of the high k metal gate (HKMG) double gate (DG) metal oxide semiconductor field effect transistor (MOSFET) in nanoscale through 2 D device simulation. The results demonstrates the impact of high k oxide layer as single and gate stack (GS) The key idea behind this investigation is to provide a physical explanation for the improved analog and RF performance exhibited by the device. The major figures of merit (FOMs) studied in this paper are transconductance (g\"m) output conductance (g\"d) transconductance generation factor (g\"m/I\"D) early voltage (V\"E\"A) intrinsic gain (A\"V) cut off frequency (f\"T) transconductance frequency product (TFP) gain frequency product (GFP) and gain transconductance frequency product (GTFP) The effects of downscaling of channel length (L) on analog performance of the proposed devices have also been presented. It has been observed that the performance enhancement of GS configurations (k=7.5 i.e device D5 in the study) is encouraging as far as the nanoscale DG MOSFET is concerned. Also it significantly reduces the short channel effects (SCEs) Parameters like DC gain of (91.257dB, 43.436dB) nearly ideal values (39.765V^ ^1, 39.589V^ ^1) of TGF, an early voltage of (2.73V, 16.897V) cutoff frequency (294GHz, 515.5GHz) and GTFP of (5.14x10^5GHz/V, 1.72x10^5GHz/V) for two different values of V\"D\"S=0.1V and 0.5V respectively are found to be close to ideal values. Analysis shows an opportunity for realizing high performance analog and RF circuits with the device proposed in this paper i.e. device D5.",
"author_names": [
"Kumar Prasannajit Pradhan",
"Sushanta Kumar Mohapatra",
"Prasanna Kumar Sahu",
"D K Behera"
],
"corpus_id": 42140211,
"doc_id": "42140211",
"n_citations": 105,
"n_key_citations": 3,
"score": 1,
"title": "Impact of high k gate dielectric on analog and RF performance of nanoscale DG MOSFET",
"venue": "Microelectron. J.",
"year": 2014
},
{
"abstract": "Solution processed low voltage organic thin film transistors (OTFTs) were fabricated using the high mobility donor acceptor copolymer semiconductor indacenodithiophene co benzothiadiazole (IDTBT) and large permittivity (high k) relaxor ferroelectric polymer poly (vinylidene fluoride trifluoroethylene chlorofloroethylene) It is shown that, with the face on molecule packing in as deposited IDTBT films, the close interfacing between the backbone and the dielectric layer causes significant mobility degradation of the fabricated OTFTs due to dipole effects. By inserting a thin, low polar dielectric layer between the high k one and the channel, the dipole field can be effectively screened and the devices present a high mobility similar to that of previously reported high voltage IDTBT OTFTs. With the bilayer gate dielectric and the IDTBT semiconductor, low voltage OTFTs are achieved with the average mobility of 1.4 cm2/V* s and ON/OFF current ratio larger than 106, which is among the best reported performance so far for solution processed low voltage OTFTs.",
"author_names": [
"Wei Tang",
"Jinhua Li",
"Jiaqing Zhao",
"Weimin Zhang",
"Feng Yan",
"Xiaojun Guo"
],
"corpus_id": 8953103,
"doc_id": "8953103",
"n_citations": 45,
"n_key_citations": 0,
"score": 0,
"title": "High Performance Solution Processed Low Voltage Polymer Thin Film Transistors With Low $k$ /High $k$ Bilayer Gate Dielectric",
"venue": "IEEE Electron Device Letters",
"year": 2015
}
] |
-Al2O3 layer amorphous-phase structure | [
{
"abstract": "Metal insulator semiconductor (MIS) structures were fabricated on n type variband HgCdTe with Al2O3 deposited by plasma enhanced ALD. Early stages of the deposition process performed at 120 degC were studied by means of XPS for the first time. Partial decomposition and conversion of HgCdTe native oxide presented on the surface were observed as well as mercury atoms out diffusion from the near surface region. The width of alumina band gap and the offsets of Al2O3/HgCdTe bands were determined. Capacitance voltage characteristics reveal a negative fixed charge with the density of ~1 x 1012 cm 2 and wide hysteresis depending on the voltage sweep range. An additional intermediate layer lowering an apparent permittivity value of the MIS insulator layer is found. By varying the thickness of the insulator of the samples, the permittivity of Al2O3 was extracted to be 7.6. The estimated Al2O3 properties correspond to the oxygen deficient amorphous phase of alumina.",
"author_names": [
"Evgeny R Zakirov",
"Valeriy G Kesler",
"G Yu Sidorov",
"Igor P Prosvirin",
"Anton K Gutakovsky",
"V I Vdovin"
],
"corpus_id": 145998318,
"doc_id": "145998318",
"n_citations": 10,
"n_key_citations": 0,
"score": 0,
"title": "XPS investigation of the ALD Al2O3/HgCdTe heterointerface",
"venue": "Semiconductor Science and Technology",
"year": 2019
},
{
"abstract": "Abstract During the first stages of Atomic Layer Deposition (ALD) of Al2O3 on silicon (Si) the substrate nature affects the surface chemistry, leading to an initial island growth mode. Furthermore, an interfacial zone develops between the Si surface and the dielectric, thus damaging the physical properties of the deposited structure. In this work, these two main shortcomings are investigated for the ALD of Al2O3 films on Si from TMA and H2O. The film and the interfacial zone are characterized by a complete range of techniques, including XRR, TEM, XPS, EDX and ToF SIMS. In parallel, a computational model is developed to study the initial nucleation and growth steps of the film. An induction period is experimentally evidenced and numerically reproduced, together with the island growth and coalescence phenomena. The chemical composition of the (Al, O, Si) interfacial layer is precisely analyzed to get insight in the mechanisms of its formation. We show that Si oxidation occurs during the island growth, catalyzed by the presence of Al, while it is also fed by species interdiffusion through the ALD film.",
"author_names": [
"Georgios Gakis",
"Constantin Vahlas",
"Hugues Vergnes",
"Sandrine Dourdain",
"Y Tison",
"Herve Martinez",
"Jerome Bour",
"David S Ruch",
"Andreas G Boudouvis",
"Brigitte Caussat",
"Emmanuel Scheid"
],
"corpus_id": 197633112,
"doc_id": "197633112",
"n_citations": 11,
"n_key_citations": 0,
"score": 0,
"title": "Investigation of the initial deposition steps and the interfacial layer of Atomic Layer Deposited (ALD) Al2O3 on Si",
"venue": "Applied Surface Science",
"year": 2019
},
{
"abstract": "We have characterized the interface states of Al2O3/GaN and Al2O3/AlGaN/GaN structures prepared by atomic layer deposition using the conventional and photo assisted capacitance voltage (C V) measurements. In order to control the interface states, an N2O radical treatment was applied to the GaN and AlGaN surfaces prior to the deposition of the Al2O3 layer. We observed good C V behavior and a relatively low density of interface states for the N2O radical treated Al2O3/GaN structure. To estimate the state density distributions at the Al2O3/AlGaN interface, we applied the photo assisted C V measurement to the Al2O3/AlGaN/GaN heterostructures. The present Al2O3/AlGaN structre showed higher interface state densities than the Al2O3/GaN structure. However, we found that the N2O radical treatment is effective in reducing the density of interface states at the Al2O3/GaN and Al2O3/AlGaN systems (c) 2012 WILEY VCH Verlag GmbH Co. KGaA, Weinheim)",
"author_names": [
"Yuji Hori",
"Chihoko Mizue",
"Tamotsu Hashizume"
],
"corpus_id": 98137044,
"doc_id": "98137044",
"n_citations": 30,
"n_key_citations": 0,
"score": 0,
"title": "Interface state characterization of ALD Al2O3/GaN and ALD Al2O3/AlGaN/GaN structures",
"venue": "",
"year": 2012
},
{
"abstract": "The effects of fabrication processes on the electrical properties of Al2O3/GaN structures prepared by atomic layer deposition were investigated. The annealing process at 800 degC for the formation of ohmic electrodes brought a large number of microcrystallization regions into the Al2O3 layer, causing a marked leakage in the current voltage characteristics of the Al2O3/GaN structure. The \"ohmic first\" process with a SiN protection layer was thus applied to the GaN surface. In this process, the amorphous phase in the atomic configuration of Al2O3 was maintained, leading to the sufficient suppression of leakage current at the Al2O3/GaN interface. In addition, the Al2O3/GaN structures showed good capacitance voltage characteristics, resulting in low interface state densities of less than 1x1012 cm 2 eV 1.",
"author_names": [
"Yuji Hori",
"Chihoko Mizue",
"Tamotsu Hashizume"
],
"corpus_id": 121077379,
"doc_id": "121077379",
"n_citations": 93,
"n_key_citations": 0,
"score": 1,
"title": "Process Conditions for Improvement of Electrical Properties of Al2O3/n GaN Structures Prepared by Atomic Layer Deposition",
"venue": "",
"year": 2010
},
{
"abstract": "We performed interfacial electric and electronic studies of both in situ and ex situ atomic layer deposited (ALD) Al2O3 films on InGaAs. Self aligned inversion channel metal oxide semiconductor field effect transistors (MOSFETs) with a 1 mm gate length (Lg) from the in situ sample have extrinsic drain currents (Id) of 1.8 mA/mm, transconductances (Gm) of 0.98 mS/mm, and an effective mobility (meff) of 1250 cm2/V s. MOSFETs that employ ex situ ALD Al2O3 have an Id of 0.56 mA/mm, Gm of 0.28 mS/mm, and meff of 410 cm2/V s. Synchrotron radiation photoemission reveals no AsOx residue at the Al2O3/InGaAs interface using the in situ approach, whereas some AsOx residue is detected using the ex situ method.",
"author_names": [
"Minghwei Hong",
"H W Wan",
"K Y Lin",
"Yu Cheng Chang",
"Mei-Hsin Chen",
"Yung-Hsiang Lin",
"T D Lin",
"Tun Wen Pi",
"Jueinai Kwo"
],
"corpus_id": 126380390,
"doc_id": "126380390",
"n_citations": 10,
"n_key_citations": 1,
"score": 0,
"title": "Perfecting the Al2O3/In0.53Ga0.47As interfacial electronic structure in pushing metal oxide semiconductor field effect transistor device limits using in situ atomic layer deposition",
"venue": "",
"year": 2017
},
{
"abstract": "This study compares the physical, chemical and electrical properties of Al2O3 thin films deposited on gallium polar c and nonpolar m plane GaN substrates by atomic layer deposition (ALD) Correlations were sought between the film's structure, composition, and electrical properties. The thickness of the Al2O3 films was 19.2 nm as determined from a Si witness sample by spectroscopic ellipsometry. The gate dielectric was slightly aluminum rich (Al:O=1:1.3) as measured from X ray photoelectron spectroscopy (XPS) depth profile, and the oxide semiconductor interface carbon concentration was lower on c plane GaN. The oxide's surface morphology was similar on both substrates, but was smoothest on c plane GaN as determined by atomic force microscopy (AFM) Circular capacitors (50 300 mm diameter) with Ni/Au (20/100 nm) metal contacts on top of the oxide were created by standard photolithography and e beam evaporation methods to form metal oxide semiconductor capacitors (MOSCAPs) The alumina deposited on c plane GaN showed less hysteresis (0.15 V) than on m plane GaN (0.24 V) in capacitance voltage (CV) characteristics, consistent with its better quality of this dielectric as evidenced by negligible carbon contamination and smooth oxide surface. These results demonstrate the promising potential of ALD Al2O3 on c plane GaN, but further optimization of ALD is required to realize the best properties of Al2O3 on m plane GaN. (c) 2014 WILEY VCH Verlag GmbH Co. KGaA, Weinheim)",
"author_names": [
"Daming Wei",
"Tashfin Hossain",
"Neeraj Nepal",
"Nelson Y Garces",
"Jennifer K Hite",
"Harry M Meyer",
"Charles R Eddy",
"James H Edgar"
],
"corpus_id": 97057474,
"doc_id": "97057474",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Comparison of the physical, chemical and electrical properties of ALD Al2O3 on c and m plane GaN",
"venue": "",
"year": 2014
},
{
"abstract": "Data on X ray diffraction in lanthanum diphthalocyanine pyrolysates synthesized at temperatures of 800 1800degS demonstrate the formation of an amorphous carbon phase with embedded lanthanum atoms. Low temperature pyrolysis (800 900degS) creates layered carbon structures. Due to annealing at 1000degS, carbon integrates into globules whose number of atoms is m 100. Such structures with gyration radii of Rg 0.4 0.5 nm on the order of the precursor molecule size are synthesized in the temperature range of 1000 1800degS, and are stable in terms of size and mass. In this case, their density approaches that of graphite.",
"author_names": [
"Vasiliy T Lebedev",
"A E Sovestnov",
"Vladimir I Tikhonov",
"Y P Chernenkov"
],
"corpus_id": 98929831,
"doc_id": "98929831",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Structure of the amorphous phase of pyrolisates of lanthanum diphthalocyanine according to X ray scattering data",
"venue": "Journal of Surface Investigation: X ray, Synchrotron and Neutron Techniques",
"year": 2017
},
{
"abstract": "The characteristics of the oxide layer deposited by microarc oxidation (MAO) on Al Si alloys in a silicate alkaline electrolyte are studied. The thermal conductivity of the layer at 50 120degC is determined using a special facility by the method of stationary heat flow. The thickness, the porosity, the elemental composition, the content of the amorphous phase, and the size of the crystallites in the oxide layer are determined. The results obtained are analyzed and the conditions for the lowest thermal conductivity of the oxide layer are determined.",
"author_names": [
"Natalia Y Dudareva",
"Pavel V Ivashin",
"R F Gallyamova",
"A Ya Tverdokhlebov",
"Mikhail M Krishtal"
],
"corpus_id": 232343242,
"doc_id": "232343242",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Structure and Thermophysical Properties of Oxide Layer Formed by Microarc Oxidation on AK12D Al Si Alloy",
"venue": "Metal Science and Heat Treatment",
"year": 2021
},
{
"abstract": "Atomic layer deposition (ALD) of Al2O3 was used to prepare metal oxide semiconductor (MOS) devices on two different_AlGaN/GaN heterostructures, with and without a thin GaN cap layer. Their trapping effects were evaluated by the frequency dependent conductance measurement. The trap state density decreased sharply from ~1x1012 cm 2 eV 1 at the energy of 0.27 eV to ~3x1010 cm 2 eV 1 at 0.45 eV. The low trap state density and exactly exponential dependence of the trap state time constant on the gate voltage show a good quality of the gate oxide. The trap state density in the structure with a GaN cap is about 2 3 times lower than that in the structure without a cap, which might be due to the different Al2O3/GaN and Al2O3/AlGaN interface properties. The trap state density in the structures investigated is lower than those reported for the devices with the metal organic chemical vapor deposition and Al oxidized Al2O3 gate oxide. This shows an importance of the ALD technique for the preparation of high performanc.",
"author_names": [
"Dagmar Gregusova",
"Roman Stoklas",
"Chihoko Mizue",
"Yuji Hori",
"Jozef Novak",
"Tamotsu Hashizume",
"Peter Kordos"
],
"corpus_id": 123532998,
"doc_id": "123532998",
"n_citations": 50,
"n_key_citations": 1,
"score": 0,
"title": "Trap states in AlGaN/GaN metal oxide semiconductor structures with Al2O3 prepared by atomic layer deposition",
"venue": "",
"year": 2010
},
{
"abstract": "Patterned layers of Al2O3 prepared by atomic layer deposition (ALD) are used to produce structures of alternating polarity (c plane orientation) of GaN on Ga polar GaN epilayers. Annealing prior to epitaxial growth allows the amorphous ALD layers to attain sufficient crystallinity, which enables N polar GaN growth over the annealed ALD Al2O3 and Ga polar growth over the bare substrate. Transmission electron microscopy and electron channeling contrast imaging were carried out to characterize the structural nature of the material and confirm crystallinity. ALD Al2O3 may be suitable for fabricating novel variable polarity devices, particularly where growth on native, Ga polar GaN substrates is beneficial.",
"author_names": [
"Jennifer K Hite",
"Nelson Y Garces",
"Ramasis Goswami",
"Michael A Mastro",
"Fritz J Kub",
"Charles R Eddy"
],
"corpus_id": 95940439,
"doc_id": "95940439",
"n_citations": 16,
"n_key_citations": 0,
"score": 0,
"title": "Selective switching of GaN polarity on Ga polar GaN using atomic layer deposited Al2O3",
"venue": "",
"year": 2014
}
] |
Semiconductor laser synchronization | [
{
"abstract": "Abstract The cluster synchronization properties of 12 different networks that consist of five semiconductor lasers (SLs) are systematically investigated through theoretical analysis and numerical simulation. The emergence of clusters in different networks is analytically predicted, and then numerically proved in SL networks. The synchronization properties between each pair of SL nodes in a network are quantified by the zero lag cross correlation coefficient of laser intensities. The impacts of injection strength and bias current on the synchronization quality are investigated, the robustness of clusters against noise is also considered. All the expected clusters are successfully obtained in the simulation and are robust to noise. However, for some networks, different clusters may also emerge with the variation of parameters. In addition, for most networks considered in this paper, the small difference in topologies can bring about tremendous change in synchronized clusters or the synchronization properties of clusters, but for other networks no obvious change can be observed. Moreover, the synchronization properties between nodes from different clusters are also considered. The numerical results not only validate the availability of the adopted analytical method, but also shed some light on possible applications of synchronization control or tolerance of connection failure within networks of SLs.",
"author_names": [
"Yanan Han",
"Shuiying Xiang",
"Liyue Zhang"
],
"corpus_id": 145887813,
"doc_id": "145887813",
"n_citations": 3,
"n_key_citations": 0,
"score": 1,
"title": "Cluster synchronization in mutually coupled semiconductor laser networks with different topologies",
"venue": "Optics Communications",
"year": 2019
},
{
"abstract": "A new secure key distribution scheme based on the dynamic chaos synchronization of two cascaded semiconductor laser systems (CSLSs) subject to common chaotic injection and random phase modulated optical feedback is demonstrated. In this scheme, Alice and Bob adopt two independent random sequences to control the phase modulators of CSLSs, which induces a dynamic perturbation to the chaos synchronization. We thoroughly investigate the chaos synchronization performance under different phase shift conditions with cross correlation function, and systematically discuss the feasibility and security of the system. The results show that, with proper injection and feedback strength, the correlation coefficient gap between phase shift match and mismatch is clear and robust to the parameter mismatches in the CSLSs and those between the two CSLSs. Based on this, high quality key distribution can be performed by picking out the identical random bits from the two independent random sequences according to the computational correlation. Moreover, the investigations on the information theoretic security and rate of the key distribution show that the security of the key distribution scheme can be further enhanced by properly increasing the number of layers in the CSLSs or employing high order modulation format.",
"author_names": [
"Chenpeng Xue",
"Ning Jiang",
"Yunxin Lv",
"Kun Qiu"
],
"corpus_id": 33038255,
"doc_id": "33038255",
"n_citations": 22,
"n_key_citations": 0,
"score": 0,
"title": "Secure Key Distribution Based on Dynamic Chaos Synchronization of Cascaded Semiconductor Laser Systems",
"venue": "IEEE Transactions on Communications",
"year": 2017
},
{
"abstract": "Langevin noise leads to inhibition of the temporal synchronization of the pulse oscillations from a gain switched multimode semiconductor laser, resulting in the power reduction in optical beat detection. In this paper, the degree of the temporal synchronization of the pulse oscillations was examined by numerically estimating the output energy in THz time domain spectroscopy (THz TDS) using multimode semiconductor laser rate equations that include Langevin noise. The degree was estimated to be 95.5% from the ratio of the averaged THz TDS output energy for the case where Langevin noise was included to that for when Langevin noise was excluded. Therefore, a gain switched multimode semiconductor laser can be regarded as equivalent to optical pulses oscillating simultaneously in all modes in actual applications including optical beat detection.",
"author_names": [
"Kenji Wada",
"Naoaki Kitagawa",
"Tetsuya Matsuyama"
],
"corpus_id": 7638628,
"doc_id": "7638628",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "The Degree of Temporal Synchronization of the Pulse Oscillations from a Gain Switched Multimode Semiconductor Laser",
"venue": "Materials",
"year": 2017
},
{
"abstract": "Nonlinear dynamics of a semiconductor laser subjected optical feedback observed numerically. The investigation performed based on numerical simulation of Lang Kobayashi time delay rate equations over wide range of optical feedback strength. The results show that under small, moderate and high optical feedback strength semiconductor laser output power goes different dynamical regimes involving steady state, periodic, mixed modes and chaotic spiking. These dynamics analyzed by time series and their FFt power spectrum with phase space trajectory. The bifurcation diagram is drawn as a function of optical feedback strength. Chaos synchronization in unidirectional coupling scheme numerically presented.",
"author_names": [
"Nasraldien A Eashag Saeed",
"Sora F Abdalah",
"Abdelmoneim Mohamed Awadelgied",
"Kais A Al Naimee"
],
"corpus_id": 55805039,
"doc_id": "55805039",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "SPILKING GENERATION AND SYNCHRONIZATION IN SEMICONDUCTOR LASER BY MEANS OF OPTICAL FEEDBACK",
"venue": "",
"year": 2017
},
{
"abstract": "Abstract We investigate the synchronization in coupled time delayed semiconductor laser models without and under the influence of external noise sources. The synchronization and its robustness are observed by mean synchronization error and the effect of parameter mismatch respectively. A communication scheme is introduced based on symmetrical encryption and decryption method in the frame of coupled synchronized lasers with optical feedback. The scheme is effective irrespective of the nature and dynamics of the transmitted signal. The security of the scheme is verified by the effect of relative parameter mismatch, key sensitivity frequency and cross correlation analysis. Numerical results support the proposed analysis.",
"author_names": [
"Thang Manh Hoang",
"Sanjay Kumar Palit",
"Sayan Mukherjee",
"Santo Banerjee"
],
"corpus_id": 114914505,
"doc_id": "114914505",
"n_citations": 10,
"n_key_citations": 0,
"score": 0,
"title": "Synchronization and secure communication in time delayed semiconductor laser systems",
"venue": "",
"year": 2016
},
{
"abstract": "A model of a planar semiconductor multi channel laser is developed. In this model two dimensional (2D) Bragg mirror structures are used for synchronizing radiation of multiple laser channels. Coupling of longitudinal and transverse waves can be mentioned as the distinguishing feature of these structures. Synchronization of 20 laser channels is demonstrated with a semi classical approach based on Maxwell Bloch equations.",
"author_names": [
"V R Baryshev",
"Naum S Ginzburg"
],
"corpus_id": 113924170,
"doc_id": "113924170",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Synchronization of semiconductor laser arrays with 2D Bragg structures",
"venue": "",
"year": 2016
},
{
"abstract": "Two multi semiconductor laser (SL) topologies, based on mutually coupled semiconductor lasers representing a startype and a mesh type network are evaluated in terms of their synchrony potential and their sensitivity towards critical SLs' intrinsic and operational parameters. The coupling topology, the coupling conditions and the values of key SL parameters determine the type of dynamics of the emitted optical signals. The number of nodes and the detuning in their fundamental properties have been assessed to be decisive in terms of efficiency and quality of synchronized outputs, as wells as for the overall dynamical map of the network. Our investigation mainly focuses on discrepancies in SL parameter values and their effect on the efficiency of synchronized dynamics. This type of investigation will provide preliminary guidelines on building experimentally large scale networks of coupled SLs under various coupling matrices that could support optical sensing or cryptographic applications.",
"author_names": [
"Michail Bourmpos",
"Apostolos Argyris",
"Dimitris Syvridis"
],
"corpus_id": 109056560,
"doc_id": "109056560",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Coupled semiconductor laser network topologies for efficient synchronization",
"venue": "Photonics West Optoelectronic Materials and Devices",
"year": 2015
},
{
"abstract": "Optical chaos communication has advantages of high speed and long transmission distance. Unfortunately, the key space of the traditional transceiver, i.e. semiconductor laser with mirror feedback, is limited due to the time delay signature. In this paper, we propose and numerically demonstrate a key space enhancement by using semiconductor laser with optical feedback from a chirped fiber Bragg grating (FBG) The chirped FBG feedback can make feedback delay a key parameter by eliminating the time delay signature. Moreover, the grating dispersion and center frequency can also be used as new keys. As a result, the dimension of key space is increased. By taking a bidirectional communication scheme as an example, numerical results show that the key space is raised by 244 times as against mirror feedback with a data rate of 2.5 Gb/s and a coupling strength of 0.447. As the coupling strength decreases, the key space increases due to the fact that chaos synchronization becomes more sensitive to parameter mismatch.",
"author_names": [
"Da Wang",
"Louis S Wang",
"Y Y Guo",
"Yu Cheng Wang",
"A B Wang"
],
"corpus_id": 73418966,
"doc_id": "73418966",
"n_citations": 20,
"n_key_citations": 1,
"score": 0,
"title": "Key space enhancement of optical chaos secure communication: chirped FBG feedback semiconductor laser.",
"venue": "Optics express",
"year": 2019
},
{
"abstract": "We discuss a model of anticipated synchronization of two distributed feedback lasers (DFB) with passive dispersive reflector. The influence of passive dispersive reflector parameters on the anticipated synchronization is discussed. The conditions for delayed, perfect and anticipated synchronizations are explored in detail.",
"author_names": [
"Nellu Ciobanu",
"Spiridon Rusu",
"Vasile Tronciu"
],
"corpus_id": 113096212,
"doc_id": "113096212",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Anticipated Synchronization of Passive Dispersive Reflector Semiconductor Laser",
"venue": "",
"year": 2016
},
{
"abstract": "In this paper, synchronization of multiple chaotic semiconductor lasers is achieved by appealing to complex system theory. In particular, we consider dynamical networks composed by semiconductor laser, as interconnected nodes, where the interaction in the networks are defined by coupling the first state of each node. An interest case is synchronized with master slave configuration in star topology. Nodes of these networks are modeled for the laser and simulate by Matlab. These results are applicable to private communication. Keywords Synchronization, chaotic laser, network.",
"author_names": [
"Rosa Martha Lopez-Gutierrez",
"L Cardoza-Avendano",
"H Cervantes-de Avila",
"J A Michel-Macarty",
"Cesar Cruz-Hernandez",
"Adrian Arellano-Delgado",
"R Carmona-Rodriguez"
],
"corpus_id": 21196453,
"doc_id": "21196453",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Synchronization of Semiconductor Laser Networks",
"venue": "",
"year": 2015
}
] |
Diluted ferromagnetic semiconductor (Zn, Mn) P with decoupled charge and spin doping | [
{
"abstract": "We report the discovery of a diluted magnetic semiconductor, Li(Zn,Mn)P, in which charge and spin are introduced independently via lithium off stoichiometry and the isovalent substitution of Mn2+ for Zn2+ respectively. Isostructural to (Ga,Mn)As, Li(Zn, Mn) P was found to be a p type ferromagnetic semiconductor with excess lithium providing charge doping. First principles calculations indicate that excess Li is favored to partially occupy the Zn site, leading to hole doping. Ferromagnetism with Curie temperature up to 34 K is achieved while the system still shows semiconducting transport behavior.",
"author_names": [
"Zheng Deng",
"Kan Zhao",
"",
"J L Zhu",
"Xiancheng Wang",
"Xiaodong Li",
"Q Q Liu",
"R C Yu",
"Tatsuo Goko",
"Benjamin A Frandsen",
"L Liu",
"Jinsong Zhang",
"Yayu Wang",
"Fanlong Ning",
"Sadamichi Maekawa",
"Yasutomo J Uemura"
],
"corpus_id": 52860127,
"doc_id": "52860127",
"n_citations": 50,
"n_key_citations": 0,
"score": 1,
"title": "Diluted ferromagnetic semiconductor Li(Zn,Mn)P with decoupled charge and spin doping",
"venue": "",
"year": 2013
},
{
"abstract": "We report a new diluted ferromagnetic semiconductor Li1+y(Cd,Mn)P, wherein carrier is doped via excess Li while spin is doped by isovalence substitution of Mn2+ into Cd2+ The extended Cd 4d orbitals lead to more itinerant characters of Li1+y(Cd,Mn)P than that of analogous Li1+y(Zn,Mn)P. A higher Curie temperature of 45 K than that for Li1+y(Zn,Mn)P is obtained in Li1+y(Cd,Mn)P polycrystalline samples by Arrott plot technique. The p type carriers are determined by Hall effect measurements. The first principle calculations and X ray diffraction measurements indicate that occupation of excess Li is at Cd sites rather than the interstitial site. Consequently holes are doped by excess Li substitution. More interestingly Li1+y(Cd,Mn)P shows a very low coercive field <100 Oe) and giant negative magnetoresistance ~80% in ferromagnetic state that will benefit potential spintronics applications.",
"author_names": [
"W Han",
"B J Chen",
"Bo Gu",
"G Q Zhao",
"S H Yu",
"Xue Cai Wang",
"Q Q Liu",
"Zheng Deng",
"Wei Min Li",
"J F Zhao",
"Lipeng Cao",
"Yan Peng",
"X Shen",
"X Zhu",
"R C Yu",
"Sadamichi Maekawa",
"Yasutomo J Uemura",
"Changqing Jin"
],
"corpus_id": 155104496,
"doc_id": "155104496",
"n_citations": 6,
"n_key_citations": 0,
"score": 0,
"title": "Li(Cd,Mn)P: a new cadmium based diluted ferromagnetic semiconductor with independent spin charge doping",
"venue": "Scientific Reports",
"year": 2019
},
{
"abstract": "Here, we report the successful synthesis of a spin and charge decoupled diluted magnetic semiconductor (DMS) (Ca,Na)(Zn,Mn)2As2, crystallizing into the hexagonal CaAl2Si2 structure. The compound shows a ferromagnetic transition with a Curie temperature up to 33 K with 10% Na doping, which gives rise to carrier density of np 1020 cm 3. The new DMS is a soft magnetic material with HC 400 Oe. The anomalous Hall effect is observed below the ferromagnetic ordering temperature. With increasing Mn doping, ferromagnetic order is accompanied by an interaction between the local spin and mobile charge, giving rise to a minimum in resistivity at low temperatures and localizing the conduction electrons. The system provides an ideal platform for studying the interaction of the local spins and conduction electrons.",
"author_names": [
"Kun Zhao",
"Bijuan Chen",
"Zheng Deng",
"W Han",
"Guijuan Zhao",
"J L Zhu",
"Q Q Liu",
"Xiongjun Wang",
"Benjamin A Frandsen",
"Lan-xiao Liu",
"Sky Cheung",
"Fanlong Ning",
"Timothy J S Munsie",
"Teresa Medina",
"Graeme M Luke",
"Jeremy P Carlo",
"J Munevar",
"G M Zhang",
"Yasutomo J Uemura",
"Changqing Jin"
],
"corpus_id": 52846934,
"doc_id": "52846934",
"n_citations": 16,
"n_key_citations": 0,
"score": 0,
"title": "(Ca,Na)(Zn,Mn)2As2: A new spin and charge doping decoupled diluted ferromagnetic semiconductor",
"venue": "",
"year": 2014
},
{
"abstract": "Abstract First principles calculations were performed to study electronic structures and magnetic properties of diluted magnetic semiconductors Li(Zn,TM)N (TM V, Cr, Mn, Fe, Co and Ni) All TM doped LiZnN systems were magnetic, Cr, Mn and Fe doped LiZnN preferred anti ferromagnetic states while V, Co and Ni doped LiZnN systems preferred ferromagnetic states. In contrast, V/Li, Mn/Li and Ni/Li codoped LiZnN preferred ferromagnetic couplings between the TM atoms. The magnetic moments mainly came from the TM 3d orbitals. For Cr/Li, Fe/Li and Co/Li codoped LiZnN, anti ferromagnetic states were more stable. Hence off stoichiometry of Li is very essential for the preparation of ferromagnetic LiZnN materials. These results may provide theoretical guidance for further experimental research.",
"author_names": [
"Y Cui",
"J G Zhu",
"Hualong Tao",
"Su Mei Liu",
"Yuezu Lv",
"M He",
"Bo Song",
"Yong-Gang Chen",
"Zhihua Zhang"
],
"corpus_id": 139169626,
"doc_id": "139169626",
"n_citations": 9,
"n_key_citations": 0,
"score": 0,
"title": "Magnetic properties of diluted magnetic semiconductors Li(Zn,TM)N with decoupled charge and spin doping (TM: V, Cr, Mn, Fe, Co and Ni)",
"venue": "Computational Materials Science",
"year": 2019
},
{
"abstract": "Here we report the successful synthesis of a spin &charge decoupled diluted magnetic semiconductor (Ca,Na)(Zn,Mn)2As2, crystallizing into the hexagonal CaAl2Si2 structure. The compound shows a ferromagnetic transition with a Curie temperature up to 33 K with 10% Na doping, which gives rise to carrier density of np~10^20 cm^ 3. The new DMS is a soft magnetic material with HC<400 Oe. The anomalous Hall effect is observed below the ferromagnetic ordering temperature. With increasing Mn doping, ferromagnetic order is accompanied by an interaction between the local spin and mobile charge, giving rise to a minimum in resistivity at low temperatures and localizing the conduction electrons. The system provides an ideal platform for studying the interaction of the local spins and conduction electrons.",
"author_names": [
"Kan Zhao",
"B J Chen",
"Zheng Deng",
"W Han",
"",
"J L Zhu",
"Q Q Liu",
"Xiao Chen Wang",
"Benjamin A Frandsen",
"L Liu",
"Sky Cheung",
"Fanlong Ning",
"Timothy J S Munsie",
"Teresa Medina",
"Graeme M Luke",
"Jeremy P Carlo",
"J Munevar",
"G M Zhang",
"Yasutomo J Uemura",
"Changqing Jin"
],
"corpus_id": 118561375,
"doc_id": "118561375",
"n_citations": 22,
"n_key_citations": 0,
"score": 0,
"title": "(Ca,Na)(Zn,Mn)2As2: a new spin&charge doping decoupled diluted ferromagnetic semiconductor with hexagonal CaAl2Si2 structure",
"venue": "",
"year": 2014
},
{
"abstract": "We report the successful synthesis and characterization of a new type I II V bulk form diluted magnetic semiconductor (DMS) Li(Zn,Mn,Cu)As, in which charge and spin doping are decoupled via (Cu,Zn) and (Mn,Zn) substitution at the same Zn sites. Ferromagnetic transition temperature up to ~33 K has been observed with a coercive field ~40 Oe for the 12.5% doping level. mSR measurements confirmed that the magnetic volume fraction reaches nearly 100% at 2 K, and the mechanism responsible for the ferromagnetic interaction in this system is the same as other bulk form DMSs.",
"author_names": [
"S L Guo",
"Y Zhao",
"Huiyuan Man",
"Cui Ding",
"Xin Gong",
"Guoxiang Zhi",
"Licheng Fu",
"Y Gu",
"Benjamin A Frandsen",
"L Liu",
"Sky Cheung",
"Timothy J S Munsie",
"M N Wilson",
"Y P Cai",
"Graeme M Luke",
"Yasutomo J Uemura",
"Fanlong Ning"
],
"corpus_id": 46793114,
"doc_id": "46793114",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "mSR investigation of a new diluted magnetic semiconductor Li(Zn,Mn,Cu)As with Mn and Cu codoping at the same Zn sites.",
"venue": "Journal of physics. Condensed matter an Institute of Physics journal",
"year": 2016
},
{
"abstract": "We report the discovery of a new fluoride arsenide bulk diluted magnetic semiconductor (Ba,K)F(Zn,Mn)As with the tetragonal ZrCuSiAs type structure which is identical to that of the \"1111\" iron based superconductors. The joint hole doping via (Ba,K) substitution spin doping via (Zn,Mn) substitution results in ferromagnetic order with Curie temperature up to 30 K and demonstrates that the ferromagnetic interactions between the localized spins are mediated by the carriers. Muon spin relaxation measurements confirm the intrinsic nature of the long range magnetic order in the entire volume in the ferromagnetic phase. This is the first time that a diluted magnetic semiconductor with decoupled spin and charge doping is achieved in a fluoride compound. Comparing to the isostructure oxide counterpart of LaOZnSb, the fluoride DMS (Ba,K)F(Zn,Mn)As shows much improved semiconductive behavior that would be benefit for further application developments.",
"author_names": [
"Bijuan Chen",
"Zheng Deng",
"Wenmin Li",
"Moran Gao",
"Qing-qing Liu",
"Changzhi Gu",
"Fengxia Hu",
"Baogen Shen",
"Benjamin A Frandsen",
"Sky Cheung",
"Liu Lian",
"Yasutomo J Uemura",
"Cui Ding",
"Shengli Guo",
"Fanlong Ning",
"Timothy J S Munsie",
"Murray N Wilson",
"Yipeng Cai",
"Graeme Luke",
"Zurab Guguchia",
"Shingo Yonezawa",
"Zhi Li",
"Changqing Jin"
],
"corpus_id": 5045055,
"doc_id": "5045055",
"n_citations": 12,
"n_key_citations": 0,
"score": 0,
"title": "New Fluoride arsenide Diluted Magnetic Semiconductor (Ba,K)F(Zn,Mn)As with Independent Spin and Charge Doping",
"venue": "Scientific reports",
"year": 2016
},
{
"abstract": "The electronic structure and the magnetic properties of a new diluted magnetic semiconductor have been investigated, using first principles calculations within the Perdew Burke Ernzerhof generalized gradient approximation. Compound is a type structure semiconductor with a direct bandgap of 0.57 eV at the point. With spins doped via isovalent (Zn, Mn) substitutions, the system prefers the antiferromagnetic ground state, resulting from the Mn Mn superexchange interactions. Via off stoichiometry (Sr, Na) substitutions, holes are introduced into the system, resulting in the ferromagnetic spin responses for Mn Mn pairs, except for the nearest neighboring Mn Mn pair. Based on our calculations, the ferromagnetism in the II II V based diluted magnetic semiconductor originates from Zener's p d exchange interactions between localized Mn spins and itinerant holes mediated by As atoms.",
"author_names": [
"Jun-tao Yang",
"S J Luo",
"Yong-Chen Xiong"
],
"corpus_id": 97617927,
"doc_id": "97617927",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Magnetic mechanism investigations on the ferromagnetism of (Sr,Na)(Zn,Mn)2As2 with decoupled charge and spin doping",
"venue": "",
"year": 2016
},
{
"abstract": "The electronic structure and magnetism of a series of 111 type diluted magnetic semiconductors Li(Zn,TM)P (TM V, Cr, Mn, Fe, Co, and Ni) are investigated on the basis of density functional theory. Our results indicate that V Cr Mn and Fe doped LiZnP are magnetic while Co and Ni doped LiZnP systems show no magnetisms. But all TM doped LiZnP systems prefer antiferromagnetic behavior by magnetic coupling calculations. In contrast, V/Li and Cr/Li codoped LiZnP prefer ferromagnetic ordering, and Mn/Li Fe/Li and Co/Li codoped LiZnP display antiferromagnetic spin ordering. Hence, Li dopant is very vital for the ferromagnetic formation of Li(Zn,TM)P materials. It is revealed that the magnetic moments come mainly from the TM 3d orbitals. The ferromagnetic coupling between the TM atoms is explained by through bond spin polarization. Our work demonstrates that the magnetic properties of Li(Zn,TM)P can be mediated by doping different TM atoms. These results may provide theoretical guidance for further experimental research on DMS.",
"author_names": [
"Hualong Tao",
"Mengxia Wang",
"Zhihua Zhang",
"M He",
"Bo Song"
],
"corpus_id": 126341452,
"doc_id": "126341452",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Effects of Transition Metal (TM V, Cr, Mn, Fe, Co, and Ni) Elements on Magnetic Mechanism of LiZnP with Decoupled Charge and Spin Doping",
"venue": "",
"year": 2017
},
{
"abstract": "By using the density functional theory within Perdew Burke Ernzerh of generalized gradient approximation, the electronic structures and magnetic properties of system were investigated. Undoped compound is a semiconductor crystallized with a hexagonal type structure. After local moments doping via isovalent (Cd2+ Mn2+ substitutions, is antiferromagnetic system, which is attributed to the superexchange interactions between the Mn2+ ions in the high spin state. With itinerant holes introduced via off stoichiometry (Ba2+ substitutions, system (except for the system doped with the most nearest neighbor Mn Mn pair) changes from antiferromagnetic to ferromagnetic, resulted from the indirect exchange interactions based on p d exchange coupling between As and Mn orbitals. Moreover, hypothetical supercells with different lattice parameters under mechanical compression and expansion were calculated to study the effect of itinerant holes on the Curie temperature. Our results reveal that the system with small lattice has more holes amount and better holes mobility, leading to a higher Curie temperature for the type structure DMSs.",
"author_names": [
"Jun-tao Yang",
"S J Luo",
"Zhenxiang Cheng",
"Xiaotian Wang",
"Yong-Chen Xiong",
"Laref Amel"
],
"corpus_id": 100162696,
"doc_id": "100162696",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Electronic structures and magnetic properties of a II II V based diluted magnetic semiconductor Ba 1 x K x (Cd 1 y Mn y 2 As 2 with decoupled charge and spin doping",
"venue": "",
"year": 2016
}
] |
Operation of a silicon quantum processor unit cell above one kelvin | [
{
"abstract": "Quantum computers are expected to outperform conventional computers in several important applications, from molecular simulation to search algorithms, once they can be scaled up to large numbers typically millions of quantum bits (qubits) 1 3 For most solid state qubit technologies for example, those using superconducting circuits or semiconductor spins scaling poses a considerable challenge because every additional qubit increases the heat generated, whereas the cooling power of dilution refrigerators is severely limited at their operating temperature (less than 100 millikelvin) 4 6 Here we demonstrate the operation of a scalable silicon quantum processor unit cell comprising two qubits confined to quantum dots at about 1.5 kelvin. We achieve this by isolating the quantum dots from the electron reservoir, and then initializing and reading the qubits solely via tunnelling of electrons between the two quantum dots 7 9 We coherently control the qubits using electrically driven spin resonance 10 11 in isotopically enriched silicon 12 28 Si, attaining single qubit gate fidelities of 98.6 per cent and a coherence time of 2 microseconds during 'hot' operation, comparable to those of spin qubits in natural silicon at millikelvin temperatures 13 16 Furthermore, we show that the unit cell can be operated at magnetic fields as low as 0.1 tesla, corresponding to a qubit control frequency of 3.5 gigahertz, where the qubit energy is well below the thermal energy. The unit cell constitutes the core building block of a full scale silicon quantum computer and satisfies layout constraints required by error correction architectures 8 17 Our work indicates that a spin based quantum computer could be operated at increased temperatures in a simple pumped 4 He system (which provides cooling power orders of magnitude higher than that of dilution refrigerators) thus potentially enabling the integration of classical control electronics with the qubit array 18 19 A scalable silicon quantum processor unit cell made of two qubits confined to quantum dots operates at about 1.5 K, achieving 98.6% single qubit gate fidelities and a 2 ms coherence time.",
"author_names": [
"C H Yang",
"Ross C C Leon",
"J C C Hwang",
"Andre Saraiva",
"Tuomo Tanttu",
"W Huang",
"Julien Camirand Lemyre",
"K W Chan",
"K Y Tan",
"Fay E Hudson",
"Kohei M Itoh",
"Andrea Morello",
"Michel Pioro-Ladriere",
"Arne Laucht",
"Andrew S Dzurak"
],
"corpus_id": 215775496,
"doc_id": "215775496",
"n_citations": 74,
"n_key_citations": 2,
"score": 1,
"title": "Operation of a silicon quantum processor unit cell above one kelvin",
"venue": "Nature",
"year": 2020
},
{
"abstract": "Quantum computers are expected to outperform conventional computers for a range of important problems, from molecular simulation to search algorithms, once they can be scaled up to large numbers of quantum bits (qubits) typically millions. For most solid state qubit technologies, e.g. those using superconducting circuits or semiconductor spins, scaling poses a significant challenge as every additional qubit increases the heat generated, while the cooling power of dilution refrigerators is severely limited at their operating temperature below 100 mK. Here we demonstrate operation of a scalable silicon quantum processor unit cell, comprising two qubits confined to quantum dots (QDs) at \\sim$1.5 Kelvin. We achieve this by isolating the QDs from the electron reservoir, initialising and reading the qubits solely via tunnelling of electrons between the two QDs. We coherently control the qubits using electrically driven spin resonance (EDSR) in isotopically enriched silicon {28}$Si, attaining single qubit gate fidelities of 98.6% and coherence time $T_2^ 2$\\mu$s during `hot' operation, comparable to those of spin qubits in natural silicon at millikelvin temperatures. Furthermore, we show that the unit cell can be operated at magnetic fields as low as 0.1 T, corresponding to a qubit control frequency of 3.5 GHz, where the qubit energy is well below the thermal energy. The unit cell constitutes the core building block of a full scale silicon quantum computer, and satisfies layout constraints required by error correction architectures. Our work indicates that a spin based quantum computer could be operated at elevated temperatures in a simple pumped ^4$He system, offering orders of magnitude higher cooling power than dilution refrigerators, potentially enabling classical control electronics to be integrated with the qubit array.",
"author_names": [
"C H Yang",
"Ross C C Leon",
"J C C Hwang",
"Andre Saraiva",
"Tuomo Tanttu",
"W Huang",
"Julien Camirand Lemyre",
"K W Chan",
"K Y Tan",
"Fay E Hudson",
"Kohei M Itoh",
"Andrea Morello",
"Michel Pioro-Ladriere",
"Arne Laucht",
"Andrew S Dzurak"
],
"corpus_id": 119520750,
"doc_id": "119520750",
"n_citations": 39,
"n_key_citations": 0,
"score": 0,
"title": "Silicon quantum processor unit cell operation above one Kelvin.",
"venue": "",
"year": 2019
},
{
"abstract": "The researchers' proof of concept quantum processor unit cell, on a silicon chip, works at 1.5 Kelvin 15 times warmer than the main competing chip based technology being developed by Google, IBM, and others, which uses superconducting qubits. \"This is still very cold, but is a temperature that can be achieved using just a few thousand dollars' worth of refrigeration, rather than the millions of dollars needed to cool chips to 0.1 Kelvin,\" explains Dzurak.",
"author_names": [
"Andrew S Dzurak"
],
"corpus_id": 215776123,
"doc_id": "215776123",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Hot qubits break one of the biggest constraints to practical quantum computers",
"venue": "",
"year": 2020
},
{
"abstract": "Spins confined in Metal Oxide Silicon (MOS) quantum dot devices are promising qubits in a quantum processor, demonstrating long coherence times, a large valley splitting, and coherent interactions with donor qubits. Furthermore, the mature fabrication infrastructure of the CMOS industry offers a tantalizing roadmap towards scaling to extremely large quantum systems on a single silicon chip. Despite the incredible advances in materials and fabrication developed by the classical CMOS industry and continued by the silicon quantum electronics community, many challenges remain in building a silicon quantum processor. One of the biggest challenges impeding the scaling of large quantum dot systems is the presence of disorder and shallow electron traps at the Si/SiO2 interface. The purpose of this thesis is to illuminate mechanisms of disorder at the Si/SiO2 interface relevant to quantum dot devices, develop a framework for understanding and quantifying shallow electron traps in terms of electron spin resonance and transport measurements, and to pave a path forward for scaling MOS quantum dot devices. This thesis is organized into three sections: first, we develop a fabrication process in silicon MOSFETs yielding a low disorder Si/SiO2 interface in order to leverage this process as a platform for fabricating low disorder quantum dot devices. One of the challenges in working with silicon oxide is that high energy processes and mobile ionic contamination during the fabrication process can create electron traps and disorder at the Si/SiO2 interface. Using the low temperature (4.2 K) electron mobility as a proxy for the Si/SiO2 interface quality, we study the effect of various processing parameters on the Si/SiO2 interface disorder and ultimately arrive at a fully optimized process yielding the highest reported mobility (23,000 cm/Vs) thin oxide =30 nm) silicon MOSFET. Secondly, we study the annealing of shallow electron traps created by electronbeam (e beam) lithography. E beam lithography is a necessary tool in defining nanoiii scale electrostatic gates which define the quantum dot potential, but the high energy electrons and photons created in the process create electron traps at the interface. We directly probe shallow electron traps using electron spin resonance (ESR) and demonstrate that 1) a standard forming gas anneal is sufficient to passivate electron traps created by the e beam exposure, and 2) that our lowest temperature ESR measurements agree with transport measurements of the devices' percolation threshold, demonstrating agreement between two independent methods of characterizing the Si/SiO2 interface. Finally, leveraging the above process optimizations, we fabricate and characterize a low disorder double quantum dot device. We demonstrate agreement between the dots' charging energy and lithographic size, concluding that our dots are lithographically defined and not dominated by random disorder. Charge sensing measurements indicate regular quantum dot transitions over a wide parameter range down to the single electron regime, with evidence of few defects in the vicinity of the quantum dots, and the controllable formation of a quantum double dot. Noise spectroscopy measurements of the dot indicate a 1/f like power spectral density that is comparable in magnitude to other Si quantum dot devices measured at 300 mK. Finally, magneto spectroscopy measurements of the first and second electron transitions yield a valley splitting of 110+ 26 meV, large enough to support high fidelity spin selective operations. With this work, we demonstrate a method of fabricating low disorder, highmobility silicon MOSFETs, a framework for studying disorder in quantum dot devices in the low electron density regime, and a promising platform for MOS qubits in a lowdisorder quantum dot device architecture.",
"author_names": [
"Jin-Sung Kim"
],
"corpus_id": 198388130,
"doc_id": "198388130",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Development and Characterization of Low Disorder Metal Oxide Silicon Quantum Dot Devices",
"venue": "",
"year": 2018
},
{
"abstract": "Even the quantum simulation of an apparently simple molecule such as Fe2S2 requires a considerable number of qubits of the order of 106, while more complex molecules such as alanine (C3H7NO2) require about a hundred times more. In order to assess such a multimillion scale of identical qubits and control lines, the silicon platform seems to be one of the most indicated routes as it naturally provides, together with qubit functionalities, the capability of nanometric, serial, and industrial quality fabrication. The scaling trend of microelectronic devices predicting that computing power would double every 2 years, known as Moore's law, according to the new slope set after the 32 nm node of 2009, suggests that the technology roadmap will achieve the 3 nm manufacturability limit proposed by Kelly around 2020. Today, circuital quantum information processing architectures are predicted to take advantage from the scalability ensured by silicon technology. However, the maximum amount of quantum information per unit surface that can be stored in silicon based qubits and the consequent space constraints on qubit operations have never been addressed so far. This represents one of the key parameters toward the implementation of quantum error correction for fault tolerant quantum information processing and its dependence on the features of the technology node. The maximum quantum information per unit surface virtually storable and controllable in the compact exchange only silicon double quantum dot qubit architecture is expressed as a function of the complementary metal oxide semiconductor technology node, so the size scale optimizing both physical qubit operation time and quantum error correction requirements is assessed by reviewing the physical and technological constraints. According to the requirements imposed by the quantum error correction method and the constraints given by the typical strength of the exchange coupling, we determine the workable operation frequency range of a silicon complementary metal oxide semiconductor quantum processor to be within 1 and 100 GHz. Such constraint limits the feasibility of fault tolerant quantum information processing with complementary metal oxide semiconductor technology only to the most advanced nodes. The compatibility with classical complementary metal oxide semiconductor control circuitry is discussed, focusing on the cryogenic complementary metal oxide semiconductor operation required to bring the classical controller as close as possible to the quantum processor and to enable interfacing thousands of qubits on the same chip via time division, frequency division, and space division multiplexing. The operation time range prospected for cryogenic control electronics is found to be compatible with the operation time expected for qubits. By combining the forecast of the development of scaled technology nodes with operation time and classical circuitry constraints, we derive a maximum quantum information density for logical qubits of 2.8 and 4 Mqb/cm2 for the 10 and 7 nm technology nodes, respectively, for the Steane code. The density is one and two orders of magnitude less for surface codes and for concatenated codes, respectively. Such values provide a benchmark for the development of fault tolerant quantum algorithms by circuital quantum information based on silicon platforms and a guideline for other technologies in general.",
"author_names": [
"Davide Rotta",
"Fabio Sebastiano",
"Edoardo Charbon",
"Enrico Prati"
],
"corpus_id": 118885880,
"doc_id": "118885880",
"n_citations": 22,
"n_key_citations": 2,
"score": 0,
"title": "Quantum information density scaling and qubit operation time constraints of CMOS silicon based quantum computer architectures",
"venue": "",
"year": 2017
},
{
"abstract": "Quantum computation requires many qubits that can be coherently controlled and coupled to each other 1 Qubits that are defined using lithographic techniques have been suggested to enable the development of scalable quantum systems because they can be implemented using semiconductor fabrication technology 2 5 However, leading solid state approaches function only at temperatures below 100 millikelvin, where cooling power is extremely limited, and this severely affects the prospects of practical quantum computation. Recent studies of electron spins in silicon have made progress towards a platform that can be operated at higher temperatures by demonstrating long spin lifetimes 6 gate based spin readout 7 and coherent single spin control 8 However, a high temperature two qubit logic gate has not yet been demonstrated. Here we show that silicon quantum dots can have sufficient thermal robustness to enable the execution of a universal gate set at temperatures greater than one kelvin. We obtain single qubit control via electron spin resonance and readout using Pauli spin blockade. In addition, we show individual coherent control of two qubits and measure single qubit fidelities of up to 99.3 per cent. We demonstrate the tunability of the exchange interaction between the two spins from 0.5 to 18 megahertz and use it to execute coherent two qubit controlled rotations. The demonstration of 'hot' and universal quantum logic in a semiconductor platform paves the way for quantum integrated circuits that host both the quantum hardware and its control circuitry on the same chip, providing a scalable approach towards practical quantum information processing. Lithographically defined qubits are shown to support full two qubit logic at temperatures above one kelvin by using electron spin states in silicon quantum dots.",
"author_names": [
"L Petit",
"H G J Eenink",
"Maximilian Russ",
"W I L Lawrie",
"Nico W Hendrickx",
"S G J Philips",
"James S Clarke",
"Lieven M K Vandersypen",
"Menno Veldhorst"
],
"corpus_id": 204401907,
"doc_id": "204401907",
"n_citations": 71,
"n_key_citations": 1,
"score": 0,
"title": "Universal quantum logic in hot silicon qubits",
"venue": "Nature",
"year": 2020
},
{
"abstract": "Individual impurity atoms in silicon can make superb individual qubits, but it remains an immense challenge to build a multi qubit processor: there is a basic conflict between nanometre separation desired for qubit qubit interactions and the much larger scales that would enable control and addressing in a manufacturable and fault tolerant architecture. Here we resolve this conflict by establishing the feasibility of surface code quantum computing using solid state spins, or 'data qubits' that are widely separated from one another. We use a second set of 'probe' spins that are mechanically separate from the data qubits and move in and out of their proximity. The spin dipole dipole interactions give rise to phase shifts; measuring a probe's total phase reveals the collective parity of the data qubits along the probe's path. Using a protocol that balances the systematic errors due to imperfect device fabrication, our detailed simulations show that substantial misalignments can be handled within fault tolerant operations. We conclude that this simple 'orbital probe' architecture overcomes many of the difficulties facing solid state quantum computing, while minimising the complexity and offering qubit densities that are several orders of magnitude greater than other systems. Scientists in the UK propose a solution for the miniaturization of quantum computers utilizing movable read out stages. A team led by Simon Benjamin of Oxford University and John Morton of University College London aimed to resolve the difficulty inherent in interacting with many qubits within a scalable quantum computer based on impurity atoms in silicon. The researchers propose a device architecture based on two moving silicon chips, where impurity atoms embedded in a movable silicon 'probe stage' hover above a silicon 'data stage' to control and access the qubits. The architecture arranges the impurities in a checkerboard pattern and is optimized for the 'surface code' a method of protecting qubits from errors in a device of any size. This represents a promising approach for developing scalable quantum computers.",
"author_names": [
"Joe O'Gorman",
"Naomi Nickerson",
"Philipp Ross",
"John J L Morton",
"Simon C Benjamin"
],
"corpus_id": 17365701,
"doc_id": "17365701",
"n_citations": 50,
"n_key_citations": 0,
"score": 0,
"title": "A silicon based surface code quantum computer",
"venue": "",
"year": 2014
},
{
"abstract": "Abstract. One way for solar cell efficiencies to overcome the Shockley Queisser limit is downconversion of high energy photons using singlet fission (SF) in polyacenes like tetracene (Tc) SF enables generation of multiple excitons from the high energy photons, which can be harvested in combination with Si. In this work, we investigate the use of lead sulfide quantum dots (PbS QDs) with a band gap close to Si as an interlayer that allows Forster resonant energy transfer (FRET) from Tc to Si, a process that would be spin forbidden without the intermediate QD step. We investigate how the conventional FRET model, most commonly applied to the description of molecular interactions, can be modified to describe the geometry of QDs between Tc and Si and how the distance between QD and Si, and the QD bandgap affects the FRET efficiency. By extending the acceptor dipole in the FRET model to a 2 D plane, and to the bulk, we see a relaxation of the distance dependence of transfer. Our results indicate that FRET efficiencies from PbS QDs to Si well above 50% are possible at very short but possibly realistic distances of around 1 nm, even for QDs with relatively low photoluminescence quantum yield.",
"author_names": [
"Stefan W Tabernig",
"Benjamin Daiber",
"T Wang",
"Bruno Ehrler"
],
"corpus_id": 55836589,
"doc_id": "55836589",
"n_citations": 10,
"n_key_citations": 0,
"score": 0,
"title": "Enhancing silicon solar cells with singlet fission: the case for Forster resonant energy transfer using a quantum dot intermediate",
"venue": "",
"year": 2018
},
{
"abstract": "One way to surpass the Shockley Queisser limit is the use of a downconversion mechanism to obtain two excitons from an initial excitation by a high energy photon. Singlet fission is such a downconversion process, enabling separation of a singlet state exciton into two triplet state excitons. Tetracene is a material that exhibits singlet fission and the energy of the triplet exciton (1.25 eV) lies above the bandgap of Si (1.12 eV) This means that if energy transfer from Tc to Si can be achieved, the high energy range of the solar spectrum can be harvested much more efficiently by adding a Tc layer on top of a Si solar cell. One way to achieve this energy transfer is by introducing PbS QDs as an intermediate. This geometry makes use of efficiently working Dexter energy transfer between Tc and PbS QDs. However, the mechanism for the subsequent transfer step from the PbS QDs to Si has not yet been identified. Here, we investigate Forster resonance energy transfer as a possible mechanism and use its theoretical framework to obtain a Forster model for our geometry. Furthermore, we compare this model with experiment by investigating the dependence of the QD PL lifetime on the QD Si separation. The results show that energy transfer with an efficiency of up to 15.3 is possible. However, the data does not allow to draw a final conclusion regarding the underlying transfer mechanism.",
"author_names": [
"E Burke"
],
"corpus_id": 208981254,
"doc_id": "208981254",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Forster resonance energy transfer from PbS quantum dots to silicon",
"venue": "",
"year": 2018
},
{
"abstract": "Silicon spin qubits have emerged as a promising path to large scale quantum processors. In this prospect, the development of scalable qubit readout schemes involving a minimal device overhead is a compelling step. Here we report the implementation of gate coupled rf reflectometry for the dispersive readout of a fully functional spin qubit device. We use a p type double gate transistor made using industry standard silicon technology. The first gate confines a hole quantum dot encoding the spin qubit, the second one a helper dot enabling readout. The qubit state is measured through the phase response of a lumped element resonator to spin selective interdot tunneling. The demonstrated qubit readout scheme requires no coupling to a Fermi reservoir, thereby offering a compact and potentially scalable solution whose operation may be extended above 1 K.Gate reflectometry is a recently demonstrated measurement technique for single spin states in silicon. It is potentially able to perform quantum non demolition measurements and uses compact circuitry that can be scaled up to larger quantum computers. Crippa et al. successfully combine gate reflectometry qubit readout and coherent control.",
"author_names": [
"Alessandro Crippa",
"R Ezzouch",
"Agostino Apra",
"A Amisse",
"R Lavieville",
"Louis Hutin",
"Benoit Bertrand",
"Maud Vinet",
"Matias Urdampilleta",
"Tristan Meunier",
"Marc Sanquer",
"Xavier Jehl",
"Romain Maurand",
"Silvano de Franceschi"
],
"corpus_id": 53679413,
"doc_id": "53679413",
"n_citations": 48,
"n_key_citations": 0,
"score": 0,
"title": "Gate reflectometry dispersive readout and coherent control of a spin qubit in silicon",
"venue": "Nature Communications",
"year": 2019
}
] |
Laser Processing and Chemistry | [
{
"abstract": "Part I Overview and Fundamentals: Introduction. Thermal, Photophysical, and Photochemical Processes. Reaction Kinetics and Transport of Species. Nucleation and Cluster Formation. Lasers, Experimental Aspects, Spatial Confinement. Part II Temperature Distributions and Surface Melting: General Solutions of the Heat Equations. Semi infinite Substrates. Infinite Slabs. Non uniform Media. Surface Melting. Part III Material Removal: Vaporization, Plasma Formation. Nanosecond Laser Ablation. Ultrashort Pulse Laser Ablation. Etching of Metals and Insulators. Etching of Semiconductors. Part IV Material Deposition: Laser CVD of Microstructures. Growth of Fibers. Direct Writing. Thin Film Formation by Laser CVD. Adsorbed Layers, Laser MBE. Liquid Phase Deposition, Electroplating. Thin Film Formation by Pulsed Laser Deposition and Laser Induced Evaporation. Part V Material Transformations, Synthesis and Structure Formation: Material Transformations, Laser Cleaning. Doping. Cladding, Alloying, and Synthesis. Oxidation, Nitridation, and Reduction. Transformation and Functionalization of Organic Materials. Instabilities and Structure Formation. Part VI Diagnostic Techniques, Plasmas: Diagnostic Techniques. Analysis of Species and Plasmas, Part VII Lasers in Medicine, Biotechnology and Arts: Lasers in Medicine and Biotechnology. Restoration and Conservation of Artworks.",
"author_names": [
"Dieter Bauerle"
],
"corpus_id": 94065618,
"doc_id": "94065618",
"n_citations": 2082,
"n_key_citations": 75,
"score": 1,
"title": "Laser Processing and Chemistry",
"venue": "",
"year": 1996
},
{
"abstract": "Laser induced material processing is reviewed with special emphasis on recent achievements mainly obtained by the Linz group. Among those are investigations using optical fiber tips for nanoscale photophysical etching, the pulsed laser deposition of thin films of high temperature superconductors (HTSs) and polytetrafluoroethylene (PTFE) and the laser cleaning of surfaces.",
"author_names": [
"Dieter Bauerle"
],
"corpus_id": 137182878,
"doc_id": "137182878",
"n_citations": 351,
"n_key_citations": 43,
"score": 0,
"title": "Laser processing and chemistry: recent developments",
"venue": "",
"year": 2002
},
{
"abstract": "Abstract.Laser induced material processing is reviewed with special emphasis on recent achievements mainly obtained by the Linz group. Among those are investigations using optical fiber tips for nanoscale photophysical etching, laser induced surface patterning using self assembled microspheres, the pulsed laser deposition of thin films of high temperature superconductors and the modification and cleaning of surfaces.",
"author_names": [
"Dieter Bauerle",
"Richard Denk",
"Johannes D Pedarnig",
"Klaus Piglmayer",
"Johannes Heitz",
"G Schrems"
],
"corpus_id": 97344862,
"doc_id": "97344862",
"n_citations": 14,
"n_key_citations": 0,
"score": 0,
"title": "Perspectives of laser processing and chemistry",
"venue": "",
"year": 2003
},
{
"abstract": "This overview reports recent experimental and theoretical investigations on laser processing. Among these are the submicron and nano patterning of surfaces by means of both nearfield optical techniques and microlens arrays formed by self organization processes; the pulsed laser deposition (PLD) of thin films including organic, inorganic and composite materials, and the modification of material surfaces. The latter field, and in particular the surface modification of polytetrafluoroethylene (PTFE, Teflon) has various different applications in biotechnology and medicine. Many of these results have been achieved during the long standing collaboration between the groups in Linz and Bucharest.",
"author_names": [
"Dieter Bauerle",
"Johannes D Pedarnig",
"Ionela Vrejoiu",
"Martin Dr Dipl -Ing Peruzzi",
"Dan G Matei",
"Daniel Brodoceanu",
"Maria Dinescu"
],
"corpus_id": 73572234,
"doc_id": "73572234",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "LASER PROCESSING AND CHEMISTRY: APPLICATIONS IN NANOPATTERNING, MATERIAL SYNTHESIS AND BIOTECHNOLOGY",
"venue": "",
"year": 2005
},
{
"abstract": "Das Buch ist in fiinf Kapitel eingeteilt, in denen die allgemeinen Laserprinzipien, die wichtigsten heute verfiigbaren Lasersysteme bis hin zum Titan Saphir Laser, die grundlegenden Laserverfahren und Techniken, die Laserspektroskopie und die laserinduzierte Chemie behandelt werden. Zu den einzelnen Kapiteln gibt es einige ausgewahlte Aufgaben mit Ergebnissen im Anhang. Der Anhang enthalt auBerdem die wichtigsten Laserwellenlangen, Akronyme, Abkurzungen und eine ausgewahlte Bibliographie. Die Auswahl des Stoffes ist ausgewogen und in der neuen Auflage der aktuellen Entwicklung angepaBt. Ein Vorteil des Buches ist die Beschrankung auf 232 Seiten, da ausfiihrlichere Darstellungen verschiedener Teilaspekte verfiigbar sind. Das Buch stellt eine Einfiihrung in die obigen Themengebiete dar. Die Darstellung des Stoffes ist sehr klar, einfach und gut verstandlich. Sorgfaltig ausgewahlte schematische Darstellungen und Bilder aus Publikationen mit neuesten Forschungsergebnissen illustrie",
"author_names": [
"Klaus Zimmer"
],
"corpus_id": 100775535,
"doc_id": "100775535",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Laser Processing and Chemistry",
"venue": "",
"year": 1999
},
{
"abstract": "Laser induced material processing is reviewed with special emphasis on recent achievements mainly obtained by the Linz group. Among those are investigations using optical fiber tips for nanoscale photophysical etching, laser induced ablation using self assembled microspheres, the pulse laser deposition of thin films of high temperature superconductors (HTS) and polytetrafluoroethylene (PTFE) and the modification and cleaning of surfaces.",
"author_names": [
"Dieter Prof Dr Baeuerle"
],
"corpus_id": 136128998,
"doc_id": "136128998",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Perspectives of laser processing and chemistry",
"venue": "SPIE High Power Laser Ablation",
"year": 2002
},
{
"abstract": "",
"author_names": [
"W Biegel"
],
"corpus_id": 93917989,
"doc_id": "93917989",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "D. Bliuerle Laser Processing and Chemistry. Second Edition, Springer Verlag, Berlin Heidelberg New York, 1996, ISBN: 3 540 60541 X, DM 128,00.",
"venue": "",
"year": 1997
},
{
"abstract": "Laser induced material processing is reviewed with special emphasis on recent achievements mainly obtained by the Linz group. Among those are investigations using optical fiber tips for nanoscale photophysical etching, laser induced surface patterning using self assembled microspheres, the pulsed laser deposition of thin films of high temperature superconductors and the modification and cleaning of surfaces.",
"author_names": [
"Angewandte Physik"
],
"corpus_id": 138675477,
"doc_id": "138675477",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Perspectives of laser processing and chemistry",
"venue": "",
"year": 2003
},
{
"abstract": "Abstract A lot of research efforts have been invested in the fabrication of superhydrophobic surfaces in recent years due to many protentional applications in science and industry including anti icing, self cleaning and anti corrosive surfaces. Laser as a non polluting, precise and flexible tool can be applied to replicate surface microstructures of extremely water repellent lotus leave surface. In this study, a common nanosecond laser source is used to fabricate a super/ultrahydrophobic surfaces with different microstructure designs, contact angles above 170deg and sliding angles below 5deg. The freshly processed surface is hydrophilic and becomes hydrophobic and superhydrophobic in a certain time period, which could be dramatically reduced by storing samples in high vacuum. The transformation in wetting properties are analysed with respect to surface geometry and surface chemistry.",
"author_names": [
"Petr Hauschwitz",
"R Jagdheesh",
"D Rostohar",
"Jan Brajer",
"J Kopecek",
"Petr Jiricek",
"Jana Houdkova",
"T Mocek"
],
"corpus_id": 210240787,
"doc_id": "210240787",
"n_citations": 14,
"n_key_citations": 0,
"score": 0,
"title": "Hydrophilic to ultrahydrophobic transition of Al 7075 by affordable ns fiber laser and vacuum processing",
"venue": "",
"year": 2020
},
{
"abstract": "Abstract Wettability plays a major role in a variety of surface related phenomena, as corrosion, heat transfer or tissue adhesion on implants. Consequently, great research effort is being devoted to control the wetting degree of functional surfaces. Pulsed laser texturing at micro/nanometric level has been widely used for that purpose as a precision/time efficient technique. This work studies the role of the processing atmosphere in controlling the wettability of commercial AISI 304 by laser texturing. A pulsed laser source (l 532 nm) working at the nanosecond regime was employed and five different atmospheres were tested (i.e. O2, Air, CO2, N2, Ar) The results show clear differences in the wetting behaviour depending solely on the processing environment, ranging from hydrophilicity (31deg) to hydrophobicity (125deg) Those differences in wettability were found to be a consequence of changes in surface chemistry between samples processed under the various gases. The laser processing parameters showed a capability to tune the final wetting behaviour by controlling the topography and modulating the chemical composition given by the processing environment. It is demonstrated how the effects of the atmosphere can be exploited to tailor the wettability of the untreated surfaces (th 88deg) up to the desired value, ranging from superhydrophilicity (th 0deg) to superhydrophobicity (th 152deg)",
"author_names": [
"Pablo Pou",
"Jesus del Val",
"Antonio Riveiro",
"Rafael Comesana",
"Felipe Arias-Gonzalez",
"F Lusquinos",
"M Bountinguiza",
"Felix Quintero",
"Juan Pou"
],
"corpus_id": 139379593,
"doc_id": "139379593",
"n_citations": 30,
"n_key_citations": 1,
"score": 0,
"title": "Laser texturing of stainless steel under different processing atmospheres: From superhydrophilic to superhydrophobic surfaces",
"venue": "Applied Surface Science",
"year": 2019
}
] |
Solid state industrial relays | [
{
"abstract": "This paper focuses on providing an improved and efficient alternative to electromechanical relays (EMRs) in view of the growing demand characteristics for an effective power multiplexing in induction heating applications. A major analytical approach to the design and implementation of bidirectional switches (BDSs) based on different power semiconductor technologies is presented, including thorough static and dynamic characterizations. Emerging gallium nitride high electron mobility transistors (GaN HEMTs) and silicon carbide (SiC) based devices are identified as potential candidates for the mentioned applications.",
"author_names": [
"Manuel Fernandez",
"Xavier Perpina",
"Jose Rebollo",
"Miquel Vellvehi",
"David Sanchez",
"Tomas Cabeza",
"Sergio Llorente",
"Xavier Jorda"
],
"corpus_id": 53239423,
"doc_id": "53239423",
"n_citations": 8,
"n_key_citations": 0,
"score": 1,
"title": "Solid State Relay Solutions for Induction Cooking Applications Based on Advanced Power Semiconductor Devices",
"venue": "IEEE Transactions on Industrial Electronics",
"year": 2019
},
{
"abstract": "In this paper, an electromagnetic compatibility estimator is proposed using an artificial neural network with a scaled conjugate gradient algorithm. Neural networks are trained with the help of seven different optimization algorithms in MATLAB. Their performance is evaluated on the basis of number of neurons, desired output, and mean squared error in offline mode in MATLAB. Among seven algorithms, scaled conjugate gradient algorithm is found to be the best choice. Hence, it is implemented in LabVIEW for online assessment of electromagnetic compatibility issues. Voltage dip, swell, and harmonics are generated with the help of an experimental setup. It consists of 230 V, 50 Hz input voltage supply, microcontroller, variac, and solid state relays. It is interfaced to the LabVIEW software with the help of an NI USB 6361 data acquisition system. It enabled the continuous online monitoring of various signals. Along with voltage dip and swell, harmonics are also evaluated with the help of spectrum analyzer in LabVIEW. The detailed description of a hardware setup and mathematical modeling of trained network is given in this paper.",
"author_names": [
"Chetan B Khadse",
"Madhuri A Chaudhari",
"Vijay B Borghate"
],
"corpus_id": 26463949,
"doc_id": "26463949",
"n_citations": 24,
"n_key_citations": 0,
"score": 0,
"title": "Electromagnetic Compatibility Estimator Using Scaled Conjugate Gradient Backpropagation Based Artificial Neural Network",
"venue": "IEEE Transactions on Industrial Informatics",
"year": 2017
},
{
"abstract": "In today's portable devices, major DC DC topologies are mixed and matched to provide multiple DC rails to power point of load (POL) rails. The traditional high frequency DC converter approaches to achieve high efficiency have their strengths and draw backs, and none of them could be considered ideal solution to energy efficiency and battery run time issues of modern portable devices. Supercapacitor assisted low dropout regulators (SCALDO) is a novel linear regulator topology developed by combining an array of supercapacitors, an LDO and a very low frequency switching arrangement to achieve high efficiency in linear converter comparable with high frequency switching converters. The technique implemented in commonly used DC DC converter stages such as 12 5V, 5 3.3 V and 5 1.2 V with efficiency improvement factors of 2, 1.33 and 3 respectively, with the example of increasing the 42% efficiency of a 12 5 V linear converter to 84% theoretically. In these early prototype versions, solid state relays were used as the low frequency switches to eliminate the unnecessary discharging of the supercapacitors (SC) however, high on resistance in these switches increase the switch losses. This paper provides the details of a new design technique to eliminate this SC discharge issue and to further reduce the switch losses by using back to back MOSFET switches, together with performance details of 12 5 V practical converter.",
"author_names": [
"Kosala Gunawardane",
"Sting Xie",
"Nihal Kularatna"
],
"corpus_id": 22806422,
"doc_id": "22806422",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Back to back MOSFET switches to reduce the losses in SCALDO implementation",
"venue": "2017 IEEE International Conference on Industrial Technology (ICIT)",
"year": 2017
},
{
"abstract": "Ground differential protection relays (device 87G) have been used to protect the windings of resistance grounded power transformers. There have been problems of relay misoperation and nonoperation with electromechanical 87G relays due to current transformer (CT) burden and saturation. Due to their low burden, it has been assumed by some that solid state digital relays are not subject to these problems. The purpose of this paper is to evaluate the truth of this assumption. Under what circumstances, and with what types of CTs, might problems occur? An analysis is performed of digital ground differential protection over a range of power transformer and CT sizes. Guidelines are developed for CT accuracy ratings suitable for this application. The effect of different relay algorithms on scheme performance relative to CTs is also discussed.",
"author_names": [
"Peter E Sutherland"
],
"corpus_id": 108495688,
"doc_id": "108495688",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Current transformer application with digital ground differential protection relays",
"venue": "2000 IEEE Industrial and Commercial Power Systems Technical Conference. Conference Record (Cat. No.00CH37053)",
"year": 2000
},
{
"abstract": "A variety of electromechanical and solid state protective relays were tested for pickup and time delay characteristics while tilted in several directions from vertical and while undergoing oscillatory motion. These tests showed that induction disk and induction cup relays were seriously affected by tilting and motion, but that hinged armature and solid state relays were not affected.<ETX>",
"author_names": [
"Baldwin Bridger",
"Robert J Walker"
],
"corpus_id": 110302080,
"doc_id": "110302080",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Operating characteristics of protective relays in positions other than vertical",
"venue": "Conference Record, Industrial and Commercial Power Systems Technical Conference, 1988.",
"year": 1988
},
{
"abstract": "Electromechanical relays were the first logic element used in a computer. Today, small compact reed relays are again being extensively used as logic elements. A logic factor, FL, measures the improvement that a logic device can affect if interposed between a logic source and logic detector. A logic figure of merit, TFM, determined when FL 1.0 can be used for comparison of the logic performance of logic devices. TFM is developed for an arbitrary electromechanical relay. For a miniature reed relay packaged for printed circuit boards, TFM 1.7 milliseconds. For comparison, solid state devices have TFM 1 nanoseconds and COSMOS (complementary symmetry metal oxide semiconductor) devices have TFM 20 nanoseconds.",
"author_names": [
"Lawrence Joseph Giacoletto"
],
"corpus_id": 9731398,
"doc_id": "9731398",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Logic Rating of Electromechanical Relays",
"venue": "IEEE Transactions on Industrial Electronics and Control Instrumentation",
"year": 1975
},
{
"abstract": "There are many advantages to upgrading old electromechanical, solid state, and first generation numeric relays with modern numeric relays. Reliability increases because there is less direct wiring and interconnection wiring. Reliability and security of multifunction logic and settings are improved with next generation user interface software. Remote I/O modules, remote analog/digital inputs, and thermal measurement capabilities have expanded the protection, control, and monitoring. New protection and monitoring features improve power system equipment life and increase personnel safety. Maintenance costs are reduced, while internal watchdogs alert the user if the relay has a problem. Settings groups can be changed instantaneously to adapt to varying power system requirements. Modern, second generation numeric relays offer a variety of secure communications capabilities for interfacing with Smart Grid controls, SCADA systems, and business networks. Event memory is larger for more on board, standardized oscillographs and event reporting. Relay security is in accord with the latest NERC standards. Initially, every relay upgrade seems simple and straight forward; then come the details. Operating personnel have expectations for reading targets, resetting trips, ease of interface for settings and events, motor restarting, synch closing, etc. Regulator requirements (NERC CIP, for example) must be implemented while maintaining smooth operations. Relay engineers must assure that operational ease is maintained with the new upgrade relay. Accurate one line drawings and connection drawings, as well as good wiring documentation, are essential. Escutcheon plates might be necessary, or perhaps switchgear will need modification (panel cutting, new doors, relocation, etc) Also, this is an opportunity to reevaluate arc flash hazards and possibly reduce the risks. These and other considerations are taken from actual relay replacement projects. This paper provides guidance for your next replacement or upgrade project, resulting in reducing cost, saving time, and minimizing unexpected or unplanned complications.",
"author_names": [
"Daniel L Ransom"
],
"corpus_id": 47569917,
"doc_id": "47569917",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Upgrading relay protection? Be prepared",
"venue": "49th IEEE/IAS Industrial Commercial Power Systems Technical Conference",
"year": 2013
},
{
"abstract": "Electrical engineering students at the University of South Australia have worked on an energy efficient 10 kVA 3 phase switchable distribution transformer system as their final year project in their undergraduate degree. Past research has shown that transformer efficiency gains can be made by switching between series and parallel winding configurations. A dsPIC33FJ256GP710 microcontroller is utilized to acquire transformer performance data from voltage and current sensors and perform waveform analysis (RMS magnitude and phase) using DSP techniques. In addition the microcontroller coordinates the switching of the winding configurations using solid state relays to obtain the optimum efficiency of the transformation of electrical power.",
"author_names": [
"Sam A M Ali",
"K McGlasson",
"Paul Waterloo Drennan",
"J How"
],
"corpus_id": 16285830,
"doc_id": "16285830",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Development of a data acquisition and analysis system for a 10 kVA 3 phase switchable distribution transformer",
"venue": "2008 3rd IEEE Conference on Industrial Electronics and Applications",
"year": 2008
},
{
"abstract": "The electromagnetic, electromechanical and solid state (analog electronic) technologies have been used in protection systems since the late 1800's. The developments in VLSI circuits prompted the use of analog electronics in designing and building protective relays. Since the introduction of microprocessors, their use in protection systems has been increasing gradually. The modern protection systems use them along with the needed analog electronics. The technologies used in protection systems are described in this paper. Some of the changes in the designs that have become possible due to the versatility of the present technologies are discussed. Some thoughts on the expected direction in which power system protection is likely to move are identified.",
"author_names": [
"M S Sachdev"
],
"corpus_id": 19079929,
"doc_id": "19079929",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Technologies used in Power System Protection Systems",
"venue": "2006 IEEE International Conference on Industrial Technology",
"year": 2006
},
{
"abstract": "The application of microcomputer based relays grow rapidly and a number of microprocessor based protective relays are applied in electric utility power systems. Since the performances of the protective relays are normally categorized by their function, the same test procedure is applied to a group of relays with the same protective function regardless of their operation mechanism. Unlike electromechanical or solid state relays, a microcomputer based relay is a software driven system. The performance of such a relay depends on the hardware design, the accuracy of the input signals and the algorithms embedded inside the unit. Though they may have similar protective functions, the physical capability and constraints of microcomputer based relays may vary from one vendor to another. Some of these features are difficult to be tested or evaluated through traditional testing procedures. This paper discusses the hardware and software design issues and illustrates how they can affect the performance of a microcomputer based relay system.",
"author_names": [
"Weijen Lee"
],
"corpus_id": 110121016,
"doc_id": "110121016",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Beyond the normal testing procedure a closer look at the microcomputer based relay",
"venue": "1997 IEEE Industrial and Commercial Power Systems Technical Conference. Conference Record",
"year": 1997
}
] |
quantum light source waveguide | [
{
"abstract": "Ultrafast electro optical conversion at nanoscale is of fundamental interest for information transfer and optical interconnects. Light emission from a quantum tunnel junction provides an opportunity owing to its unique capability of ultrafast response and small footprint. However, the main challenge to the wide adoption of the tunnel junction is its low emission efficiency caused by the low inelastic electron tunneling proportion and radiation efficiency. In this Letter, an electrically driven silicon light source with its efficiency enhanced by using a nano antenna in a metal insulator semiconductor junction is proposed. Strong plasmon confinement in the nano antenna provides large local density of optical states and bridges the wave vector mismatch between nanoscale volume field confinement and far field radiation. Two orders of magnitude of emission enhancement are achieved over typical planar MIS junctions.",
"author_names": [
"Bao-Hu Huang",
"Si-Ping Gao",
"Yan Liu",
"Jian Wang",
"Zhenguo Liu",
"Yong-xin Guo",
"Weibing Lu"
],
"corpus_id": 141510462,
"doc_id": "141510462",
"n_citations": 4,
"n_key_citations": 0,
"score": 1,
"title": "Nano antenna enhanced waveguide integrated light source based on an MIS tunnel junction.",
"venue": "Optics letters",
"year": 2019
},
{
"abstract": "Industrial and environmental sensing applications require compact, robust and cost effective mid IR light sources for multiline spectroscopy. An essential feature of such source is the ability to generate multiple emission lines on demand, i.e. in a programmable fashion. Building blocks for an integrated programmable light sources operating 2 to 3 mm wavelength band are presented. Our approach is based on mm scale Silicon on Insulator technology and GaSb based quantum well broadband emitter demonstrates. In particular, we focus on presenting state of the art developments of amplified spontaneous emission sources emitting within 2 mm to 2.65 mm quantum wells and present their application as semiconductor optical amplifiers. Progress towards emission at 3 mm using GaInAsSb/AlGa(In)AsSb quantum wells in single transvers mode superluminescent LEDs is also discussed. Moreover, performance merits for various circuit elements prepared using micron scale Silicon oninsulator technology are described; these include waveguides with low propagation and bend losses and echelle gratings for wavelength selection.",
"author_names": [
"Jukka Viheriala",
"Matteo Cherchi",
"Heidi Tuorila",
"Nouman Zia",
"Eero S Koivusalo",
"Samu-Pekka Ojanen",
"P Karioja",
"Mircea D Guina"
],
"corpus_id": 220702058,
"doc_id": "220702058",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Building blocks for mid IR programmable light source based on GaSb based amplified spontaneous emission sources and mm scale Silicon on Insulator waveguide photonics",
"venue": "",
"year": 2019
},
{
"abstract": "We herein propose and verify an ultra small near infrared (NIR) multi wavelength light source using a heterojunction photonic crystal waveguide (PC WG) and quantum dots (QDs) A heterojunction two dimensional PC WG, which consists of multiple PC WGs with sequentially shifted structural parameters, is fabricated on a GaAs slab including InAs QDs. Spontaneous emission (SE) from embedded InAs QDs was enhanced at multiple wavelengths resonating with slow light regions of the PC WG modes. The enhanced SE was propagated and detected through the heterojunction PC WG. These results indicate the feasibility of the proposed light source.",
"author_names": [
"Sho Uchida",
"Nobuhiko Ozaki",
"Teruyuki Nakahama",
"Hisaya Oda",
"Naoki Ikeda",
"Yoshimasa Sugimoto"
],
"corpus_id": 125327279,
"doc_id": "125327279",
"n_citations": 6,
"n_key_citations": 0,
"score": 0,
"title": "Ultra small near infrared multi wavelength light source using a heterojunction photonic crystal waveguide and self assembled InAs quantum dots",
"venue": "",
"year": 2017
},
{
"abstract": "",
"author_names": [
"Ryota Katsumi",
"Yasutomo Ota",
"Satoshi Iwamoto",
"Hidefumi Akiyama",
"Yasuhiko Arakawa"
],
"corpus_id": 219868771,
"doc_id": "219868771",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Design of a quantum dot single photon source integrated on a Si waveguide for realizing unidirectional light output",
"venue": "",
"year": 2019
},
{
"abstract": "",
"author_names": [
"Uchida Sho",
"Ozaki Nobuhiko",
"Oda Hisaya",
"Ikeda Naoki",
"Sugimoto Yoshimasa"
],
"corpus_id": 136286414,
"doc_id": "136286414",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Multi wavelength near infrared light source using heterojunction 2D GaAs photonic crystal waveguide with InAs quantum dots",
"venue": "",
"year": 2017
},
{
"abstract": "We report a valley photonic crystal (VPhC) waveguide in a GaAs slab with InAs quantum dots (QDs) as an internal light source exploited for experimental characterization of the waveguide. A topological interface state formed at the interface between two topologically distinct VPhCs is used as the waveguide mode. We demonstrate robust propagation for near infrared light emitted from the QDs even under the presence of sharp bends as a consequence of the topological protection of the guided mode. Our work will be of importance for developing robust photonic integrated circuits with small footprints, as well as for exploring active semiconductor topological photonics.",
"author_names": [
"Takuto Yamaguchi",
"Yasutomo Ota",
"Ryota Katsumi",
"Katsuyuki Watanabe",
"Satomi Ishida",
"Alto Osada",
"Yasuhiko Arakawa",
"Satoshi Iwamoto Institute of Industrial Science",
"The University of Tokyo",
"Institute of Quantum Electronics"
],
"corpus_id": 102350678,
"doc_id": "102350678",
"n_citations": 14,
"n_key_citations": 0,
"score": 0,
"title": "GaAs valley photonic crystal waveguide with light emitting InAs quantum dots",
"venue": "Applied Physics Express",
"year": 2019
},
{
"abstract": "Photonic quantum technologies allow quantum phenomena to be exploited in applications such as quantum cryptography, quantum simulation and quantum computation. A key requirement for practical devices is the scalable integration of single photon sources, detectors and linear optical elements on a common platform. Nanophotonic circuits enable the realization of complex linear optical systems, while non classical light can be measured with waveguide integrated detectors. However, reproducible single photon sources with high brightness and compatibility with photonic devices remain elusive for fully integrated systems. Here, we report the observation of antibunching in the light emitted from an electrically driven carbon nanotube embedded within a photonic quantum circuit. Non classical light generated on chip is recorded under cryogenic conditions with waveguide integrated superconducting single photon detectors, without requiring optical filtering. Because exclusively scalable fabrication and deposition methods are used, our results establish carbon nanotubes as promising nanoscale single photon emitters for hybrid quantum photonic devices. Single photons are generated from electrically driven semiconducting single walled carbon nanotubes embedded in a photonic circuit. Pronounced antibunching is observed when photon correlation is measured at cryogenic temperatures.",
"author_names": [
"Svetlana Khasminskaya",
"F Pyatkov",
"Karolina Slowik",
"Simone Ferrari",
"Oliver Kahl",
"Vadim Kovalyuk",
"Patrik Rath",
"Andreas Vetter",
"Frank Dr Hennrich",
"Manfred M Kappes",
"Gregory N Goltsman",
"Alexander Korneev",
"Carsten Rockstuhl",
"Ralph Krupke",
"Wolfram H P Pernice"
],
"corpus_id": 125293218,
"doc_id": "125293218",
"n_citations": 148,
"n_key_citations": 4,
"score": 0,
"title": "Fully integrated quantum photonic circuit with an electrically driven light source",
"venue": "",
"year": 2016
},
{
"abstract": "",
"author_names": [
"Hisaya Oda",
"Akio Yamanaka",
"Sho Uchida",
"Nobuhiko Ozaki",
"Naoki Ikeda",
"Yoshimasa Sugimoto"
],
"corpus_id": 138684295,
"doc_id": "138684295",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Photoluminescence characteristics of multi wavelength near infrared light source using a heterojunction photonic crystal waveguide including quantum dots",
"venue": "",
"year": 2016
},
{
"abstract": "Chip scale frequency combs such as those based on quantum cascade lasers (QCLs) or microresonators are attracting tremendous attention because of their potential to solve key challenges in sensing and metrology. Though nonlinearity and proper dispersion engineering can create a comb light whose lines are perfectly evenly spaced these devices can enter into different states depending on their history, a critical problem that can necessitate slow and manual intervention. Moreover, their large repetition rates are problematic for applications such as dual comb molecular spectroscopy, requiring gapless tuning of the offset. Here, we show that by blending midinfrared QCL combs with microelectromechanical comb drives, one can directly manipulate the dynamics of the comb and identify new physical effects. Not only do the resulting devices remain on a chip scale and are able to stably tune over large frequency ranges, but they can also switch between different comb states at extremely high speeds. We use these devices to probe hysteresis in comb formation and develop a protocol for achieving a particular comb state regardless of its initial state. Published under license by AIP Publishing. https:/doi.org/10.1063/1.5098086 Chip scale frequency combs are expected to have an enormous impact in the area of sensing, as their properties give them unique abilities in spectroscopy and ranging. In particular, quantum cascade laser (QCL) combs operating in the midinfrared and terahertz regions offer the ability to perform sensing in the highly relevant \"molecular fingerprint\" ranges, where many molecules relative to chemical and biological sensing have fundamental rovibrational transitions. Nonetheless, one challenge associated with these devices is that even with proper dispersion engineering, the spatial hole burning (SHB) mechanism that enables comb formation sometimes allows for multiple types of comb states to form. Although the combs are extremely \"reproducible\" turning the comb on the same way always leads it to a definite state under usage conditions, they are frequently \"multistable,\" entering into different states based on their history. For example, one may access a particular state if the laser is simply turned on, but a different one by ramping the current up and back down. One could also destroy the comb state with optical feedback. A variety of states arise from the fact that the internal dynamics of QCLs attempt to maximize the average round trip gain of the laser by making use of SHB, which allows more than one mode to lase. However, even in the absence of dispersion, the energy landscape of SHB is highly nonmonotonic, possessing a small number of local maxima with similar round trip gains. These are locally stable, allowing them to be used in applications like dual comb spectroscopy, but perturbations can still cause them to jump between regimes. Unfortunately, accessing and controlling these states are difficult using conventional tuning schemes, such as changing the gain medium's bias and temperature. One way to modify the properties of a QCL comb without contact is to put an object near the facet, changing the intracavity dispersion. In principle, it also changes the mode profile and the SHB pattern of the cavity allowing different states to be accessed although it does so relatively slowly and at the cost of making the device no longer on a chip scale. In order to access these states, here we quasi integrate a microelectromechanical (MEMS) comb drive alongside a QCL frequency comb. The resulting device is still on the chip scale, but by blending it with a mirror whose position can be quickly modulated electrically, we can repeatably probe and access different comb states. In addition, Appl. Phys. Lett. 115, 021105 (2019) doi: 10.1063/1.5098086 115, 021105 1 Published under license by AIP Publishing Applied Physics Letters ARTICLE scitation.org/journal/apl",
"author_names": [
"David Patrick Burghoff",
"Ningren Han",
"Filippos Kapsalidis",
"Nathan Henry",
"Mattias Beck",
"Jacob B Khurgin",
"Jerome Faist",
"Q Y Hu"
],
"corpus_id": 198922310,
"doc_id": "198922310",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Efficient demultiplexed single photon source with a quantum dot coupled to a nanophotonic waveguide",
"venue": "",
"year": 2019
},
{
"abstract": "We report a broadband gain superluminescent diode (SLD) based on self assembled InAsquantum dots(QDs) for application in a high resolution optical coherence tomography(OCT) light source. Four InAsQD layers, with sequentially shifted emission wavelengths achieved by varying the thickness of the In0.2Ga0.8As strain reducing capping layers, were embedded in a conventional p n heterojunction comprising GaAs and AlGaAs layers. A ridge type waveguide with segmented contacts was formed on the grown wafer, and an as cleaved 4 mm long chip (QD SLD) was prepared. The segmented contacts were effective in applying a high injection current density to the QDs and obtaining emission from excited states of the QDs, resulting in an extension of the bandwidth of the electroluminescence spectrum. In addition, gain spectra deduced with the segmented contacts indicated a broadband smooth positive gain region spanning 160 nm. Furthermore, OCTimaging with the fabricated QD SLD was performed, and OCTimages with an axial resolution of ~4 mm in air were obtained. These results demonstrate the effectiveness of the QD SLD with segmented contacts as a high resolution OCT light source.",
"author_names": [
"Nobuhiko Ozaki",
"D T D Childs",
"Jayanta Sarma",
"Timothy S Roberts",
"Takuma Yasuda",
"Hiroshi Shibata",
"Hirotaka Ohsato",
"Eiichiro Watanabe",
"Naoki Ikeda",
"Yoshimasa Sugimoto",
"Richard A Hogg"
],
"corpus_id": 14623848,
"doc_id": "14623848",
"n_citations": 18,
"n_key_citations": 0,
"score": 0,
"title": "Superluminescent diode with a broadband gain based on self assembled InAs quantum dots and segmented contacts for an optical coherence tomography light source",
"venue": "",
"year": 2016
}
] |
A survey of routing algorithm for mesh Network-on-Chip | [
{
"abstract": "With the rapid development of semiconductor industry, the number of cores integrated on chip increases quickly, which brings tough challenges such as bandwidth, scalability and power into on chip interconnection. Under such background, Network on Chip (NoC) is proposed and gradually replacing the traditional on chip interconnections such as sharing bus and crossbar. For the convenience of physical layout, mesh is the most used topology in NoC design. Routing algorithm, which decides the paths of packets, has significant impact on the latency and throughput of network. Thus routing algorithm plays a vital role in a wellperformed network. This study mainly focuses on the routing algorithms of mesh NoC. By whether taking network information into consideration in routing decision, routing algorithms of NoC can be roughly classified into oblivious routing and adaptive routing. Oblivious routing costs less without adaptiveness while adaptive routing is on the contrary. To combine the advantages of oblivious and adaptive routing algorithm, half adaptive algorithms were proposed. In this paper, the concepts, taxonomy and features of routing algorithms of NoC are introduced. Then the importance of routing algorithms in mesh NoC is highlighted, and representative routing algorithms with respective features are reviewed and summarized. Finally, we try to shed light upon the future work of NoC routing algorithms.",
"author_names": [
"Yue Wu",
"Chao-bo Lu",
"Yunji Chen"
],
"corpus_id": 3431315,
"doc_id": "3431315",
"n_citations": 11,
"n_key_citations": 0,
"score": 2,
"title": "A survey of routing algorithm for mesh Network on Chip",
"venue": "Frontiers of Computer Science",
"year": 2016
},
{
"abstract": "In this paper we present a reconfigurable routing algorithm for a 2D mesh network on chip (NoC) dedicated to fault tolerant, massively parallel multi processors systems on chip (MP2 SoC) The routing algorithm can be dynamically reconfigured, to adapt to the modification of the micro network topology caused by a faulty router. This algorithm has been implemented in a reconfigurable version of the DSPIN micro network, and evaluated from the point of view of performance (penalty on the network saturation threshold) and cost (extra silicon area occupied by the reconfigurable version of the router)",
"author_names": [
"Zhen Zhang",
"Alain Greiner",
"Sami Taktak"
],
"corpus_id": 11991854,
"doc_id": "11991854",
"n_citations": 237,
"n_key_citations": 27,
"score": 0,
"title": "A reconfigurable routing algorithm for a fault tolerant 2D Mesh Network on Chip",
"venue": "2008 45th ACM/IEEE Design Automation Conference",
"year": 2008
},
{
"abstract": "1 Introduction 32 Routing on NoC 52.1 Network Topologies 52.2 Problems on Routing 72.2.1 Deadlock. 82.2.2 Livelock. 82.2.3 Starvation. 92.3 Network Flow Control 93 Oblivious Routing Algorithms 103.1 Dimension Order Routing 103.1.1 XY routing 103.2 Turn Models 113.3 Deterministic Routing Algorithms 123.3.1 Shortest Path Routing 133.3.2 Source Routing 133.3.3 Destination tag Routing 143.3.4 Topology Adaptive Routing 143.4 Stochastic Routing Algorithms 143.4.1 Flooding Algorithms 143.5 Summary 164 Adaptive Routing Algorithms 174.1 Minimal Adaptive Routing 174.2 Fully Adaptive Routing 174.2.1 Congestion Look Ahead 174.3 Turnaround Routing 174.4 Other Adaptive Routing Algorithms 184.5 Summary 205 Router Architectures 215.1 Oblivious Routers 215.1.1 Virtual Channel Router 215.1.2 Xpipes 225.1.3 AEthereal 235.1.4 Proteo 245.1.5 MANGO 255.1.6 SoCBUS 255.1.7 Arteris 265.1.8 STNoC 265.2 Adaptive Routers 261",
"author_names": [
"Ville Rantala",
"Teijo Lehtonen",
"Juha Plosila"
],
"corpus_id": 59762212,
"doc_id": "59762212",
"n_citations": 127,
"n_key_citations": 10,
"score": 0,
"title": "Network on Chip Routing Algorithms",
"venue": "",
"year": 2006
},
{
"abstract": "The scaling of microchip technologies has enabled large scale systems on chip (SoC) Network on chip (NoC) research addresses global communication in SoC, involving (i) a move from computation centric to communication centric design and (ii) the implementation of scalable communication structures. This survey presents a perspective on existing NoC research. We define the following abstractions: system, network adapter, network, and link to explain and structure the fundamental concepts. First, research relating to the actual network design is reviewed. Then system level design and modeling are discussed. We also evaluate performance analysis techniques. The research shows that NoC constitutes a unification of current trends of intrachip communication rather than an explicit new alternative.",
"author_names": [
"Tobias Bjerregaard",
"Shankar Mahadevan"
],
"corpus_id": 9938173,
"doc_id": "9938173",
"n_citations": 1685,
"n_key_citations": 66,
"score": 0,
"title": "A survey of research and practices of Network on chip",
"venue": "CSUR",
"year": 2006
},
{
"abstract": "Wireless mesh networks (WMNs) consist of mesh routers and mesh clients, where mesh routers have minimal mobility and form the backbone of WMNs. They provide network access for both mesh and conventional clients. The integration of WMNs with other networks such as the Internet, cellular, IEEE 802.11, IEEE 802.15, IEEE 802.16, sensor networks, etc. can be accomplished through the gateway and bridging functions in the mesh routers. Mesh clients can be either stationary or mobile, and can form a client mesh network among themselves and with mesh routers. WMNs are anticipated to resolve the limitations and to significantly improve the performance of ad hoc networks, wireless local area networks (WLANs) wireless personal area networks (WPANs) and wireless metropolitan area networks (WMANs) They are undergoing rapid progress and inspiring numerous deployments. WMNs will deliver wireless services for a large variety of applications in personal, local, campus, and metropolitan areas. Despite recent advances in wireless mesh networking, many research challenges remain in all protocol layers. This paper presents a detailed study on recent advances and open research issues in WMNs. System architectures and applications of WMNs are described, followed by discussing the critical factors influencing protocol design. Theoretical network capacity and the state of the art protocols for WMNs are explored with an objective to point out a number of open research issues. Finally, testbeds, industrial practice, and current standard activities related to WMNs are highlighted.",
"author_names": [
"Ian F Akyildiz",
"Xudong Wang",
"Weilin Wang"
],
"corpus_id": 9485158,
"doc_id": "9485158",
"n_citations": 4384,
"n_key_citations": 316,
"score": 0,
"title": "Wireless mesh networks: a survey",
"venue": "Comput. Networks",
"year": 2005
},
{
"abstract": "Recent advances in wireless sensor networks have led to many new protocols specifically designed for sensor networks where energy awareness is an essential consideration. Most of the attention, however, has been given to the routing protocols since they might differ depending on the application and network architecture. This paper surveys recent routing protocols for sensor networks and presents a classification for the various approaches pursued. The three main categories explored in this paper are data centric, hierarchical and location based. Each routing protocol is described and discussed under the appropriate category. Moreover, protocols using contemporary methodologies such as network flow and quality of service modeling are also discussed. The paper concludes with open research issues. 2003 Elsevier B.V. All rights reserved.",
"author_names": [
"Kemal Akkaya",
"Mohamed F Younis"
],
"corpus_id": 205286988,
"doc_id": "205286988",
"n_citations": 2791,
"n_key_citations": 152,
"score": 0,
"title": "A survey on routing protocols for wireless sensor networks",
"venue": "Ad Hoc Networks",
"year": 2005
},
{
"abstract": "Wireless mesh networks (WMNs) have emerged as a key technology for next generation wireless networking. Because of their advantages over other wireless networks, WMNs are undergoing rapid progress and inspiring numerous applications. However, many technical issues still exist in this field. In order to provide a better understanding of the research challenges of WMNs, this article presents a detailed investigation of current state of the art protocols and algorithms for WMNs. Open research issues in all protocol layers are also discussed, with an objective to spark new research interests in this field.",
"author_names": [
"Ian F Akyildiz",
"Xudong Wang"
],
"corpus_id": 815769,
"doc_id": "815769",
"n_citations": 1852,
"n_key_citations": 129,
"score": 0,
"title": "A survey on wireless mesh networks",
"venue": "IEEE Communications Magazine",
"year": 2005
},
{
"abstract": "Vehicular ad hoc network (VANET) is an emerging new technology integrating ad hoc network, wireless LAN (WLAN) and cellular technology to achieve intelligent inter vehicle communications and improve road traffic safety and efficiency. VANETs are distinguished from other kinds of ad hoc networks by their hybrid network architectures, node movement characteristics, and new application scenarios. Therefore, VANETs pose many unique networking research challenges, and the design of an efficient routing protocol for VANETs is very crucial. In this article, we discuss the research challenge of routing in VANETs and survey recent routing protocols and related mobility models for VANETs.",
"author_names": [
"Fan Li",
"Yu Wang"
],
"corpus_id": 15960295,
"doc_id": "15960295",
"n_citations": 1157,
"n_key_citations": 70,
"score": 0,
"title": "Routing in vehicular ad hoc networks: A survey",
"venue": "IEEE Vehicular Technology Magazine",
"year": 2007
},
{
"abstract": "Wireless sensor networks consist of small nodes with sensing, computation, and wireless communications capabilities. Many routing, power management, and data dissemination protocols have been specifically designed for WSNs where energy awareness is an essential design issue. Routing protocols in WSNs might differ depending on the application and network architecture. In this article we present a survey of state of the art routing techniques in WSNs. We first outline the design challenges for routing protocols in WSNs followed by a comprehensive survey of routing techniques. Overall, the routing techniques are classified into three categories based on the underlying network structure: flit, hierarchical, and location based routing. Furthermore, these protocols can be classified into multipath based, query based, negotiation based, QoS based, and coherent based depending on the protocol operation. We study the design trade offs between energy and communication overhead savings in every routing paradigm. We also highlight the advantages and performance issues of each routing technique. The article concludes with possible future research areas.",
"author_names": [
"Jamal N Al-Karaki",
"Ahmed E Kamal"
],
"corpus_id": 1236072,
"doc_id": "1236072",
"n_citations": 4988,
"n_key_citations": 284,
"score": 0,
"title": "Routing techniques in wireless sensor networks: a survey",
"venue": "IEEE Wireless Communications",
"year": 2004
},
{
"abstract": "We propose a packet switched platform for single chip systems which scales well to an arbitrary number of processor like resources. The platform, which we call Network on Chip (NOC) includes both the architecture and the design methodology. The NOC architecture is a m/spl times/n mesh of switches and resources are placed on the slots formed by the switches. We assume a direct layout of the 2 D mesh of switches and resources providing physical and architectural level design integration. Each switch is connected to one resource and four neighboring switches, and each resource is connected to one switch. A resource can be a processor core, memory, an FPGA, a custom hardware block or any other intellectual property (IP) block, which fits into the available slot and complies with the interface of the NOC. The NOC architecture essentially is the onchip communication infrastructure comprising the physical layer, the data link layer and the network layer of the OSI protocol stack. We define the concept of a region, which occupies an area of any number of resources and switches. This concept allows the NOC to accommodate large resources such as large memory banks, FPGA areas, or special purpose computation resources such as high performance multi processors. The NOC design methodology consists of two phases. In the first phase a concrete architecture is derived from the general NOC template. The concrete architecture defines the number of switches and shape of the network, the kind and shape of regions and the number and kind of resources. The second phase maps the application onto the concrete architecture to form a concrete product.",
"author_names": [
"Shashi Kumar",
"Axel Jantsch",
"Mikael Millberg",
"Johnny Oberg",
"Juha-Pekka Soininen",
"Martti J Forsell",
"Kari Tiensyrja",
"Ahmed Hemani"
],
"corpus_id": 6599780,
"doc_id": "6599780",
"n_citations": 1299,
"n_key_citations": 64,
"score": 0,
"title": "A network on chip architecture and design methodology",
"venue": "Proceedings IEEE Computer Society Annual Symposium on VLSI. New Paradigms for VLSI Systems Design. ISVLSI 2002",
"year": 2002
}
] |
Doping silicon nanocrystals and quantum dots. | [
{
"abstract": "The ability to incorporate a dopant element into silicon nanocrystals (NC) and quantum dots (QD) is one of the key technical challenges for the use of these materials in a number of optoelectronic applications. Unlike doping of traditional bulk semiconductor materials, the location of the doping element can be either within the crystal lattice (c doping) on the surface (s doping) or within the surrounding matrix (m doping) A review of the various synthetic strategies for doping silicon NCs and QDs is presented, concentrating on the efficacy of the synthetic routes, both in situ and post synthesis, with regard to the structural location of the dopant and the doping level. Methods that have been applied to the characterization of doped NCs and QDs are summarized with regard to the information that is obtained, in particular to provide researchers with a guide to the suitable techniques for determining dopant concentration and location, as well as electronic and photonic effectiveness of the dopant.",
"author_names": [
"Brittany L Oliva-Chatelain",
"Thomas M Ticich",
"Andrew R Barron"
],
"corpus_id": 10446912,
"doc_id": "10446912",
"n_citations": 46,
"n_key_citations": 1,
"score": 1,
"title": "Doping silicon nanocrystals and quantum dots.",
"venue": "Nanoscale",
"year": 2016
},
{
"abstract": "Abstract As the most fundamental material for microelectronics, silicon (Si) has bourgeoned in the past more than half a century. However, given the indirect bandgap of Si, the use of Si in optoelectronics is relatively limited due to its mediocre optical absorption and rather poor optical emission. During many years of efforts for extending the use of Si in optoelectronics Si nanocrystals (NCs) that are one type of the most important Si nanostructures have attracted significant attention owing to their remarkable electronic and optical properties. Si NCs are actually crystalline Si nanoparticles, which may be called Si quantum dots if their size is smaller than ~10 nm. With the manipulation of the size, surface and doping of Si NCs great tunability for the light emission from Si NCs with the quantum yield of more than 60% has been realized. Based on the efficient light emission from Si NCs high performance Si NC light emitting devices have been demonstrated. In the meantime, the efficient light emission from Si NCs has also been utilized for synaptic simulations in neuromorphic computing and down shifting in photovoltaics. Broadband optical absorption ranging from the ultraviolet to mid infrared has been recently obtained for Si NCs mainly by taking advantage of doping. This has enabled the use of Si NCs in novel solar cells, photodetectors and optoelectronic synaptic devices. The continuous improvement of the electronic and optical properties of Si NCs has made Si NCs unfading Si materials for optoelectronics, contributing to the development of Si based optoelectronic integration.",
"author_names": [
"Zhenyi Ni",
"Shu Zhou",
"Shuangyi Zhao",
"Wenbing Peng",
"Deren Yang",
"Xiaodong Pi"
],
"corpus_id": 199178216,
"doc_id": "199178216",
"n_citations": 31,
"n_key_citations": 0,
"score": 0,
"title": "Silicon nanocrystals: unfading silicon materials for optoelectronics",
"venue": "Materials Science and Engineering: R: Reports",
"year": 2019
},
{
"abstract": "Silicon nanocrystals, also known as silicon quantum dots, are regarded as green alternatives to traditional quantum dots composed of heavy metal elements. While it is well known that the semiconductor properties of these materials can be tuned by doping with p/n type dopants (i.e. boron and phosphorus) there is a lack of systematic understanding of their potential environmental impact if released into the ecosystem. Here, we demonstrate that introduction of dopants, especially phosphorus, cause doped silicon nanocrystals to produce reactive oxygen species, resulting in significant toxicity to a model microorganism, Shewanella oneidensis MR 1. In addition, the interaction between bacteria cells and silicon nanocrystals was investigated using dark field microscopy and bio TEM. Interestingly, boron doped silicon nanocrystals tended to attach to the cell surface while this phenomenon was not observed for undoped or phosphorus doped silicon nanocrystals.",
"author_names": [
"Bo Zhi",
"Sadhana Mishra",
"Natalie V Hudson-Smith",
"Uwe R Kortshagen",
"Christy L Haynes"
],
"corpus_id": 106386338,
"doc_id": "106386338",
"n_citations": 9,
"n_key_citations": 0,
"score": 0,
"title": "Toxicity Evaluation of Boron and Phosphorus Doped Silicon Nanocrystals toward Shewanella oneidensis MR 1",
"venue": "",
"year": 2018
},
{
"abstract": "Doping with donor and acceptor impurities is an effective way to control light emission originated from quantum size effect in Si nanocrystals. Combined measurements of photoluminescence intensity and kinetics give valuable information on mechanisms of the doping influence. Phosphorus, boron, and nitrogen were introduced by ion implantation into Si+ implanted thermal SiO2 films either before or after synthesis of Si nanocrystals performed at Si excess of about 10 at. and annealing temperatures of 1000 and 1100 degrees C. After the implantation of the impurity ions the samples were finally annealed at 1000 degrees C. It is found that, independently of ion kind, the ion irradiation (the first stage of the doping process) completely quenches the photoluminescence related to Si nanocrystals (peak at around 750 nm) and modifies visible luminescence of oxygen deficient centers in the oxide matrix. The doping with phosphorus increases significantly intensity of the 750 nm photoluminescence excited by a pulse 337 nm laser for the annealing temperature of 1000 degrees C, while introduction of boron and nitrogen atoms reduces this emission for all the regimes used. In general, the effective lifetimes (ranging from 4 to 40 micros) of the 750 nm photoluminescence correlate with the photoluminescence intensity. Several factors such as radiation damage, influence of impurities on the nanocrystals formation, carrier impurity interaction are discussed. The photoluminescence decay is dominated by the non radiative processes due to formation or passivation of dangling bonds, whereas the intensity of photoluminescence (for excitation pulses much shorter than the photoluminescence decay) is mainly determined by the radiative lifetime. The influence of phosphorus doping on radiative recombination in Si quantum dots is analyzed theoretically.",
"author_names": [
"Alexey N Mikhaylov",
"David Tetelbaum",
"Vladimir A Burdov",
"Oleg N Gorshkov",
"A I Belov",
"D A Kambarov",
"Vladimir Alekseevich Belyakov",
"V K Vasiliev",
"Anatoly Kovalev",
"D M Gaponova"
],
"corpus_id": 8336566,
"doc_id": "8336566",
"n_citations": 17,
"n_key_citations": 1,
"score": 0,
"title": "Effect of ion doping with donor and acceptor impurities on intensity and lifetime of photoluminescence from SiO2 films with silicon quantum dots.",
"venue": "Journal of nanoscience and nanotechnology",
"year": 2008
},
{
"abstract": "Experimental results on photoluminescence spectra and kinetics obtained in the studies of SiO2 oxide layers nanostructured by ion implantation of silicon with subsequent doping and annealing are systematized. It is shown that phosporus doping by ion implantation leads to a severalfold increase in the intensity and decay time of nonstationary photoluminescence at l 750 nm because of an increase in the probability of radiative recombination at Si doped quantum dots and of passivation of dangling bonds at the nanocrystal matrix interfaces.",
"author_names": [
"A I Belov",
"Vladimir Alekseevich Belyakov",
"Vladimir A Burdov",
"A N Mikhailov",
"David Tetelbaum"
],
"corpus_id": 98708730,
"doc_id": "98708730",
"n_citations": 10,
"n_key_citations": 0,
"score": 0,
"title": "Phosphorus doping as an efficient way to modify the radiative interband recombination in silicon nanocrystals",
"venue": "",
"year": 2009
},
{
"abstract": "Doping of Si nanocrystals is an important topic in the emerging field of Si nanocrystals based all Si tandem solar cells. Boron doped Si nanocrystals embedded in a silicon dioxide matrix were realized by a co sputtering process, followed by high temperature annealing. The x ray photoelectron spectroscopy B 1s signal attributable to Si B (187 eV) and/or B B (188 eV) indicates that the boron may exist inside Si nanocrystals. A higher probability of effective boron doping was suggested for Si rich oxide films with a low oxygen content, Then, structural and optical properties were characterized with a focus on the effects of the boron content on Si quantum dots. The results show that as the boron content increases, the nanocrystal size is slightly reduced and the Si crystallization is suppressed. The photoluminescence intensity of the films is decreased as the boron content increases. This is due to boron induced defects and/or Auger processes induced by effective doping. These results can provide optimal conditions for future Si quantum dot based solar cells.",
"author_names": [
"Xiaojing Hao",
"Eun-Chel Cho",
"Chris Flynn",
"Y S Shen",
"Gavin Conibeer",
"M a Green"
],
"corpus_id": 39343997,
"doc_id": "39343997",
"n_citations": 72,
"n_key_citations": 1,
"score": 0,
"title": "Effects of boron doping on the structural and optical properties of silicon nanocrystals in a silicon dioxide matrix.",
"venue": "Nanotechnology",
"year": 2008
},
{
"abstract": "Silicon nanocrystal quantum dots in a dielectric matrix form a material with higher band gap than silicon, but still compatible with silicon technology. So far, devices using silicon nanocrystals have been realized either on silicon wafers, or using in situ doping in the superlattice deposition which may hinder the nanocrystal formation. In this paper, a vertical PIN device is presented which allows to investigated the electrical and photovoltaic properties of nanocrystal quantum dot layers. The device structure circumvents any influence of a substrate wafer or dopants and provides full flexibility in the material choice of both, i.e. electron and hole, contacts. Furthermore, not high temperature stable contact materials can be applied. Devices have been realized using SiC/Si nanocrystal multilayers as the i region and doped a SixC1 x:H layers as electron and hole contacts. First devices show open circuit voltage of up to 400mV.",
"author_names": [
"Philipp Loper",
"A Witzky",
"Andreas Hartel",
"Sebastian Gutsch",
"Daniel Hiller",
"Jan Christoph Goldschmidt",
"Stefan Janz",
"Stefan W Glunz",
"Margit Zacharias"
],
"corpus_id": 119368453,
"doc_id": "119368453",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Photovoltaic properties of silicon nanocrystals in silicon carbide",
"venue": "OPTO",
"year": 2012
},
{
"abstract": "While the literature for the doping of silicon quantum dots (QDs) and nanocrystals (NCs) is extensive, reports of doping their germanium analogs are sparse. We report a range of attempts to dope Ge QDs both during and post synthesis. The QDs have been characterized by TEM, XPS, and I/V measurements of SiO 2 coated QD thin films in test cells using doped Si substrates. The solution synthesis of Ge QDs by the reduction of GeCl 4 with LiAlH 4 results in Ge QDs with a low level of chlorine atoms on the surface; however, during the H 2 PtCl 6 catalyzed alkylation of the surface with allylamine, to enable water solubility of the Ge QDs, chlorine functionalization of the surface occurs resulting in p type doping of the QD. A similar location of the dopant is proposed for phosphorus when incorporated by the addition of PCl 3 during QD synthesis; however, the electronic doping effect is greater. The detected dopants are all present on the surface of the QD s type) suggesting a self purification process is operative. Attempts to incorporate boron or gallium during synthesis were unsuccessful.",
"author_names": [
"Brittany L Oliva-Chatelain",
"Andrew R Barron"
],
"corpus_id": 54619620,
"doc_id": "54619620",
"n_citations": 5,
"n_key_citations": 1,
"score": 0,
"title": "Experiments towards size and dopant control of germanium quantum dots for solar applications",
"venue": "",
"year": 2015
},
{
"abstract": "The analysis of original works devoted to preparation and investigation of nanocrystalline silicon (nc Si) films containing Si quantum dots (QDs) that exhibit photoluminescence (PL) within the range 1.4 3.2 eV at room temperature is presented. Thin films were prepared by pulse laser deposition (PLD) Offered by authors doping these nc Si films with gold in the growing process provided passivation of Si dangling bonds (DB) and some increase in the forbidden gap width of a barrier layer. Demonstrated are possibilities to explain and control stationary and kinetic characteristics of visible PL in the framework of the quantum dimensional model as well as radiative exciton annihilation with taking into account Si nanocrystals (NCs) size distribution pronounced in PL features.",
"author_names": [
"E B Kaganovich",
"Sergey V Svechnikov",
"E G Manoilov",
"I M Kizyak"
],
"corpus_id": 98503385,
"doc_id": "98503385",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Formation of photoluminescent properties inherent to silicon quantum dots",
"venue": "",
"year": 2006
},
{
"abstract": "The question about the mechanisms of the photoluminescence enhancement of the system of silicon nanocrystals embedded into silica matrix at phosphorus doping is described. Both the experimental and theoretical arguments are presented.",
"author_names": [
"David Tetelbaum",
"Vladimir A Burdov",
"Alexey N Mikhaylov",
"Sergei A Trushin"
],
"corpus_id": 98041047,
"doc_id": "98041047",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "About the phosphorus sensitization of silicon quantum dots in SiO2 photoluminescence",
"venue": "Saratov Fall Meeting",
"year": 2003
}
] |
High Order Bragg grating semiconductor laser narrow lineWidth | [
{
"abstract": "Abstract In order to obtain narrow linewidth semiconductor laser around 1564 nm, we design a distributed Bragg reflector (DBR) laser with high order Bragg gratings (HOBGs) using butterfly encapsulation. The DBR laser is fabricated only by i line lithography technology with grating period of 4. 84 m m groove width of 1. 5 m m and grating length of 72 m m on a strip width of 4 m m The 1mm long devices achieved an output power of 9.9 mW and a side mode suppression ratio (SMSR) more than 30 dB without facet coating at an injection current of 80 mA. The lasers showed ultra narrow Lorentz linewidth of 70 kHz. This paper provides a simple method for large scale production of narrow linewidth semiconductor lasers.",
"author_names": [
"Hong Chen",
"Peng Jia",
"Chao Chen",
"Li Qin",
"Yongyi Chen",
"Youwen Huang",
"Yongqiang Ning",
"Lijun Wang"
],
"corpus_id": 146087549,
"doc_id": "146087549",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Narrow linewidth DBR laser based on high order Bragg grating defined by i line lithography",
"venue": "Optics Communications",
"year": 2019
},
{
"abstract": "In order to obtain narrow linewidth semiconductor laser around 1564 nm, we design a distributed Bragg reflector (DBR) laser based on surface etched high order Bragg gratings (SE HOBGs) To achieve C band Bragg resonance wavelength selection, the laser is designed as a grating period of 4.84 mm, an etched groove depth of 1.2 mm, a grating duty cycle of 69% a total grating length of 72 mm, and a ridge waveguide width of 4.0 mm. For the DBR laser with cavity length of 1 mm, the output power reaches to 9.9 mW/facet and a 1564 nm laser output with a side mode suppression ratio (SMSR) more than 30 dB at an injection current of 80 mA. We measured and analyzed the phase/frequency noise, linewidth characteristics and the relative intensity noise (RIN) characteristics of the laser in detail. The lasers showed narrow Lorentz linewidth of 70 kHz. This paper provides a simple method for large scale production of narrow linewidth semiconductor lasers.",
"author_names": [
"Chao Chen",
"Peng Jia",
"Li Qin",
"Yongyi Chen",
"Hong Chen",
"Yongqiang Ning",
"Li-jun Wang"
],
"corpus_id": 209654776,
"doc_id": "209654776",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Noise and linewidth characterizations of DBR laser based on surface etched high order Bragg gratings",
"venue": "Applied Optics and Photonics China",
"year": 2019
},
{
"abstract": "Abstract Surface emitting distributed feedback (SE DFB) semiconductor laser has become one of study hotspots due to its narrow linewidth and high power. Herein, a SE DFB semiconductor laser is proposed based on second order Bragg grating for feedback and out coupling. The grating is fabricated on the confinement layer, which can realize the laser emission from the substrate and avoid the secondary epitaxial growth. The asymmetric waveguide structure is introduced into the device to increase the probability of photon and grating interaction while reducing the threshold current. The results show that when the current is 3A, the output laser power from the substrate achieves 1.22 W. In the meantime, the threshold current, voltage and slope efficiency are 300 mA, 1.73 V and 0.45 W/A, respectively. The center wavelength is 980.1 nm and the linewidth is 0.84 nm. This work has important implications for low threshold current narrow linewidth SE DFB semiconductor lasers.",
"author_names": [
"Yina Hai",
"Yong-gang Zou",
"Xiaohui Ma",
"Haizhu Wang",
"Lingni Zhu"
],
"corpus_id": 228908360,
"doc_id": "228908360",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Narrow linewidth surface emitting distributed feedback semiconductor lasers with low threshold current",
"venue": "",
"year": 2021
},
{
"abstract": "We demonstrate ultra narrow linewidth fixed wavelength hybrid lasers composing a semiconductor gain chip and extended silicon nitride Bragg grating. Fabricated ultra low k Bragg gratings provide a narrow bandwidth and high side lobe suppression ratio. A single wavelength 1544 nm hybrid extended distributed Bragg reflector laser with 24 mW output power and a Lorentzian linewidth of 320 Hz is demonstrated, providing a high performance light source for on and off chip applications.",
"author_names": [
"Chao Xiang",
"Paul Adrian Morton",
"John E Bowers"
],
"corpus_id": 199057174,
"doc_id": "199057174",
"n_citations": 32,
"n_key_citations": 0,
"score": 1,
"title": "Ultra narrow linewidth laser based on a semiconductor gain chip and extended Si3N4 Bragg grating.",
"venue": "Optics letters",
"year": 2019
},
{
"abstract": "We describe a simple, narrow linewidth, tunable fiber based laser with a high degree of tuning accuracy. A polarization independent semiconductor optical amplifier (SOA) is used as the gain medium in a unidirectional fiber ring cavity with a circulator connected to a 6 meter long chirped fiber Bragg grating (CFBG) The laser wavelength is chosen by setting the modulation frequency of the SOA the same as the harmonics of the fundamental repetition rate of the light reflected at a specific point on the CFBG. Careful management of the drive current and pulse width helps to generate laser light of narrow linewidth (less than 0.03 nm) with low power variation (1.46 dB) over a tuning range of 40 nm.",
"author_names": [
"Xiong Yang",
"Robert Lindberg",
"Walter Margulis",
"Krister Frojdh",
"F Laurell"
],
"corpus_id": 155283272,
"doc_id": "155283272",
"n_citations": 6,
"n_key_citations": 0,
"score": 0,
"title": "Continuously tunable, narrow linewidth laser based on a semiconductor optical amplifier and a linearly chirped fiber Bragg grating.",
"venue": "Optics express",
"year": 2019
},
{
"abstract": "We experimentally demonstrate an all fiber high power fiber amplifier with high beam quality and a slope efficiency of 81.8% using a fiber Bragg grating stabilized laser diode as a narrow spectral linewidth (0.08 nm) seed source. During amplification, the spectral linewidth of the laser output is broadened from 0.08 to 0.24 nm due to nonlinear phenomena. To the best of our knowledge, we report the first experimental observation of the suppression of stimulated Brillouin scattering (SBS) with increased output power. In addition, we investigated the SBS suppression by simultaneously measuring the optical backscattered power, backscattered spectrum, and output spectrum at different values of output power. The beam quality, M2, was measured to be ~1.28 at the maximum output power of 2.05 kW, and modal instability was not observed.",
"author_names": [
"Junsu Lee",
"Kwang Hyun Lee",
"Hwanseong Jeong",
"Minkyu Park",
"Jihoon Seung",
"Jung Hwan Lee"
],
"corpus_id": 201272187,
"doc_id": "201272187",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "2.05 kW all fiber high beam quality fiber amplifier with stimulated Brillouin scattering suppression incorporating a narrow linewidth fiber Bragg grating stabilized laser diode seed source.",
"venue": "Applied optics",
"year": 2019
},
{
"abstract": "Abstract We demonstrated a narrow linewidth monolithic fiber Bragg grating based (FBG based) MOPA configuration fiber laser with a high power spectral density (PSD) In the oscillator, long grating length FBG with narrow reflection bandwidth was employed, combined with a short length resonant cavity, contributing to a narrow linewidth high PSD seed laser. In the amplifier stage, methods were taken to suppress spectrum broadening, such as large core active fiber and wavelength stabilized laser diode. As a result, the fiber laser achieved an output power of 3010 W, a spectral 3 dB bandwidth of 103 pm, and a PSD of 29.3 pm/kW. To the best of our knowledge, this is the highest PSD reported by an all fiber FBG based fiber laser.",
"author_names": [
"Yusheng Huang",
"Qirong Xiao",
"Dan Li",
"Jingtao Xin",
"Zehui Wang",
"Jiading Tian",
"Yulun Wu",
"Mali Gong",
"Lianqing Zhu",
"Ping Yan"
],
"corpus_id": 225019132,
"doc_id": "225019132",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "3 kW narrow linewidth high spectral density continuous wave fiber laser based on fiber Bragg grating",
"venue": "",
"year": 2021
},
{
"abstract": "A PQ PMMA Bragg grating served as one of the cavity mirrors in an external V shaped laser cavity using a tapered amplifier as the gain medium. The laser achieves singe longitudinal mode with the output power exceed 600 mW, and has 30 nm tunable spectral range.",
"author_names": [
"Yu-Hua Hsieh",
"Te-yuan Chung",
"Longlong Du",
"Shiuan Huei Lin"
],
"corpus_id": 136922409,
"doc_id": "136922409",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "A High Power, Narrow Linewidth and Wavelength Tunable Semiconductor Laser Using a Photopolymer Bragg Grating as One of the Cavity Mirrors",
"venue": "",
"year": 2014
},
{
"abstract": "We demonstrate a tunable narrow linewidth laser based on a semiconductor optical amplifier and a linearly chirped FBG. High tuning resolution and small power variation over 40 nm tuning range were achieved by optimizing the drive current. (c) 2019 The Author(s)",
"author_names": [
"Xiong Yang",
"Robert Lindberg",
"Walter Margulis",
"Krister Frojdh",
"F Laurell"
],
"corpus_id": 164471727,
"doc_id": "164471727",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Rapid and Continuously Tunable Narrow Linewidth Fiber Source Based on a SOA and a Linearly Chirped Fiber Bragg Grating",
"venue": "2019 Conference on Lasers and Electro Optics (CLEO)",
"year": 2019
},
{
"abstract": "We demonstrate a tunable narrow linewidth laser based on a semiconductor optical amplifier and a linearly chirped FBG. High tuning resolution and small power variation over 40 nm tuning range were achieved by optimizing the drive current. (c) 2019 The Author(s)",
"author_names": [
"Xiong Yang",
"Robert Lindberg",
"Walter Margulis",
"Krister Frojdh",
"F Laurell"
],
"corpus_id": 203070067,
"doc_id": "203070067",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Rapid and Continuously Tunable Narrow Linewidth Fiber Source Based on a SOA and a Linearly Chirped Fiber Bragg Grating",
"venue": "",
"year": 2019
}
] |
business in networks | [
{
"abstract": "Preface. Chapter 1 A Jungle or a Rainforest? 1.1 A changing business landscape. 1.2 The necessity and danger with metaphors related to the business world. The business world as a jungle populated by competing rivals. The business world as a co evolving rainforest. 1.3 The content and disposition of the book. Part 1 Business Networks in Action. Chapter 2 Interaction as a way to deal with Relatedness, Variety, and Motion. 2.1 A Need for a Different Theoretical Approach. 2.2 A Business Landscape Populated by Interacting Companies. 2.3 Interaction and the Larger Business Landscape. Chapter 3 Analyzing Business Interation. 3.1 The Idea of Business Interaction. 3.2 Interaction Processes Between Companies. 3.3. An Initial Conceptualization of Interaction. 3.4 The A R A Model. 3.5 Interaction and Time. 3.6 Interaction and Space. 3.7 A Model of the Interaction Process. 3.8 Conclusions. Chapter 4 Doing Business: Exploiting Time and Space. 4.1 Using Time and Space. 4.2 Interaction as a Way to Take Advantage of Development Over Time. 4.3 Interaction as a Way to Take Advantage of Development Over Space. 4.4 The Company in the Interactive Business Landscape. Part 2 The Elements of Business Networks. Chapter 5 Interaction and Resources. 5.1. Economic Resources in the IMP Framework. 5.2. An Initial View of Resources in an Interactive Business Landscape. 5.3 Resources and Business: Basic Propositions. 5.4 An Interactive World Full of Resources. 5.5 Combining new and existing resources. 5.6 Resources and their multiple contexts. 5.7 Tensions between resources. 5.8 Business relationships and resource development and use. 5.9 Resources in Time and Space. 5.10 Concluding remarks. Chapter 6 Interaction and Activities. 6.1 An Interactive Business Landscape Full of Activities. 6.2 Basic Propositions About the Nature of Activities. 6.3 Key Issues in Activity Configuration. 6.4 Central Features of Activities. 6.5 A Framework for Analysis of Activity Patterns. 6.6 Balancing in Activity Patterns Three Empirical Illustrations. 6.7 Concluding the Chapter. Chapter 7 Interaction and Actors. 7.1 Actors in an Interactive Landscape. 7.2 Actors in the IMP Research. 7.3 The Idea of Actors. 7.4 Distinctive Features. 7.5 Analysing Acting Actors. 7.6 Challenges in Conceptualizing Actors. 7.7 Final Considerations. Part 3 The Business Network as an Analytical Tool. Chapter 8 Management and Business Relationships. 8.1 Outline and Introduction. 8.2 When Management Theory is Coloured by the Idea of a Market. 8.3 When Relationships are Observed From a Market Based Management Perspective. 8.4. Conclusions Relationships and Still a Market? Chapter 9 Managing in the Business Network. 9.1 Introduction. 9.2 The Start The Relationship as a Unit of Analysis. 9.3 How Do Companies Interact? 9.4 How Should Companies Interact? 9.5 Managing and the Interacting Company. 9.6 Managerial Patterns in Business Networks. 9.7 Conclusions. Chapter 10 Evolution of the Business Landscape. 10.1 Introduction. 10.2 Time and the Business Landscape. 10.3 The Narrative of the Evolution of Economic organizing. 10.4 Re interpreting Business Evolution. 10.5 A Network View of Business Evolution. 10.6 Concluding Discussion. Chapter 11 Networks and Industrial Policy. 11.1 Networks One Word But Many Meanings. 11.2 What Principles are Network Policies Resting on? 11.3 The Taiwanese Semiconductor Development From Virgin Land to a Successful Business Network? 11.4 The Heaviness of Business Networks. 11.5 What's in the Shadow of a Successful Network? 11.6 The Dark Sides of Networks. 11.7 The Different Logics of Development, Production and Use. Chapter 12 Living in the Business Rainforest. 12.1 The Rainforest Metaphor. 12.2 Living in the Rainforest. 12.3 The Entrepreneur and the Business Rainforest. 12.4 The CEO and the Business Rainforest. 12.5 The Financial Accountant and the Business Rainforest. 12.6 The Consumer and the Business Rainforest. 12.7 The Politician and the Business Rainforest. 12.8 Conclusions. References. Index.",
"author_names": [
"Hakan Hakansson",
"David Ford",
"Lars-Erik Gadde",
"Ivan Snehota",
"Alexandra Waluszewski"
],
"corpus_id": 67748347,
"doc_id": "67748347",
"n_citations": 285,
"n_key_citations": 24,
"score": 1,
"title": "Business Networks",
"venue": "Encyclopedia of Social Network Analysis and Mining. 2nd Ed.",
"year": 2018
},
{
"abstract": "This edited collection applies the network approach to the analysis of business relationships in a global context. Drawing on a number of international case studies, a \"network approach\" is developed, giving rise to theoretical and practical managerial insights and a different way of conceptualizing companies within markets. New angles emerge on traditional problems of business management, with some novel implications which should challenge established ways to analyze business markets. Previous publications by these authors include, \"Corporate Technological Behaviour\" \"Professional Purchasing\" and \"Managing Innovation Within Networks\"",
"author_names": [
"Hakan Hakansson",
"Ivan Snehota"
],
"corpus_id": 166373276,
"doc_id": "166373276",
"n_citations": 3493,
"n_key_citations": 291,
"score": 0,
"title": "Developing relationships in business networks",
"venue": "",
"year": 1995
},
{
"abstract": "Predictive business process monitoring methods exploit logs of completed cases of a process in order to make predictions about running cases thereof. Existing methods in this space are tailor made for specific prediction tasks. Moreover, their relative accuracy is highly sensitive to the dataset at hand, thus requiring users to engage in trial and error and tuning when applying them in a specific setting. This paper investigates Long Short Term Memory (LSTM) neural networks as an approach to build consistently accurate models for a wide range of predictive process monitoring tasks. First, we show that LSTMs outperform existing techniques to predict the next event of a running case and its timestamp. Next, we show how to use models for predicting the next task in order to predict the full continuation of a running case. Finally, we apply the same approach to predict the remaining time, and show that this approach outperforms existing tailor made methods.",
"author_names": [
"Niek Tax",
"Ilya Verenich",
"Marcello La Rosa",
"Marlon Dumas"
],
"corpus_id": 2192354,
"doc_id": "2192354",
"n_citations": 253,
"n_key_citations": 53,
"score": 0,
"title": "Predictive Business Process Monitoring with LSTM Neural Networks",
"venue": "CAiSE",
"year": 2017
},
{
"abstract": "We introduce a literature review considering articles on artificial neural networks in business published in last two decades.412 suitable articles are identified and classified according to defined methodology.We focus on date, area of interest, type of neural network, benchmark method, journal and citations.The most applied are multilayer feedforward networks with backpropagation learning performed by gradient descent algorithm.Majority (25.73% of the examined articles were published in Expert Systems with Applications. In recent two decades, artificial neural networks have been extensively used in many business applications. Despite the growing number of research papers, only few studies have been presented focusing on the overview of published findings in this important and popular area. Moreover, the majority of these reviews were introduced more than 15 years ago. The aim of this work is to expand the range of earlier surveys and provide a systematic overview of neural network applications in business between 1994 and 2015. We have covered a total of 412 articles and classified them according to the year of publication, application area, type of neural network, learning algorithm, benchmark method, citations and journal. Our investigation revealed that most of the research has aimed at financial distress and bankruptcy problems, stock price forecasting, and decision support, with special attention to classification tasks. Besides conventional multilayer feedforward network with gradient descent backpropagation, various hybrid networks have been developed in order to improve the performance of standard models. Even though neural networks have been established as well known method in business, there is enormous space for additional research in order to improve their functioning and increase our understanding of this influential area.",
"author_names": [
"Michal Tkac",
"Robert Verner"
],
"corpus_id": 205707258,
"doc_id": "205707258",
"n_citations": 191,
"n_key_citations": 7,
"score": 0,
"title": "Artificial neural networks in business: Two decades of research",
"venue": "Appl. Soft Comput.",
"year": 2016
},
{
"abstract": "Abstract This article introduces the Special Issue of Managing Business and Innovation Networks and makes an independent contribution to the advancement of network management research. The study has three ambitious goals. First, it evaluates the main developments in network management research from 2000 to 2016, focusing on disciplinary openings. Second, it specifies the contributions of recent domain extensions (business fields, ecosystems, platform networks) to network management, and clarifies the role of networks and network management in these domains. Third, it proposes a general theory of network management based on the past 20 years of research in the field and the contributions of SI articles. The theory explains how the factors at three contextual levels environment, network and actor influence network management activities, forming patterns of management based on activity configurations. The framework consolidates our fragmented knowledge on network management and paves the way for more advanced research and management. We conclude with suggestions for future research.",
"author_names": [
"Kristian Moller",
"Aino Halinen"
],
"corpus_id": 168753281,
"doc_id": "168753281",
"n_citations": 93,
"n_key_citations": 4,
"score": 0,
"title": "Managing business and innovation networks From strategic nets to business fields and ecosystems",
"venue": "",
"year": 2017
},
{
"abstract": "This paper is concerned with business model conceptualizations and outlines a framework for their analysis in industrial networks. A literature review suggests that there is a broad range of current conceptualizations of business models. Analyzing them as they pertain to interaction, business relationships, and industrial networks reveals two main explanations for their differences: first, they clearly rely on different basic theoretical assumptions, and second, they seem to address two types of business models. We refer to these as firm centric and network embedded business models. Based on this distinction, a scheme of analysis at the levels of the firm, relationship and network is suggested for the two types of business models. Business models are challenging from an analytical as well as managerial perspective. Further research on emerging network embedded business models is suggested",
"author_names": [
"Lars Bankvall",
"Anna Dubois",
"Frida Lind"
],
"corpus_id": 167338823,
"doc_id": "167338823",
"n_citations": 51,
"n_key_citations": 6,
"score": 0,
"title": "Conceptualizing business models in industrial networks",
"venue": "",
"year": 2017
},
{
"abstract": "",
"author_names": [
"Morten T Hansen",
"Michael A Hitt"
],
"corpus_id": 14512942,
"doc_id": "14512942",
"n_citations": 1825,
"n_key_citations": 198,
"score": 0,
"title": "Knowledge Transfer in Intraorganizational Networks Effects of Network Position and Absorptive Capacity on Business Unit Innovation and Performance",
"venue": "",
"year": 2007
},
{
"abstract": "Abstract Although informal knowledge networks have often been regarded as a key ingredient behind the success of industrial clusters, the forces that shape their structure and dynamics remain largely unknown. Drawing on recent network dynamic models, we analyze the evolution of business and technical knowledge networks within a toy cluster in Spain. Empirical results suggest that the dynamics of the two networks differ to a large extent. We find that status drives the formation of business knowledge networks, proximity is more crucial for technical knowledge networks, while embeddedness plays an equally important role in the dynamics of both networks.",
"author_names": [
"Pierre-Alexandre Balland",
"Jose Antonio Belso-Martinez",
"Andrea Morrison"
],
"corpus_id": 150594443,
"doc_id": "150594443",
"n_citations": 106,
"n_key_citations": 5,
"score": 0,
"title": "The Dynamics of Technical and Business Knowledge Networks in Industrial Clusters: Embeddedness, Status, or Proximity?",
"venue": "",
"year": 2016
},
{
"abstract": "Abstract The era of social media networks has created significant opportunities for business relationship development yet there exists a paucity of research in this area. To address this, this paper identifies four key tensions within the current literature: relational versus transactional exchanges, emergent versus strategic social media network development, the pace of social media network formation versus the development of trust, and the notions of sharing and reciprocity versus competitive advantage. This study draws on the principles of netnography, incorporating data from 554 LinkedIn group interactions and 12 interviews with professionals in one global industry to provide insight into business relationship development stemming from one social media network. Significant contributions to theoretical and practical knowledge are made through the recognition of tensions in the literature, the application of the notion of Granovetter's ties to a contemporary context and the novel use of netnography. Furthermore, the resultant model conceptualises the use of social media networking in building networks and relationships which lead to new business and enhance business performance.",
"author_names": [
"Sarah Quinton",
"Damien Wilson"
],
"corpus_id": 167451972,
"doc_id": "167451972",
"n_citations": 85,
"n_key_citations": 6,
"score": 0,
"title": "Tensions and ties in social media networks: Towards a model of understanding business relationship development and business performance enhancement through the use of LinkedIn",
"venue": "",
"year": 2016
},
{
"abstract": "Inside a multiunit organization, units can learn from each other and benefit from new knowledge developed by other units. Knowledge transfer among organizational units provides opportunities for mutual learning and interunit cooperation that stimulate the creation of new knowledge and, at the same time, contribute to organizational units' ability to innovate (e.g. Kogut Zander, 1992; Tsai",
"author_names": [
"Wenpin Tsai"
],
"corpus_id": 167329304,
"doc_id": "167329304",
"n_citations": 2206,
"n_key_citations": 68,
"score": 0,
"title": "Knowledge Transfer in Intraorganizational Networks: Effects of Network Position and Absorptive Capacity on Business Unit Innovation and Performance",
"venue": "",
"year": 2001
}
] |
QFN process flow | [
{
"abstract": "Package thinning, down scaling, and miniaturization are common interests among semiconductor industries, with each manufacturing site having different approach and technical directions in providing novelties in their products. The paper offers an innovative design of manufacturing flow to reduce the semiconductor package height of a Quad Flat No leads (QFN) device through the application of a specialized package grinding process. The process would significantly reduce the carrier thickness for the overall package height configuration of QFN. Through this integration, the common assembly barriers and defects related in producing thin devices are eliminated, thus thinner version manufacturing becomes more simplified and efficient.",
"author_names": [
"Rennier S Rodriguez",
"Frederick Ray I Gomez"
],
"corpus_id": 210895634,
"doc_id": "210895634",
"n_citations": 7,
"n_key_citations": 0,
"score": 1,
"title": "Incorporating Package Grinding Process for QFN Thin Device Manufacturing",
"venue": "",
"year": 2020
},
{
"abstract": "This research studied about an epoxy molding compound (EMC) floor life to reliability performance of integrated circuit (IC) package. Molding is the process for protecting the die of IC package form mechanical and chemical reaction from external environment by shaping EMC. From normal manufacturing process, the EMC is stored in the frozen at 5oC and left at around room temperature for aging time or floor life before molding process. The EMC floor life effect to its properties and reliability performance of IC package. Therefore, this work interested in varied the floor life of EMC before molding process to analyze properties of EMC such as spiral flow length, gelation time, and viscosity. In experiment, the floor life of EMC was varied to check the effect of its property to reliability performance. The EMC floor life were varied from 0 hours to 60 hours with a step of 12 hours and observed wire sweep, incomplete EMC, and delamination inside the packages for 3x3, 5x5 and 8x8 mm2 of QFN packages. The evaluation showed about clearly effect of EMC floor life to IC packaging reliability. EMC floor life is not any concern for EMC property, moldabilty, and reliability from 0 hours to 48 hours for molding process of 3x3,5x5 and 8x8 mm2 QFN packaging manufacturing",
"author_names": [
"Udom Peanpunga",
"Kessararat Ugsornrat",
"Panakamol Thorlor",
"Chalermsak Sumithpibul"
],
"corpus_id": 139554484,
"doc_id": "139554484",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "The Effect of Epoxy Molding Compound Floor Life to Reliability Performance and mold ability for QFN Package",
"venue": "",
"year": 2017
},
{
"abstract": "The development of solutions for high power packaging systems requires the use of a die attach material that has high thermal conductivity and low electrical resistance. However, solder paste, one of which meets this design requirement, is often affected by solder voids that form during the reflow process. By using a 3 factor full factorial design of experiment, this study looks into the effects of reflow profile, nitrogen flow rate, and leadframe type (A and B) on single and cumulative voids produced during the reflow process. Also, the effect of the location of specific nitrogen vents in the machine with respect to the package during reflow processing will be discussed. Analysis of data collected shows that use of higher N2 flow rate, leadframe type A, and reflow profile with higher time above liquidus and soak time reduces both single and cumulative void dppm by more than 95% This is attributed to lower oxidation and increased flux outgassing during solder reflow.",
"author_names": [
"Ariel Jan V Sadural",
"Laura May Antoinette Clemente"
],
"corpus_id": 34779425,
"doc_id": "34779425",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Voiding reduction and leadframe interactions in high lead solder die attach for QFN applications",
"venue": "2017 International Conference on Electronics Packaging (ICEP)",
"year": 2017
},
{
"abstract": "A quad flat no lead (QFN) package delamination improvement and its related lead frame (LF) copper oxidation effect were studied. Pudding mold adhesion testing method was utilized to determine the epoxy molding compound (EMC)/LF interfacial adhesion performance, chemical composition change including cupric oxide (CuO, Cu+ and cuprous oxide (Cu2O, Cu+ on LF surface oxidation structure was identified by Auger electron spectroscopy (AES) Experimental results have shown that higher CuO/Cu2O ratio (Cu+/Cu+ 1) have a good adhesion characterization for different oxidizing observation, moreover, AES depth profile analysis have supported that the demonstration much CuO content to reduction is verified an important adhesion improvement after plasma clean process. Back end plasma clean conditions such as plasma time, slot/un lot magazine type, and H2/Ar mixing gas flow rate in a QFN package production for enhancing adhesion characterization were studied, moreover, a package delamination improvement was obtained by plasma clean conditions tuning.",
"author_names": [
"M F Shu",
"Koduck Chen",
"Bret Yang",
"Webber Liu",
"Yi-Hsiu Tseng"
],
"corpus_id": 30707609,
"doc_id": "30707609",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Lead frames copper oxidation effect for a QFN package delamination improvement",
"venue": "2016 6th Electronic System Integration Technology Conference (ESTC)",
"year": 2016
},
{
"abstract": "Automotive IC demand is expected to grow tremendously at CAGR of 7% over the next few years. In general automotive devices can be packaged into commonly used packaging solution like SOIC, SOP, QFN, except a few automotive products may require custom packaging solution. This paper discuss the QFN packaging solution for automotive IC from the perspective of package outline design, material selection, process flow, manufacturing system control and reliability assessment. It also covers special topics of research on side wall plating and packaging design and process consideration for more stringent \"under the hood\" grade 0 automotive products.",
"author_names": [
"Tan Boo Wei",
"Lee Yoke Foo",
"Niu You Hua"
],
"corpus_id": 5918412,
"doc_id": "5918412",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Automotive QFN packaging solution",
"venue": "2016 China Semiconductor Technology International Conference (CSTIC)",
"year": 2016
},
{
"abstract": "High end test handler with high efficiency is required in domestic.Through consulting many documents and researching test handler using turntable of import carefully,system design of TX900 quad flat no lead package test handler was drawn up.The work principle of TX900 QFN test handler was discussed.Running process of the machine was described.The system structure model was built with modular design method.The structure design of all parts was illustrated in detail.The structure of electronic control and design of control software were introduced.The flow chart of control program was presented.At last key technologies and solutions of the machine were discussed.The machine is efficient,compatible and extensible.The whole system design lays a foundation for the realization of the QFN test handler using turntable.",
"author_names": [
"Cao Pan-jiang"
],
"corpus_id": 112760823,
"doc_id": "112760823",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "System design of QFN test handler using turntable",
"venue": "",
"year": 2010
},
{
"abstract": "The chip embedding technology achieved significant progress the last years. After various research activities the main focus is today on industrialisation and implementation of new business models. In the project HERMES European partners from industry and research aim to bring embedding technology based on low cost PCB /Printed Circuit Board) processes to a market ready product flow, demonstrated by automotive, power electronics and telecommunication applications. The research part of the project aims to overcome current limitations and to achieve even higher levels of miniaturisation. This paper will describe the embedding process flow and will discuss the process steps in detail. Three devices realised, a 2 chip module, a 3D System in Package and a QFN (Quad Flat No Lead) package will be described and discussed. Especially the realisation of the QFN is a strong challenge for today's machine capabilities, since it contains a chip with a pitch of 100 um.",
"author_names": [
"Andreas Ostmann",
"Dionysios Manessis",
"Lars Boettcher",
"Stefan Karaszkiewicz",
"Herbert Reichl"
],
"corpus_id": 43360587,
"doc_id": "43360587",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Realisation of embedded chip QFN packages technological challenges and achievements",
"venue": "2009 European Microelectronics and Packaging Conference",
"year": 2009
},
{
"abstract": "Miniaturized package with thinner die requirement like Quad Flat No Lead (QFN) has led to new challenges for conventional die attach paste materials and dicing process. Die attach film (DAF) is seem to be the most potential candidate to replace the conventional die attach paste for QFN stacked die. DAF is able to replace epoxy paste in stacked packages in producing good paste bleed control, zero creeping effect and constant bond line thickness (BLT) Dicing die attach film (DDAF) will be used in this study; the laminated DDAF wafer will be diced together during wafer dicing. Laminated wafer will be cut by using step cut method. In dicing DDAF, parameter such as spindle rotation, feed speed, water flow and blade grit size will be considered. However, dicing DDAF laminated wafer is not as simple as the bare silicon wafer. Due to this reason, this paper will reveal the DDAF dicing response. Dicing responses like lateral crack, whisker formation and sidewall effect will be observed. The result shows that step cutting process gives the common dicing effect which is still in the accepted limit. In addition, the implementation of controlling dicing process parameter is crucial to obtain good dicing results.",
"author_names": [
"Samihah Abdullah",
"S M Yusof",
"Azman Jalar",
"Mohamad Faizal Abdullah",
"Zalina Abdul Aziz",
"Ruslizam Daud"
],
"corpus_id": 114427102,
"doc_id": "114427102",
"n_citations": 6,
"n_key_citations": 0,
"score": 0,
"title": "STEP CUT FOR DICING LAMINATED WAFER IN A QFN PACKAGE",
"venue": "",
"year": 2008
},
{
"abstract": "Quad Flat No Lead Package (QFN) with \"Super Thin\" package height of 0.3 to 0.4 mm (package profile height sub code \"X2\" per Jedec Standard) is designed with limited vertical space for wire loop height. Typical package construction consists of leadframe thickness, chip and chip attach adhesive thickness, mold (encapsulation) thickness left only 75 to 100 um (3 to 4 mils) space between chip surface and package surface which is available for wire bonding Therefore wire bonding loop height in QFN X2 package are typically controlled within less than 100um (4mils) as measured from chip surface to highest point of wire loop Typically there are 3 areas to consider when developing gold wire bond techniques to achieve low loop height: 1. Stress level at the heat affected zone near wire exit above ball (1st bonds) 2. Consistency of wire loop height across all wires within same package. 3. Resistance to mold flow sweeping during molding (encapsulation process) There are two common wire bond techniques available to achieve wire loop height less than 100um (4mils) bond stitch on ball (BSOB) and ultra low loop (ULL) forward bonding. This paper discusses the comparative performance and limitations of both wire bond techniques",
"author_names": [
"Tan Boo Wei",
"Wang Lei",
"Ken Niu",
"Lu Hai Long"
],
"corpus_id": 24331294,
"doc_id": "24331294",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Application Of Ultra Low Loop gold wire bonding technique in Super Thin (Jedec Package Profile Height Sub Code \"X2\" Quad Flat No Lead Package (QFN)",
"venue": "2008 33rd IEEE/CPMT International Electronics Manufacturing Technology Conference (IEMT)",
"year": 2008
},
{
"abstract": "This paper elaborates on the EMC leadframe interfacial delamination in QFN package. The study was conducted to check each factor and process which contributes to the package delamination. A list of the possible process/factor and their impact on the package interfacial delamination were first determined through brainstorming. Fractional factorial screening experiment was then conducted to determine the vital few factors in the current process flow from the trivial many by incorporating the blocking concept on material batch to batch and machine to machine variation. The screening experiment shows the metal finishing process is the major contributor for delamination. Further each cell in metal finishing process was studied and step by step root cause identification was done. Statistical Analysis was used to determine each affecting factor for delamination. This report discusses the detail DOE to identify the root cause for interfacial delamination.",
"author_names": [
"Teo Soon Tong",
"J Sharath Kumar",
"M M D Kanan"
],
"corpus_id": 25161447,
"doc_id": "25161447",
"n_citations": 4,
"n_key_citations": 1,
"score": 0,
"title": "A Study and Investigation on Processes Inducing Delamination in QFN Package Using Statistical Analysis",
"venue": "2006 Thirty First IEEE/CPMT International Electronics Manufacturing Technology Symposium",
"year": 2006
}
] |
2d simulation of chemotaxis bacteria aggregation | [
{
"abstract": "We start from a mathematical model which describes the collective motion of bacteria taking into account the underlying biochemistry. This model was first introduced by Keller Segel A new formulation of the system of partial differential equations is obtained by the introduction of a new variable (this new variable is similar to the quasi Fermi level in the framework of semiconductor modelling) This new system of P.D.E. is approximat ed via a mixed finite element technique. The solution algorithm is then described and finally we give some preliminary numerical results.Especially our method is well adapted to compute the concentration of bacteria.",
"author_names": [
"A Marrocco"
],
"corpus_id": 103085683,
"doc_id": "103085683",
"n_citations": 9,
"n_key_citations": 0,
"score": 1,
"title": "2D simulation of chemotactic bacteria aggregation",
"venue": "",
"year": 2002
},
{
"abstract": "We use the the Monte Carlo method to calculate the net displacement of an aggregation of bacteria that are under interaction and exerting each other electric forces as consequence of communications among them. Thus starting from the fact that bacterium's ions are exerting repulsion or attraction to others bacteria belonging the same population, is a cause to impulse motility or mobility of the population. It also might be a property of the whole aggregation to determine decisions that maintain their wellness and protection against antibacterial agents. We interpret the resulting solution of the diffusion's equation to model charged aggregations. From here we pass to calculate electric forces that enter inside an Monte Carlo ab initio algorithm targeting to calculate the net displacement of a population of bacteria.The resulting bacteria displacements have turned out to be dependent on the Bessel function's order.",
"author_names": [
"Huber Nieto-Chaupis"
],
"corpus_id": 53278434,
"doc_id": "53278434",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Monte Carlo Simulation of Ab Initio NanoCommunications From Coulomb like Electric Forces in Bacteria Populations Chemotaxis",
"venue": "2018 IEEE XXV International Conference on Electronics, Electrical Engineering and Computing (INTERCON)",
"year": 2018
},
{
"abstract": "Cell sorting is a fundamental process that is involved in early embryo development, tumerogenesis and morphogenesis. The sorting of heterotypic cell populations is produced by a variety of inter cellular actions, e.g. differential adhesion and motility. We recently developed a software system that simulates chemotaxis based cell aggregation in 2D. The model implemented within the system includes a variety of physiological cell behaviors, such as chemical diffusion/detection, motility, proliferation, adhesion and life cycle stages. In this paper we extend the model to simulate heterotypic cell sorting. This paper provides an overview of the chemotaxis based aggregation model and describes the parameters and processes utilized to simulate the sorting of two different cell populations based on chemotactic interactions.",
"author_names": [
"Manolya Eyiyurekli",
"Peter I Lelkes",
"D E Breent"
],
"corpus_id": 14227779,
"doc_id": "14227779",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Simulation of chemotaxis based sorting of heterotypic cell populations",
"venue": "2007 IEEE/NIH Life Science Systems and Applications Workshop",
"year": 2007
},
{
"abstract": "Chemotaxis is the phenomenom in which a population of cells rearranges its structure according to the behaviour of some chemical present in the environment. In this work, we consider a kinetic description of the collective motion of bacteria, incorporating the ability of cells to response to spatial and temporal variation of the gradient of the chemical. In the presence of nutriants, it has been experimentally observed the formation of concentration waves of bacteria [4] A parabolic scaling of the kinetic model allows to recover this dynamics. Then a particular attention has been given to the interactions between different species. In a hyperbolic scaling, a macroscopic model of aggregation type is derived. Blow up of regular solutions for this system is well known and a carefull analysis of measure solutions, in the sense of duality, has been obtained in one dimension [2] Numerical simulations are challenging since it implies the treatment of singular solutions including possible Dirac deltas in order to recover the dynamics of aggregates [3] This study has been recently extended in dimension greater than one [1] thanks to the notion of the Filippov flow for transport equations with singular velocity field.",
"author_names": [
"Nicolas Vauchelet"
],
"corpus_id": 212613241,
"doc_id": "212613241",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "MATHEMATICAL DESCRIPTION OF BACTERIAL MOTION BY CHEMOTAXIS AGGREGATION AND WAVES OF CONCENTRATION",
"venue": "",
"year": 2015
},
{
"abstract": "The ability to navigate in chemical gradients, called chemotaxis, is crucial for the survival of microorganisms. It allows them to find food and to escape from toxins. Many microorganisms can produce the chemicals to which they respond themselves and use chemotaxis for signaling, which can be seen as a basic form of communication, allowing ensembles of microorganisms to coordinate their behavior, for example, during embryogenesis, biofilm formation, or cellular aggregation. For example, Dictyostelium cells use signaling as a survival strategy: when starving, they produce certain chemicals toward which other cells show taxis. This leads to aggregation of the cells resulting in a multicellular aggregate that can sustain long starvation periods. Remarkably, the past decade has led to the development of synthetic microswimmers, which can self propel through a solvent, analogously to bacteria and other microorganisms. The mechanism underlying the self propulsion of synthetic microswimmers like camphor boats, droplet swimmers, and in particular autophoretic Janus colloids involves the production of certain chemicals. As we will discuss in this Account, the same chemicals (phoretic fields) involved in the self propulsion of a (Janus) microswimmer also act on other ones and bias their swimming direction toward (or away from) the producing microswimmer. Synthetic microswimmers therefore provide a synthetic analogue to motile microorganisms interacting by taxis toward (or away from) self produced chemical fields. In this Account, we review recent progress in the theoretical description of synthetic chemotaxis mainly based on simulations and field theoretical descriptions. We will begin with single motile particles leaving chemical trails behind with which they interact themselves, leading to effects like self trapping or self avoidance. Besides these self interactions, in ensembles of synthetic motile particles each particle also responds to the chemicals produced by other particles, inducing chemical (or phoretic) cross interactions. When these interactions are attractive, they commonly lead to clusters, even at low particle density. These clusters may either proceed toward macrophase separation, resembling Dictyostelium aggregation, or, as shown very recently, lead to dynamic clusters of self limited size (dynamic clustering) as seen in experiments in autophoretic Janus colloids. Besides the classical case where chemical interactions are attractive, this Account discusses, as its main focus, repulsive chemical interactions, which can create a new and less known avenue to pattern formation in active systems leading to a variety of pattern, including clusters which are surrounded by shells of chemicals, traveling waves and more complex continuously reshaping patterns. In all these cases \"synthetic signalling\" can crucially determine the collective behavior of synthetic microswimmer ensembles and can be used as a design principle to create patterns in motile active particles.",
"author_names": [
"Benno Liebchen",
"Hartmut Lowen"
],
"corpus_id": 206384837,
"doc_id": "206384837",
"n_citations": 43,
"n_key_citations": 0,
"score": 0,
"title": "Synthetic Chemotaxis and Collective Behavior in Active Matter.",
"venue": "Accounts of chemical research",
"year": 2018
},
{
"abstract": "Complex bioconvection patterns have been studied analytically, experimentally, and numerically previously only for a flat free surface of a suspension of chemotaxis bacteria in a shallow/deep chamber. In this paper, we have considered a two dimensional chemotaxis diffusion convection system with a deformed free surface. The influence of aggregation of chemotactic cells on the deformed free surface of a shallow chamber is studied analytically. The aim of this paper is to investigate the nature of the instability in the chemotaxis diffusion convection system. We performed a detailed linear stability analysis of a steady state cell and oxygen concentration distribution. The system becomes dominated by nonlinear convection terms beyond a critical Rayleigh number Rat, which also depends on the critical wavenumber k as well as the other parameters. We have investigated that how the critical Rayleigh number in this system varies with three different sets of parameters. A weakly nonlinear analysis is carried out as well to determine the relative stability of the pattern formation at the onset of instability. A reactance between rolls, squares, hexagons, and mixed mode pattern is investigated in detail. Further research should link the weakly nonlinear analysis with the bifurcation analysis. Some important direct numerical simulation results have been presented in the support of linear stability analysis. Comparison of the analytical steady state solution shows good agreement with the numerical result.",
"author_names": [
"Symphony Chakraborty",
"Filip Ivancic",
"Maxim A Solovchuk",
"Tony W H Sheu"
],
"corpus_id": 125425189,
"doc_id": "125425189",
"n_citations": 5,
"n_key_citations": 1,
"score": 0,
"title": "Stability and dynamics of a chemotaxis system with deformed free surface in a shallow chamber",
"venue": "",
"year": 2018
},
{
"abstract": "Abstract In this paper, the chemotaxis partial differential equations models which describe the movement by one community in reaction to one chemical or biological signal are given and solved numerically on surfaces. The models and the numerical method concerned are in terms of a generic form of chemotaxis models. We develop a new semi implicit finite element scheme based on the gradient and Laplacian recoveries to linearize the equations. Meanwhile, we modify the proposed semi implicit scheme as a characteristic form and present a novel strategy for the discretization of characteristic derivative on surface. The lumped mass modification is employed for positivity preservation. And the related analysis results are provided. We investigate the accuracy and convergence of the proposed method by numerical tests. And the simulations of blowing up solution, pattern formulations and aggregations of bacteria demonstrate the applicability of the proposed methods.",
"author_names": [
"Xufeng Xiao",
"Xinlong Feng",
"Yinnian He"
],
"corpus_id": 126677986,
"doc_id": "126677986",
"n_citations": 12,
"n_key_citations": 0,
"score": 0,
"title": "Numerical simulations for the chemotaxis models on surfaces via a novel characteristic finite element method",
"venue": "Comput. Math. Appl.",
"year": 2019
},
{
"abstract": "We have developed a software system that simulates chemotaxis based cell aggregation in 2D. The model implemented within the system consists of such cell behaviors as chemical diffusion/detection, motility, proliferation, adhesion and life cycle stages. Each virtual cell detects the state of the environment, and responds to the environment based on a pre defined \"program\" and its own internal state. Cells are discrete units that are located on a grid, exist in discrete states (e.g. active or dying) and perform discrete tasks (e.g. divide and attach) but they also contain and are affected by continuous quantities (e.g. chemoattractant concentrations, gradients, age and velocities) This paper provides an overview of our chemotaxis based aggregation model and details the algorithms required to perform chemotaxis based cell aggregation simulation. A number of biological studies are being conducted with the system. They include fine tuning the model parameters to reproduce in vitro PC12 cell aggregation experiments and parametric studies that demonstrate the effect that the model's components have on cell aggregation dynamics.",
"author_names": [
"Manolya Eyiyurekli",
"Peter I Lelkes",
"David E Breen"
],
"corpus_id": 5990687,
"doc_id": "5990687",
"n_citations": 14,
"n_key_citations": 0,
"score": 0,
"title": "A Computational System for Investigating Chemotaxis Based Cell Aggregation",
"venue": "ECAL",
"year": 2007
},
{
"abstract": "We present a new algorithm based on a Cartesian mesh for the numerical approximation of kinetic models for chemosensitive movements set in an arbitrary geometry. We investigate the influence of the geometry on the collective behavior of bacteria described by a kinetic equation interacting with nutrients and chemoattractants. Numerical simulations are performed to verify accuracy and stability of the scheme and its ability to exhibit aggregation of cells and wave propagations. Finally, some comparisons with experiments show the robustness and accuracy of such kinetic models.",
"author_names": [
"Francis Filbet",
"Chang Yang"
],
"corpus_id": 15653923,
"doc_id": "15653923",
"n_citations": 16,
"n_key_citations": 0,
"score": 0,
"title": "Numerical Simulations of Kinetic Models for Chemotaxis",
"venue": "SIAM J. Sci. Comput.",
"year": 2014
},
{
"abstract": "Understanding the collective motion of self propelling organisms in confined geometries, such as that of narrow channels, is of great theoretical and practical importance. By means of numerical simulations we study the motion of model bacteria in 2D channels under different flow conditions: fluid at rest, steady and unsteady flow. We find aggregation of bacteria near channel walls and, in the presence of external flow, also upstream swimming, which turns out to be a very robust result. Detailed analysis of bacterial velocity and orientation fields allows us to quantify the phenomenon by varying cell density, channel width and fluid velocity. The tumbling mechanism turns out to have strong influence on velocity profiles and particle flow, resulting in a net upstream flow in the case of non tumbling organisms. Finally we demonstrate that upstream flow can be enhanced by a suitable choice of an unsteady flow pattern.",
"author_names": [
"Andrea Costanzo",
"Roberto Di Leonardo",
"Giancarlo Ruocco",
"Luca Angelani"
],
"corpus_id": 42436747,
"doc_id": "42436747",
"n_citations": 56,
"n_key_citations": 1,
"score": 0,
"title": "Transport of self propelling bacteria in micro channel flow.",
"venue": "Journal of physics. Condensed matter an Institute of Physics journal",
"year": 2012
}
] |
Customer Relationship Management in manufacturing | [
{
"abstract": "Customer Relationship management (CRM) oriented knowledge management focus on customer knowledge more valuable to the company. The integration of customer relationship management and knowledge management concepts on process level are beneficial for both management approaches. Therefore, the aim of this paper is to examine and elaborate the linking between knowledge management process and customer relationship management to create a customer knowledge management (CKM) model. We need a CKM outputs impacting on business innovation. Under the objective, we studied literatures about CKM. We results are CKM process, CKM competence, CKM outputs. We have 12 ways of innovation competence and their corresponding CKM outputs. The implication of Knowledge innovation of Taiwan Semiconductor Manufacturing Companys experience is presented.",
"author_names": [
"Ming Li"
],
"corpus_id": 167571137,
"doc_id": "167571137",
"n_citations": 4,
"n_key_citations": 1,
"score": 0,
"title": "Customer Relationship management and knowledge Management enhancing on innovation Competence: Case Study",
"venue": "",
"year": 2014
},
{
"abstract": "With the rapid change of business competitive environment, enterprise resource integration and innovative issues of business operation have gradually become the most important issues for businesses. Furthermore, many enterprises have implemented novel information technology and developing the innovative e business applications systems such as enterprise resource planning (ERP) customer relationship management (CRM) knowledge management (KM) and supply chain management (SCM) to enhance their competitive advantages. CRM systems can help organizations to gain the potential new customers, promote the existing customers' purchase, maintain good relationship with customers as well as to enhance the customer value, thus can improve the enterprise images. Moreover, the development and applications of CRM systems have also been considered as important issues for researchers and practitioners in recent years. For Taiwan's industry, it has been gradually transferred from manufacturing oriented to a service oriented. Thus, the service industry has higher percentage in the GDP and in which the distribution service industry is the biggest one and be a core industry in the whole of service industry. The main purpose of this study is to explore the factors affecting the acceptance and use of CRM systems. Furthermore, the proposed research model was built on the basis of unified theory of acceptance and use of technology (UTAUT) and task technology fit (TTF) framework as well as technological and managerial theories. The implications of findings for practice will be discussed.",
"author_names": [
"Jungchi Pai",
"Fu-Ming Tu"
],
"corpus_id": 11283025,
"doc_id": "11283025",
"n_citations": 99,
"n_key_citations": 5,
"score": 0,
"title": "The acceptance and use of customer relationship management (CRM) systems: An empirical study of distribution service industry in Taiwan",
"venue": "Expert Syst. Appl.",
"year": 2011
},
{
"abstract": "Purpose Customer relationship management (CRM) projects have a low success rate, which can be solved by better measurement of CRM process. The purpose of this paper is to define the CRM processes within a company and propose a tool for CRM measurement.Design/methodology/approach An empirical study is conducted in industrial organizations in Turkey. The research is designed according to scale development literature. The responses from various industries (manufacturing, information technologies, tourism, service, retail, finance, logistics) were collected. Using exploratory factor analysis, 167 valid responses are analyzed.Findings The paper provides a general understanding of CRM processes in customer oriented perspective and proposes a measurement tool that addresses seven main processes which are: targeting management, customer information management, production/service customization, expansion management, referrals management, termination management and win back.Practical implications The result.",
"author_names": [
"Basar Oztaysi",
"Selime Sezgin",
"Ahmet Fahri Ozok"
],
"corpus_id": 8139259,
"doc_id": "8139259",
"n_citations": 75,
"n_key_citations": 5,
"score": 0,
"title": "A Measurement Tool for Customer Relationship Management Processes",
"venue": "Ind. Manag. Data Syst.",
"year": 2011
},
{
"abstract": "The primary purpose of this study is to understand how customer value is affected by total quality management practices and marketing management policies of an organization. Total quality management is a complete managerial approach that if practiced provides ground for the identification of marketing strategies and processes. This management philosophy leads organizations towards gaining of competitive advantage through the proper enforcement of strategically fit and aligned strategies. However, customer relationship management plays key role in synergic effect of total quality management practices and marketing management on customer's value. This research study is primarily quantitative in nature. Data has been collected from different national and multinational companies of manufacturing sector in Pakistan and the sample size in total is that of 114. The data collection instrument was developed on the basis of literature and was found to be statistically reliable where Cronbach's alpha for all concepts under study was at least 0.800. In order address the objectives of this study and test the hypothesis of relationships between variables, Pearson correlation test was applied on the data set. As a result of analysis, strongly positive correlation was found between total quality management, marketing management, customer relationship management and customer's value. Hence, it would be fair enough to conclude total quality management practices provides basic ground to identify marketing management Policies, strategies and practices.\"",
"author_names": [
"Dr Syed Sohaib Zubair",
"Umair Mehmood",
"A F Salam"
],
"corpus_id": 168542893,
"doc_id": "168542893",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Synergic Relationship between Total Quality Management and Marketing Management in Creating Customer's Value",
"venue": "",
"year": 2015
},
{
"abstract": "This paper investigates the relationship between customer relationship management (CRM) in supply chain management (SCM) and its power to enhance product quality and customer satisfaction of Malaysian manufacturing companies. Senior production managers were interviewed utilizing a structured survey instrument to gauge their perceptions of CRM, product quality performance and customer satisfaction. Inferential statistical analyses were conducted by utilizing data from 250 companies. Associations between CRM dimensions, product quality and customer satisfaction were analyzed through statistical methods such as cluster analysis, Friedman's test and structural equation modelling (SEM) The findings of cluster analysis and Friedman's test indicate that 'High customer satisfaction achievers' possess higher levels of CRM implementations and give priorities to dimensions such as 'Measures evaluates customer satisfaction, 'Evaluates relationship with customers continuously' and 'Provides Follow up and after sale services than 'low customer satisfaction achievers' The result of the partially mediated SEM model reveals that CRM exhibits direct impact on customer satisfaction and also indirect effect mediated by product quality. Overall, findings of the study provide a striking demonstration of the importance of customer relationship management in SCM to enhance product quality and customer satisfaction in Malaysian manufacturing companies.",
"author_names": [
"Arawati Agus",
"Za'faran Hassan"
],
"corpus_id": 15647130,
"doc_id": "15647130",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "The Power of Customer Relationship Management in Enhancing Product Quality and Customer Satisfaction",
"venue": "",
"year": null
},
{
"abstract": "Total quality management (TQM) practises are well known approaches that most of the overseas company used. But in Malaysian company, this approach is not so often used. Other than that, not many researchers do the research about the effect of TQM practises on operational performance. So the aims of this research are to identify the levels of TQM practises (leadership, customer focus, management of people, process improvement, strategic planning and use of information and analysis) for operational performance and to determine the effect of TQM practises on operational performance. The indicators of operational performance are productivity, quality and waste level. The collected data was analysed by using descriptive statistic, reliability, normality, Pearson Correlation, single mean t test and regression analysis. As a result, only strategic planning and process improvement practises positively contribute to operational performance. For future researcher, they should do more research about operational performance like increase the numbers of indicators for operational performance. Therefore, they can give more comprehensive understanding to colleagues and students about operational performance.",
"author_names": [
"Buniamin Nur Anis"
],
"corpus_id": 113472287,
"doc_id": "113472287",
"n_citations": 3,
"n_key_citations": 0,
"score": 1,
"title": "Relationship between total quality management (TQM) practises and operational performance in manufacturing company",
"venue": "",
"year": 2016
},
{
"abstract": "Networked manufacturing is an advanced manufacturing technology, and efficient customer relationship management is critical for networked manufacturing's resource allocation and scheduling. Evaluation of customer relationship management's performance under networked manufacturing and effective optimization measures are preconditions for improving on CRM's performance. Development process's quality, operational process's quality, customer relationship's quality and emergency ability are critical factors of CRM's performance under networked manufacturing. Evaluating CRM's performance should build index system based on these four factors and make grey correlative analysis combined with analytic hierarchy process. The performance evaluation way proposed is feasible and effective, and combines the advantage of quantitative analysis and qualitative analysis.",
"author_names": [
"Jinzhao An"
],
"corpus_id": 26434509,
"doc_id": "26434509",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Evaluation of Customer Relationship Management's Performance under Networked Manufacturing",
"venue": "",
"year": 2009
},
{
"abstract": "Now a days Data Mining tools for Customer Relationship Management are used by several industries includin g banking, finance, retail, insurance, telecommunications, dat abase marketing, sales forecasting, call behavior analys is and churning management in tele communications, forecasting of demand for utilities such as energy and water, simulation of c hemical and other process reactions finding critical factors in discrete manufacturing, CPU usage, and forecasting, etc. D ata mining is often referred to as \"analytical intelligence\" Dat a Mining help Organizations better understand their business, be able to better serve their customers and increase the effectiv eness of the organization in the long run. This article provides an overview of the concept of Data mining and Customer Relationship Management.",
"author_names": [
"V Thanuja",
"B Venkateswarlu",
"G S G N Anjaneyulu"
],
"corpus_id": 167997974,
"doc_id": "167997974",
"n_citations": 13,
"n_key_citations": 0,
"score": 0,
"title": "Applications of Data Mining in Customer Relationship Management",
"venue": "",
"year": 2011
},
{
"abstract": "The article focuses on technology and tools such as enterprise resource planning (ERP) the customer analysis of algorithms, data warehousing, OLAP, CRM modules, combining with ideas of customer relationship management, to put forward the model and program of manufacturing enterprise customer relationship management application, which is the implementation of enterprise CRM, improve the relevance and effectiveness of services, and provide an effective solution.",
"author_names": [
"Longyi Li",
"Yansheng Zhang"
],
"corpus_id": 9809490,
"doc_id": "9809490",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Notice of RetractionStudy on Customer Relationship Management System of Manufacturing Enterprises Based on ERP",
"venue": "2009 International Conference on Management and Service Science",
"year": 2009
},
{
"abstract": "Customer Relationship Management Systems have been employed by large organisations for a number of years, but with the availability of inexpensive hardware and software and easy access to the Internet, Small and Medium sized Enterprises (SMEs) are now starting to adopt CRM systems. This paper describes a study of the factors influencing CRM adoption in 126 SMEs in the retail, manufacturing and service sectors in Southern California. The factors considered were management characteristics, the firm's characteristics, employee characteristics, and IT resources. The results indicate that management's innovativeness affects the firm's perception of CRM systems, but age, education and gender do not. The decision to implement a CRM system is influenced by management's perception of CRM, employee involvement, the firm's size, its perceived market position, but not the industry sector. However, the number and types of CRM features implemented are affected by management's perception of CRM, employee involvement, the firm's size, the industry sector, but not its perceived market position.",
"author_names": [
"ThuyUyen H Nguyen",
"Michael Newby",
"Teresa S Waring"
],
"corpus_id": 10458194,
"doc_id": "10458194",
"n_citations": 8,
"n_key_citations": 0,
"score": 0,
"title": "Understanding Customer Relationship Management (CRM) Technology Adoption In SMEs: An Empirical Study In The USA",
"venue": "UKAIS",
"year": 2012
}
] |
Reliability prediction of semiconductor devices using modified physics of failure approach | [
{
"abstract": "Traditional approaches like MIL HDBK, Telcordia, and PRISM etc. have limitation in accurately predicting the reliability due to advancement in technology, process, materials etc. As predicting the reliability is the major concern in the field of electronics, physics of failure approach gained considerable importance as it involves investigating the root cause which further helps in reliability growth by redesigning the structure, changing the parameters at manufacturer level and modifying the items at circuit level. On the other hand, probability and statistics methods provide quantitative data with reliability indices from testing by experimentation and by simulations. In this paper, qualitative data from PoF approach and quantitative data from the statistical analysis is combined to form a modified physics of failure approach. This methodology overcomes some of the challenges faced by PoF approach as it involves detailed analysis of stress factors, data modeling and prediction. A decision support system is added to this approach to choose the best option from different failure data models, failure mechanisms, failure criteria and other factors.",
"author_names": [
"Adithya Thaduri",
"Ajit Kumar Verma",
"Gopika Vinod",
"Rajesh Gopinath",
"Uday Kumar"
],
"corpus_id": 3260874,
"doc_id": "3260874",
"n_citations": 12,
"n_key_citations": 0,
"score": 1,
"title": "Reliability prediction of semiconductor devices using modified physics of failure approach",
"venue": "Int. J. Syst. Assur. Eng. Manag.",
"year": 2013
},
{
"abstract": "Traditional reliability prediction methods are being confounded by current and near future semiconductor technologies, as gate feature sizes shrink below 100 nanometers (nm) causing the emergence of atomic level failure mechanisms and early wearout. These devices and their failure characteristics are rapidly changing as the semiconductor industry aggressively pursues scaling in a highly competitive marketplace. The Physics of Failure (PoF) approach to reliability has advantages for assessing these technologies. Industry groups are adapting PoF research results for use in predicting reliability for these technologies. This paper describes industry collaborative efforts in developing new reliability prediction approaches to meet future industry challenges.",
"author_names": [
"Lori E Bechtold"
],
"corpus_id": 20384899,
"doc_id": "20384899",
"n_citations": 8,
"n_key_citations": 0,
"score": 0,
"title": "Industry consensus approach to physics of failure in reliability prediction",
"venue": "2010 Proceedings Annual Reliability and Maintainability Symposium (RAMS)",
"year": 2010
},
{
"abstract": "An original reliability prediction procedure is presented. The physics of failure accounts for the failure mechanisms involved (a lognormal distribution was presumed) the interactions (synergies) between the technology factors depending on the manufacturing techniques are considered. The basis of this methodology (called SYRP=synergetic reliability prediction) is the assessment of failure risk coefficients (FRC) based on fuzzy logic, for the potential failure mechanisms induced at each manufacturing step. These FRC are corrected at the subsequent steps by considering the synergy of the manufacturing factors, At the end of the manufacturing process, final FRC are obtained for each potential failure mechanism; the parameters of the lognormal distribution are calculated with a simple algorithm. Experimental results for four lots of the same type of semiconductor devices, each lot being manufactured with a slightly different technology, were obtained. SYRP forecasts for these four lots agree well with accelerated life test results. This is a fairly good result, because SYRP was used early, at the design phase.",
"author_names": [
"Marius Bazu"
],
"corpus_id": 123544782,
"doc_id": "123544782",
"n_citations": 23,
"n_key_citations": 0,
"score": 0,
"title": "A combined fuzzy logic and physics of failure approach to reliability prediction",
"venue": "",
"year": 1995
},
{
"abstract": "Modern electronics typically consist of microprocessors and other complex integrated circuits (ICs) such as FPGAs, ADCs, and memory. They are susceptible to electrical, mechanical and thermal modes of failure like other components on a printed circuit board, but due to their materials, complexity and roles within a circuit, accurately predicting a failure rate has become difficult, if not impossible. Development of these critical components has conformed to Moore's Law, where the number of transistors on a die doubles approximately every two years. This trend has been successfully followed over the last four decades through reduction in transistor sizes creating faster, smaller ICs with greatly reduced power dissipation. Although this is great news for developers and users of high performance equipment, including consumer products and analytical instrumentation, a crucial, yet underlying reliability risk has emerged. Semiconductor failure mechanisms, which are far worse at these minute feature sizes (tens of nanometers) result in higher failure rates, shorter device lifetimes and unanticipated early device wearout. This is of special concern to users whose requirements include long service lifetimes and rugged environmental conditions, such as aerospace, defense, and other high performance (ADHP) industries. To that end, the Aerospace Vehicle Systems Institute (AVSI) has conducted research in this area, and DfR Solutions has performed much of the work as a contractor to AVSI. Physics of Failure (PoF) knowledge and an accurate mathematical approach which utilizes semiconductor formulae, industry accepted failure mechanism models, and device functionality can access reliability of those integrated circuits vital to system stability. Currently, four semiconductor failure mechanisms that exist in silicon based ICs are analyzed: Electromigration (EM) Time Dependent Dielectric Breakdown (TDDB) Hot Carrier Injection (HCI) and Negative Bias Temperature Instability (NBTI) Mitigation of these inherent failure mechanisms, including those considered wearout, is possible only when reliability can be quantified. Algorithms have been folded into a software application not only to calculate a failure rate, but also to produce confidence intervals and lifetime curves, using both steady state and wearout failure rates, for the IC under analysis. The algorithms have been statistically verified through testing and employ data and formulae from semiconductor materials (including technology node parameters) circuit fundamentals, transistor behavior, circuit design and fabrication processes. Initial development has yielded a user friendly software module with the ability to address siliconbased integrated circuits of the 0.35m, 0.25m, 0.18m, 0.13m and 90nm technology nodes. INTRODUCTION In the ADHP industries, there is considerable interest in assessing the long term reliability of electronics whose anticipated lifetimes extend beyond those of consumer \"throw away\" electronics. Because complex integrated circuits within their designs may face wearout or even failure within the period of useful life, it is necessary to investigate the effects of use and environmental conditions on these components. The main concern is that submicron process technologies drive device wearout into the regions of useful life well before wearout was initially anticipated to occur. The continuous scaling down of semiconductor feature sizes raises challenges in electronic circuit reliability prediction. Smaller and faster circuits cause higher current densities, lower voltage tolerances and higher electric fields, which make the devices more vulnerable to early failure. Emerging new generations of electronic devices require improved tools for reliability prediction in order to investigate new manifestations of existing failure mechanisms, such as NBTI, EM, HCI, and TDDB. Working with AVSI, DfR Solutions has developed an integrated circuit (IC) reliability calculator using a multiple failure mechanism approach. This approach successfully models the simultaneous degradation behaviors of multiple failure mechanisms on integrated circuit devices. The multiple mechanism model extrapolates independent acceleration factors for each semiconductor mechanism of concern based on the transistor stress states within each distinct functional group. Integrated circuit lifetime is calculated from semiconductor materials and technology node, IC complexity, and operating conditions. A major input to the tool is integrated circuit complexity. This characteristic has been approached by using specific functionality cells called functional groups. The current set of functional groups covers memory based devices and analog todigital conversion circuitry. Technology node process parameters, functional groups and their functionality, and field/test operating conditions are used to perform the calculations. Prior work verified the statistical assessment of the algorithms for aerospace electronic systems and confirmed that no single semiconductor failure mechanism dominates failures in the field. Two physics of failure approaches are used within the tool to determine each of four semiconductor failure mechanisms' contribution to the overall device failure rate. The tool calculates a failure rate and also produces confidence intervals and a lifetime curve, using both steady state and wearout failure rates, for the part under analysis. Reliability prediction simulations are the most powerful tools developed over the years to cope with these challenging demands. Simulations may provide a wide range of predictions, starting from the lower level treatment of physics of failure (PoF) mechanisms up to high level simulations of entire devices [1, 2] As with all simulation problems, primary questions need to be answered, such as: \"How accurate are the simulation results in comparison to in service behavior?\" and \"What is the confidence level achieved by the simulations?\" Thus the validation and calibration of the simulation tools becomes a most critical task. Reliability data generated from field failures best represents the electronic circuit reliability in the context of the target system/application. Field failure rates represent competing failure mechanisms' effects and include actual stresses, in contrast to standard industry accelerated life tests. In this paper, the failure rates of recorded field data from 2002 to 2009 were determined for various device process technologies and feature sizes (or \"technology nodes\" Theses failure rates are used to verify the PoF models and a competing failure approach, as implemented in the software. Comparison of the actual and simulated failure rates shows a strong correlation. Furthermore, comparing the field failure rates with those obtained from the standard industry High Temperature Operating Life (HTOL) Test reveals the inadequacy of the HTOL to predict integrated circuit (IC) failure rates. The validation process and its data sources are illustrated in Figure 1.",
"author_names": [
"Edward J Wyrwas",
"College Park",
"Lloyd W Condra",
"Avshalom Hava"
],
"corpus_id": 15650293,
"doc_id": "15650293",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Accurate Quantitative Physics of Failure Approach to Integrated Circuit Reliability",
"venue": "",
"year": 2011
},
{
"abstract": "Conventionally, reliability prediction of electronic components is carried out using standard handbooks such as MIL STD 217 plus, Telcordia, etc. But these methods fail to provide a realistic estimate of reliability for upcoming technologies. Currently, electronic reliability prediction is moving towards applying the Physics of Failure approach which considers information on process, technology, fabrication techniques, materials used, etc. Industries employ different technologies like CMOS, BJT and BICMOS for various applications. The possibility of chance of failure at interdependencies of materials, processes, and characteristics under operating conditions is the major concern which affects the performance of the devices. They are characterized by several failure mechanisms at various stages such as wafer level, interconnection, etc. For this, the dominant failure mechanisms and stress parameters needs to be identified. Optocouplers are used in input protection of several instrumentation systems providing safety under over stress conditions. Hence, there is a need to study the reliability and safety aspects of optocouplers. Design of experiments is an efficient and prominent methodology for finding the reliability of the item, as the experiment provides a proof for the hypothesis under consideration. One of the important techniques involved is Taguchi method which is employed for finding the prominent failure mechanisms in semiconductor devices. By physics of failure approach, the factors that are affecting the performance on both environmental and electrical parameters with stress levels for optocouplers are identified. By constructing a 2 stage Taguchi array with these parameters where output parameters decides the effect of top two dominant failure mechanisms and their extent of chance of failure can be predicted. This analysis helps us in making the appropriate modifications considering both the failure mechanisms for the reliability growth of these devices. This paper highlights the application of design of experiments for finding the dominant failure mechanisms towards using physics of failure approach in electronic reliability prediction of optocouplers for application of instrumentation.",
"author_names": [
"Adithya Thaduri",
"Ajit Kumar Verma",
"Gopika Vinod",
"Mr Rajesh",
"Uday Kumar"
],
"corpus_id": 62749400,
"doc_id": "62749400",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "TWO STAGE DESIGN OF EXPERIMENTS APPROACH FOR PREDICTION OF RELIABILITY OF OPTOCOUPLERS",
"venue": "",
"year": 2012
},
{
"abstract": "This paper presents a probabilistic approach based reliability prediction model of semiconductor light emitting devices. Using this model with given initial light emitting performance and degradation behavior otherwise determined by experiment, the reliability function of the devices is obtained, and the results correlate well with experimental results. (Modeling the initial light emitting performance and the degradation behavior is still an on going effort and is not included in this paper. Eventually, this model will include both parts of the modeling to provide complete analytical results of reliability prediction. This study is a step to develop a complete physics of failure based reliability prediction methodology for semiconductor light emitting devices. It provides an approach and proves the feasibility of determining a reliability function based on fundamental parameters of device performance.",
"author_names": [
"Jingsong Xie",
"Michael G Pecht"
],
"corpus_id": 17646194,
"doc_id": "17646194",
"n_citations": 24,
"n_key_citations": 0,
"score": 0,
"title": "Reliability prediction modeling of semiconductor light emitting device",
"venue": "",
"year": 2003
},
{
"abstract": "Conventionally, reliability prediction of electronic components is carried out using standard handbooks such as MIL STD 217plus, Telecordia, etc. But these methods fail to provide a realistic estimate of reliability for upcoming technologies. Currently, electronic reliability prediction is moving towards applying the Physics of Failure approach which considers information on process, technology, fabrication techniques, materials used, etc. Industries employ different technologies like CMOS, BJT and BICMOS for various applications. The possibility of chance of failure at interdependencies of materials, processes, and characteristics under operating conditions is the major concern which affects the performance of the devices. They are characterized by several failure mechanisms at various stages such as wafer level, interconnection, etc. For this, the dominant failure mechanisms and stress parameters needs to be identified. Optocouplers are used in input protection of several instrumentation systems providing safety under over stress conditions. Hence, there is a need to study the reliability and safety aspects of optocouplers. Design of experiments is an efficient and prominent methodology for finding the reliability of the item, as the experiment provides a proof for the hypothesis under consideration. One of the important techniques involved is Tagauchi method which employs for finding the prominent failure mechanisms in semiconductor devices. By physics of failure approach, the factors that are affecting the performance on both environmental and electrical parameters with stress levels for optocouplers are identified. By constructing a 2 stage tagauchi array with these parameters where output parameters decides the effect of top two dominant failure mechanisms and their extent of chance of failure can be predicted. This analysis helps us in making the appropriate modifications considering both the failure mechanisms for the reliability growth of these devices. This paper highlights the application of design of experiments for finding the dominant failure mechanisms towards using physics of failure approach in electronic reliability prediction of optocouplers for application of instrumentation.",
"author_names": [
"Adithya Thaduri",
"Ajit Kumar Verma",
"Gopika Vinod",
"Rajesh Gopalan"
],
"corpus_id": 24490383,
"doc_id": "24490383",
"n_citations": 14,
"n_key_citations": 0,
"score": 0,
"title": "Reliability prediction of optocouplers for the safety of digital instrumentation",
"venue": "2011 IEEE International Conference on Quality and Reliability",
"year": 2011
},
{
"abstract": "Abstract Power electronics uses semiconductor technology to convert and control electrical power. Demands for efficient energy management, conversion and conservation, and the increasing take up of electronics in transport systems has resulted in tremendous growth in the use of power electronics devices such as Insulated Gate Bipolar Transistors (IGBT's) The packaging of power electronics devices involves a number of challenges for the design engineer in terms of reliability. For example, IGBT modules will contain a number of semiconductor dies within a small footprint bonded to substrates with aluminum wires and wide area solder joints. To a great extent, the reliability of the package will depend on the thermo mechanical behavior of these materials. This paper details a physics of failure approach to reliability predictions of IGBT modules. It also illustrates the need for a probabilistic approach to reliability predictions that include the effects of design variations. Also discussed are technologies for predicting the remaining life of the package when subjected to qualification stresses or in service stresses using prognostics methods.",
"author_names": [
"Hua Lu",
"Chris Bailey",
"Chunyan Yin"
],
"corpus_id": 15939674,
"doc_id": "15939674",
"n_citations": 146,
"n_key_citations": 3,
"score": 0,
"title": "Design for reliability of power electronics modules",
"venue": "Microelectron. Reliab.",
"year": 2009
},
{
"abstract": "A method for reliability prediction, called SYRP (synergetic reliability prediction) is presented, based on a combined fuzzy logic physics of failure approach. SYRP is used for a semiconductor device (thermal sensors) and the estimations, compared with experimental results, prove to be accurate enough. Also, the problems to be solved for using this method for MEMS are presented. The specific case of a MEMS Fabry Perot interferometer is analyzed and the failure rate estimations are discussed. The method seems to be particularly useful for the reliability analysis made by virtual prototyping",
"author_names": [
"Marius Bazu",
"Catalin Tibeica",
"Lucian Galateanu",
"Virgil Emil Ilian"
],
"corpus_id": 15875263,
"doc_id": "15875263",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Fuzzy Logic Reliability Predictions in Microtechnologies",
"venue": "International Conference on Computational Intelligence for Modelling, Control and Automation and International Conference on Intelligent Agents, Web Technologies and Internet Commerce (CIMCA IAWTIC'06)",
"year": 2005
},
{
"abstract": "Because of increased manufacturing competitiveness, new methods for reliability estimation are being developed. Intelligent manufacturing relies upon accurate component and product reliability estimates for determining warranty costs, as well as optimal maintenance, inspection, and replacement schedules. Accelerated life testing is one approach that is used for shortening the life of products or components or hastening their performance degradation with the purpose of obtaining data that may be used to predict device life or performance under normal operating conditions. The proportional hazards (PH) model is a non parametric multiple regression approach for reliability estimation, in which a baseline hazard function is modified multiplicatively by covariates (i.e. applied stresses) While the PH model is a distribution free approach, specific assumptions need to be made about the time behavior of the hazard rates. A neural network (NN) is particularly useful in pattern recognition problems that involve capturing and learning complex underlying (but consistent) trends in the data. Neural networks are highly non linear, and in some cases are capable of producing better approximations than multiple regression. This paper reports on the comparison of PH and NN models for the analysis of time dependent dielectric breakdown data for a metal oxide semiconductor integrated circuit. In this case, the NN model results in a better fit to the data based upon minimizing the mean square error of the predictions when using failure data from an elevated temperature and voltage to predict reliability at a lower temperature and voltage.",
"author_names": [
"James T Luxhoj",
"Huan-Jyh Shyur"
],
"corpus_id": 26687762,
"doc_id": "26687762",
"n_citations": 18,
"n_key_citations": 0,
"score": 0,
"title": "Comparison of proportional hazards models and neural networks for reliability estimation",
"venue": "J. Intell. Manuf.",
"year": 1997
}
] |
Introduction to Materials Science for Engineers | [
{
"abstract": "1. Materials for Engineering. I. THE FUNDAMENTALS. 2. Atomic Bonding. 3. Crystalline Structure Perfection. 4. Crystal Defects and Noncrystalline Structure Imperfection. 5. Diffusion. 6. Mechanical Behavior. 7. Thermal Behavior. 8. Failure Analysis and Prevention. 9. Phase Diagrams Equilibrium Microstructural Development. 10. Kinetics Heat Treatment. II. THE STRUCTURAL MATERIALS. 11. Metals. 12. Ceramics and Glasses. 13. Polymers. 14. Composites. III. THE ELECTRONIC, OPTICAL AND MAGNETIC MATERIALS. 15. Electrical Behavior. 16. Optical Behavior. 17. Semiconductor Materials. 18. Magnetic Materials. IV. MATERIALS IN ENGINEERING DESIGN. 19. Environmental Degradation. 20. Materials Selection.",
"author_names": [
"James F Shackelford"
],
"corpus_id": 137215766,
"doc_id": "137215766",
"n_citations": 705,
"n_key_citations": 26,
"score": 1,
"title": "Introduction to materials science for engineers",
"venue": "",
"year": 1985
},
{
"abstract": "Foundations Of Materials Science And Engineering is writen by William Smith in English language. Release on 2009 04 09, this book has 1056 page count that contain essential information with easy reading experience. The book was publish by McGraw Hill Science/Engineering/Math, it is one of best engineering transportation book genre that gave you everything love about reading. You can find Foundations Of Materials Science And Engineering book with ISBN 0073529249.",
"author_names": [
"Joan Schweikart"
],
"corpus_id": 108670472,
"doc_id": "108670472",
"n_citations": 114,
"n_key_citations": 7,
"score": 0,
"title": "An Introduction to Materials Engineering and Science for Chemical and Materials Engineers",
"venue": "",
"year": 2004
},
{
"abstract": "Preface. Acknowledgments. 1 The Structure of Materials. 1.0 Introduction and Objectives. 1.1 Structure of Metals and Alloys. 1.2 Structure of Ceramics and Glasses. 1.3 Structure of Polymers. 1.4 Structure of Composites. 1.5 Structure of Biologics. References. Problems. 2 Thermodynamics of Condensed Phases. 2.0 Introduction and Objectives. 2.1 Thermodynamics of Metals and Alloys. 2.2 Thermodynamics of Ceramics and Glasses. 2.3 Thermodynamics of Polymers. 2.4 Thermodynamics of Composites. 2.5 Thermodynamics of Biologics. References. Problems. 3 Kinetic Processes in Materials. 3.0 Introduction and Objectives. 3.1 Kinetic Processes in Metals and Alloys. 3.2 Kinetic Processes in Ceramics and Glasses. 3.3 Kinetic Processes in Polymers. 3.4 Kinetic Processes in Composites. 3.5 Kinetic Processes in Biologics. References. Problems. 4 Transport Properties of Materials. 4.0 Introduction and Objectives. 4.1 Momentum Transport Properties of Materials. 4.2 Heat Transport Properties of Materials. 4.3 Mass Transport Properties of Materials. References. Problems. 5 Mechanics of Materials. 5.0 Introduction and Objectives. 5.1 Mechanics of Metals and Alloys. 5.2 Mechanics of Ceramics and Glasses. 5.3 Mechanics of Polymers. 5.4 Mechanics of Composites. 5.5 Mechanics of Biologics. References. Problems. 6 Electrical, Magnetic, and Optical Properties of Materials. 6.1 Electrical Properties of Materials. 6.2 Magnetic Properties of Materials. 6.3 Optical Properties of Materials. References. Problems. 7 Processing of Materials. 7.0 Introduction. 7.1 Processing of Metals and Alloys. 7.2 Processing of Ceramics and Glasses. 7.3 Processing of Polymers. 7.4 Processing of Composites. 7.5 Processing of Biologics. References. Problems. 8 Case Studies in Materials Selection. 8.0 Introduction and Objectives. 8.1 Selection of Metals for a Compressed Air Tank. 8.2 Selection of Ceramic Piping for Coal Slurries in a Coal Liquefaction Plant. 8.3 Selection of Polymers for Packaging. 8.4 Selection of a Composite for an Automotive Drive Shaft. 8.5 Selection of Materials as Tooth Coatings. References. Problems. Appendix 1: Energy Values for Single Bonds. Appendix 2: Structure of Some Common Polymers. Appendix 3: Composition of Common Alloys. Appendix 4: Surface and Interfacial Energies. Appendix 5: Thermal Conductivities of Selected Materials. Appendix 6: Diffusivities in Selected Systems. Appendix 7: Mechanical Properties of Selected Materials. Appendix 8: Electrical Conductivity of Selected Materials. Appendix 9: Refractive Index of Selected Materials. Answers to Selected Problems. Index. Sections marked with an asterisk can be omitted in an introductory course.",
"author_names": [
"Brian S Mitchell"
],
"corpus_id": 135657767,
"doc_id": "135657767",
"n_citations": 124,
"n_key_citations": 2,
"score": 0,
"title": "An introduction to materials engineering and science for chemical and materials engineers",
"venue": "",
"year": 2003
},
{
"abstract": "In the case of General Chemistry, many engineering students only take a one semester class with important topics such as kinetics and equilibrium being given limited coverage. Considerable time is spent covering materials already covered in other courses such as General Physics and Introduction to Engineering. Moreover, most GChem courses are oriented toward health science majors and lack a materials focus relevant to engineering. Taking an atoms first approach, we developed and now run a one semester course in general chemistry for engineers emphasizing relevant materials topics. Laboratory exercises integrate practical examples of materials science enriching the course for engineering students. First semester calculus and a calculus based introduction to engineering course are prerequisites, which enables teaching almost all the topics from a traditional two semester GChem course in this new course with advance topics as well. To support this course, an open access textbook in LibreText, formerly ChemWiki was developed entitled General Chemistry for Engineering Many of the topics were supported using Chemical Excelets and Materials Science Excelets, which are interactive Excel/Calc spreadsheets. The laboratory includes data analysis and interpretation, calibration, error analysis, reactions, kinetics, electrochemistry, and spectrophotometry. To acquaint the students with online collaboration typical of today's technical workplace Google Drive was used for data analysis and report preparation in the laboratory.",
"author_names": [
"Scott A Sinex",
"Joshua B Halpern",
"Scott D Johnson"
],
"corpus_id": 136289326,
"doc_id": "136289326",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "General Chemistry for Engineers in the 21st Century: A Materials Science Approach",
"venue": "",
"year": 2017
},
{
"abstract": "This book is sure to overwhelm a reader by the sheer amount of work the author has done to collect, analyze and present information in a clear manner. When dealing with an extensive subject on materials, any author is confronted by the usual dilemma, whether to take a single group of material and analyze all its properties in one go, or discuss various kinds materials based on any given material property such as structure, thermodynamics, etc. The author has chosen the latter style and has managed to still handle the topics deftly. Upon reading the book this approach does make sense, since any practicing engineer would be constrained to select a material mainly based on the properties and it would make sense to understand the differences/similarities of various materials for any given property under a single heading. The broad topics covered by the book are based on material structure, thermodynamics, kinetic process, transport properties, mechanics, electrical, magnetic and optical properties. Materials have been classified as metals, alloys, ceramics, glasses, polymers, composites and biologics. The last category is especially interesting considering that the author has done considerable study of medical literature. There is a separate chapter on processing of materials and one on case studies. Much use can be derived out of this book even is a student chooses to skip these two chapters. The chapter on case studies is much too short given the vastness of the rest of the material. Then, one could always write a separate book on just the applications alone. The appendices form a useful compendium of commonly used properties and data. One other simple, yet outstanding feature of the book is the historical tidbits of information and biographical sketches of reputed scientists and engineers. Sample problems have been answered then and there, but the fact that the answers have been inverted does not lend itself to the immediate temptation of a student to look at the answer even before making a valiant attempt to solve the problem. This is the first time I am seeing such a simple and efficient technique. Useful hints also guide the student towards the right steps to solve problems. In summary, the author has done an outstanding effort in collecting the vast information on materials and presenting it in a readable form. Even the front and rear inside cover pages have been made useful by way of commonly needed information. In my opinion, the material presented can be used even by engineers of disciplines other than materials and chemical engineers. I would like to caution however, that the book is more of a great reference than a lovable text book.",
"author_names": [
"Sathya Prasad Mangalaramanan"
],
"corpus_id": 136840662,
"doc_id": "136840662",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "A Review of: \"An Introduction to Materials Science and Engineering for Chemical and Materials Engineers\"",
"venue": "",
"year": 2007
},
{
"abstract": "",
"author_names": [
"S M Head"
],
"corpus_id": 137303929,
"doc_id": "137303929",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "A Review of: \"An Introduction to Materials Science and Engineering for Chemical and Materials Engineers\"",
"venue": "",
"year": 2007
},
{
"abstract": "This book provides non specialists with a basic understanding of the underlying concepts of quantum chemistry. It is both a text for second or third year undergraduates and a reference for researchers who need a quick introduction or refresher. All chemists and many biochemists, materials scientists, engineers, and physicists routinely use spectroscopic measurements and electronic structure computations in their work. The emphasis of Quantum Chemistry on explaining ideas rather than enumerating facts or presenting procedural details makes this an excellent foundation text/reference.",
"author_names": [
"Ajit J Thakkar"
],
"corpus_id": 220446297,
"doc_id": "220446297",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Quantum Chemistry: A Concise Introduction for Students of Physics, Chemistry, Biochemistry and Materials Science",
"venue": "",
"year": 2016
},
{
"abstract": "Tienda online donde Comprar Computational Methods in Catalysis and Materials Science: An Introduction for Scientists and Engineers al precio 100,44 EUR de Rutger A. van Santen Philippe Sautet, tienda de Libros de Medicina, Libros de Quimica Quimica",
"author_names": [
"Rutger Anthony van Santen",
"Philippe Sautet"
],
"corpus_id": 107159106,
"doc_id": "107159106",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Comprar Computational Methods in Catalysis and Materials Science: An Introduction for Scientists and Engineers Rutger A. van Santen 9783527320325 Wiley",
"venue": "",
"year": 2009
},
{
"abstract": "The field of environmental engineering traces its origins to the integration of \"civil engineering\" infrastructure and the objectives of \"public health\" namely cost effective disease prevention at the community scale. To address the urgent need to re invigorate the \"ancient\" subspecialization of \"sanitary engineering\" within the field of environmental engineering, a new course was created at the Missouri University of Science and Technology entitled, \"Public Health for Environmental Engineers.\" The new course leverages available online materials disseminated by The Johns Hopkins University as well as materials disseminated by the National Environmental Health Association (NEHA) to emphasize environmental health practice in diverse communities from urban settings in developed nations to rural villages in less developed countries. The new course employs a previously reported format including blended delivery, a flipped classroom, and mastery learning (D.B. Oerther, \"Reducing costs while maintaining learning outcomes using blended, flipped, and mastery pedagogy to teach introduction to environmental engineering,\" in Proceedings of the 2017 ASEE Annual Conference Exposition, Columbus, OH, USA, June 25 28, 2017. [Online] Available: https:/peer.asee.org/28786. [Accessed April 26, 2018] This current article summarizes the course content, pedagogical approach, and the results of assessments of three offerings of \"Public Health for Environmental Engineers\" to a total of 79 students in the Spring Semesters of 2016, 2017, and 2018. According to the results of the assessments, some students resisted the blended learning delivery format (i.e. \"The professor gets paid a lot, and he shouldn't use available online materials for teaching. He should make us purchase a text book and cover it in lecture\" and other students resisted the pedagogical choice of active learning (i.e. \"Complete abuse of power; the professor creates an environment that is not conducive to learning by forcing students to answer questions during discussion\" Other students responded positively to the course content (i.e. \"I learned a lot of practical environmental health information that I plan to use in practice\" Future work should: 1) follow up with students to identify the value of the course in their professional practice after graduation; 2) assess changes in student attitudes and beliefs from before and after the course; and 3) replicate the course at other institutions to evaluate the effectiveness of the course content and delivery approach independent of the personality of the instructor and with a variety of student types.",
"author_names": [
"Daniel B Oerther"
],
"corpus_id": 59496292,
"doc_id": "59496292",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Introduction to Public Health for Environmental Engineers: Results from a Three Year Pilot",
"venue": "",
"year": 2018
},
{
"abstract": "Cindy K. Waters is an Assistant Professor in the Mechanical Engineering at NCA&T State University. She is a B.S. and M.S graduate from Virginia Tech in Materials Science and Engineering Department and a 2004 PhD graduate in Mechanical Engineering, from NCA&T. Her research is in the development and characterization of novel syntactic foams and various porous metals via powder metallurgy and foam casting. She is also significantly involved in engineering education research in the areas of assessment studies of classroom material science pedagogical implementations; case studies in various engineering disciplines and; engineering faculty barriers to adopt evidence based (or nontraditional) teaching methods She serves as the College of Engineering liaison to ASEE and advises the Society of Women Engineers student chapter and leads the students in developing and implementing yearly outreach events for the K 8 female community. She is author of many peer reviewed conference proceeding for the ASEE Annual Meetings and the FIE meetings.",
"author_names": [
"Elliot P Douglas",
"Tim Raymond",
"Cindy Waters",
"William L Hughes",
"Mirka Koro-Ljungberg",
"David Miller"
],
"corpus_id": 56859301,
"doc_id": "56859301",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Use of Process Oriented Guided Inquiry Learning for Introduction to Materials",
"venue": "",
"year": 2014
}
] |
Application of external cavity semiconductor lasers in optical chaos communications | [
{
"abstract": "This paper provides an overview of experimental and theoretical work undertaken in the authors' laboratory and directed at the development of optical chaos communications technology. The specific focus of the paper is on the use of external cavity edge emitting semiconductor lasers for this purpose. Applications to networked chaotic communications will be highlighted.",
"author_names": [
"K Alan Shore",
"M W Lee",
"Jon Paul",
"Y Hong"
],
"corpus_id": 19287771,
"doc_id": "19287771",
"n_citations": 0,
"n_key_citations": 0,
"score": 1,
"title": "Application of external cavity semiconductor lasers in optical chaos communications",
"venue": "2007 Conference on Lasers and Electro Optics Pacific Rim",
"year": 2007
},
{
"abstract": "It is demonstrated that tailored optoelectronic feedback can be used to selectively excite periodic dynamical output from external cavity semiconductor lasers undergoing a period doubling bifurcation cascade on the route to the chaotic coherence collapse regime. The optoelectronic feedback can effectively suppress or invert the bifurcation sequence so that low order periodic motion can be resonantly excited from high order periodic or chaotic dynamics. The application of the technique in chaotic optical communications and its role in chaos control are discussed.",
"author_names": [
"Sergei Turovets",
"Jaume Dellunde",
"K Alan Shore"
],
"corpus_id": 61403997,
"doc_id": "61403997",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Optoelectronic feedback control of laser diodes for chaotic optical communications",
"venue": "Proceedings of GLOBECOM'96. 1996 IEEE Global Telecommunications Conference",
"year": 1996
},
{
"abstract": "It is demonstrated that tailored optoelectronic feedback can be used selectively to excite periodic dynamical output from external cavity semiconductor lasers undergoing a period doubling bifurcation cascade on the route to the chaotic coherence collapse regime. The optoelectronic feedback can effectively suppress or invert the bifurcation sequence so that low order periodic motion can be resonantly excited from high order periodic or chaotic dynamics. The robustness of coherence collapse control to intrinsic laser diode noise is investigated. The application of the technique in chaotic communications and its role in chaos control are discussed.",
"author_names": [
"Sergei Turovets",
"Jaume Dellunde",
"K Alan Shore"
],
"corpus_id": 121302970,
"doc_id": "121302970",
"n_citations": 37,
"n_key_citations": 0,
"score": 0,
"title": "Nonlinear dynamics of a laser diode subjected to both optical and electronic feedback",
"venue": "",
"year": 1997
},
{
"abstract": "An external cavity semiconductor laser (ECSL) outputs high dimensional chaos, which has potential for various applications, but the unwanted time delay signature (TDS) might compromise the performance. In this work, a highly integrated and extensible framework of phased array semiconductor lasers, operating in a steady state when isolated, is employed to postprocess the original chaos generated by an ECSL. Our results demonstrate that such a compact active device enables TDS suppression over wide parameter space. Better performance can be achieved in the proposed scheme compared with the conventional, discrete semiconductor laser subjected to optical chaotic injection. The influence of the injection parameters and the laser separation is studied, which further confirms the feasibility of the proposed scheme for TDS suppression. The phased array can be readily extended to include a large number of elements, and thus the current scheme allows for the generation of multiple independent chaotic signals with no discernible TDS in parallel. This means that the current study may pave the way for parallel random number generation based on optical chaos.",
"author_names": [
"Pei Zhou",
"Qi Fang",
"Nianqiang Li"
],
"corpus_id": 214003491,
"doc_id": "214003491",
"n_citations": 7,
"n_key_citations": 1,
"score": 0,
"title": "Phased array assisted time delay signature suppression in the optical chaos generated by an external cavity semiconductor laser",
"venue": "",
"year": 2020
},
{
"abstract": "Quantum cascade lasers (QCLs) are unipolar semiconductor lasers offering access to wavelengths from the mid infrared (IR) to the terahertz domain and promising impact on various applications such as free space communications, high resolution spectroscopy, LIDAR remote sensing or optical countermeasures. Unlike bipolar semiconductor lasers, stimulated emission in QCLs is obtained via electronic transitions between discrete energy states inside the conduction band. Recent technological progress has led to QCLs operating in pulsed or continuous wave mode, at room temperature in single or multi mode operation, with high powers up to a few watts for mid IR devices. This spectacular development raises multiple interrogations on the stability of QCLs as little is known on their dynamical properties. Very recently, experiments based on optical spectrum measurements have unveiled the existence of five distinct feedback regimes without, however, identifying the complex dynamics dwelling within the QCL. In this article we provide the first experimental evidence of a route to chaos in a QCL emitting at mid IR wavelength. When applying optical feedback with an increasing strength, the QCL dynamics bifurcate to periodic dynamics at the external cavity frequency and later to chaos without an undamping of relaxation oscillations, hence contrasting with the well known scenarios occurring in interband laser diodes.",
"author_names": [
"Frederic Grillot",
"Louise Jumpertz",
"K Schires",
"Mathieu Carras",
"Marc Sciamanna"
],
"corpus_id": 124023473,
"doc_id": "124023473",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Deterministic temporal chaos from a mid infrared external cavity quantum cascade lasers",
"venue": "SPIE OPTO",
"year": 2016
},
{
"abstract": "",
"author_names": [
"John G McInerney"
],
"corpus_id": 124027014,
"doc_id": "124027014",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Development of optical chaos through self pulsations in external cavity semiconductor lasers",
"venue": "",
"year": 1991
},
{
"abstract": "We propose and numerically demonstrate the generation of wideband millimeter wave (mmW) flat chaos with controllable power spectrum by injection of chaotic signal from external cavity semiconductor laser (ECSL) into optical time lens with noise phase modulation. Simulation results indicate consistent elimination of the ECSL relaxation oscillation frequency domination over the RF spectrum for large scale parameters of the optical time lens module and a wideband flat chaos, whose efficient bandwidth rapidly increases with the bandwidth of the noise signal driving the phase modulator and phase modulation index. Besides, we show that the time delay signature suppression can be concurrently achieved for moderate values of the noise bandwidth and phase modulation index. The proposed wideband mmW flat chaos exhibits great potential applications for ultrahigh speed chaos communications, mmW radars and macroscopic mmW noise source required for mmW research and design.",
"author_names": [
"Romain Zinsou",
"Pu Li",
"Zhensen Gao",
"Yanhui Sun",
"Yuncai Wang"
],
"corpus_id": 229642847,
"doc_id": "229642847",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Wideband Millimeter Wave Flat Chaos Generation With Controllable Power Spectrum Using Optical Time Lens",
"venue": "IEEE Photonics Journal",
"year": 2021
},
{
"abstract": "The optical feedback dynamics of two multimode InAs/GaAs quantum dot lasers emitting exclusively on sole ground or excited lasing states is investigated. The transition from longto short delay regimes is analyzed, while the boundaries associated to the birth of periodic and chaotic oscillations are unveiled to be a function of the external cavity length. The results show that depending on the initial lasing state, different routes to chaos are observed. These results are of importance for the development of isolator free transmitters in short reach networks. (c) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement OCIS codes: (140.5960) Semiconductor lasers; (250.0250) Optoelectronics; (190.3100) Instabilities and chaos. References and links 1. C. F. Lam, H. Liu, and R. Urata, \"What devices do data centers need?\" in Optical Fiber Communications Conference and Exhibition (OFC) of 2014 OSA Technical Digest Series (Optical Society of America, 2014) paper M2K.5. 2. Cisco white paper, \"The Zettabyte Era: Trends and Analysis\" (Cisco, 2016) 3. D. Bimberg, \"Quantum dot based nanophotonics and nanoelectronics,\" Electron. Lett. 44, 390 (2008) 4. G. Eisenstein and D. Bimberg, eds. Green Photonics and Electronics (Springer, 2017) 5. M. T. Crowley, N. A. Naderi, H. Su, F. Grillot, and L. F. Lester, \"GaAs Based Quantum Dot Lasers,\" in Advances in Semiconductor Lasers, J. J. Coleman, A. Bryce, and C. Jagadish, eds. (Academic Press, 2012) pp. 371 417 6. M. Grundmann, ed. Nano Optoelectronics, NanoScience and Technology (Springer, 2002) 7. K. Nishi, K. Takemasa, M. Sugawara, and Y. Arakawa, \"Development of quantum dot lasers for data com and silicon photonics applications,\" IEEE J. Sel. Topics Quantum Electron. 23, 1 7 (2017) 8. A. Y. Liu, S. Srinivasan, J. Norman, A. C. Gossard, and J. E. Bowers, \"Quantum dot lasers for silicon photonics,\" Photonics Res. 3, B1 (2015) 9. S. Chen, W. Li, J. Wu, Q. Jiang, M. Tang, S. Shutts, S. N. Elliott, A. Sobiesierski, A. J. Seeds, I. Ross, P. M. Smowton, and H. Liu, \"Electrically pumped continuous wave III V quantum dot lasers on silicon,\" Nat. Photonics 10, 307 311 (2016) 10. Ranovus Inc. \"Ranovus announces availability of world's first quantum dot multi wavelength laser and silicon photonics platform technologies to create a new cost and power consumption paradigm for DCI market,\" (Ranovus, 2016) http:/ranovus.com/worlds first quantum dot multi wavelength laser and silicon photonics platformtechnologies for dci market/ 11. Y. Urino, N. Hatori, K. Mizutani, T. Usuki, J. Fujikata, K. Yamada, T. Horikawa, T. Nakamura, and Y. Arakawa, \"First demonstration of athermal silicon optical interposers with quantum dot lasers operating up to 125 *C,\" J. Lightw. Technol. 33, 1223 1229 (2015) 12. N. Zhuo, J. C. Zhang, F. J. Wang, Y. H. Liu, S. Q. Zhai, Y. Zhao, D. B. Wang, Z. W. Jia, Y. H. Zhou, L. J. Wang, J. Q. Liu, S. M. Liu, F. Q. Liu, Z. G.Wang, J. B. Khurgin, and G. Sun, \"Room temperature continuous wave quantum dot cascade laser emitting at 7.2 mm,\" Opt. Express 25, 13807 13815 (2017) Vol. 26, No. 2 22 Jan 2018 OPTICS EXPRESS 1743 #318053 https:/doi.org/10.1364/OE.26.001743 Journal (c) 2018 Received 19 Dec 2017; accepted 8 Jan 2018; published 16 Jan 2018 13. A. Spott, E. J. Stanton, N. Volet, J. D. Peters, J. R. Meyer, and J. E. Bowers, \"Heterogeneous integration for mid infrared silicon photonics,\" IEEE J. Sel. Top. Quantum Electron. 23, 1 10 (2017) 14. D. O'Brien, S. Hegarty, G. Huyet, J. McInerney, T. Kettler, M. Laemmlin, D. Bimberg, V. Ustinov, A. Zhukov, S. Mikhrin, and A. Kovsh, \"Feedback sensitivity of 1.3 mm InAs/GaAs quantum dot lasers,\" Electron. Lett. 39, 1819 (2003) 15. K. Mizutani, K. Yashiki, M. Kurihara, Y. Suzuki, Y. Hagihara, N. Hatori, T. Shimizu, Y. Urino, T. Nakamura, K. Kurata, and Y. Arakawa, \"Optical I/O core transmitter with high tolerance to optical feedback using quantum dot laser,\" in 2015 European Conference on Optical Communication (ECOC) (2015) paper 0263. 16. D. Arsenijevic and D. Bimberg, \"Quantum dot lasers for 35 gbit/s pulse amplitude modulation and 160 gbit/s differential quadrature phase shift keying,\" Proc. SPIE 9892, 9892 (2016) 17. C. Wang, B. Lingnau, K. Ludge, J. Even, and F. Grillot, \"Enhanced dynamic performance of quantum dot semiconductor lasers operating on the excited state,\" IEEE J. Quantum Electron. 50, 723 731 (2014) 18. Z. R. Lv, H. M. Ji, X. G. Yang, S. Luo, F. Gao, F. Xu, and T. Yang, \"Large Signal Modulation Characteristics in the Transition regime for two state lasing quantum dot lasers,\" Chinese Phys. Lett. 33, 124204 (2016) 19. B. J. Stevens, D. T. D. Childs, H. Shahid, and R. A. Hogg, \"Direct modulation of excited state quantum dot lasers,\" Appl. Phys. Lett. 95, 061101 (2009) 20. D. Arsenijevic, A. Schliwa, H. Schmeckebier, M. Stubenrauch, M. Spiegelberg, D. Bimberg, V. Mikhelashvili, and G. Eisenstein, \"Comparison of dynamic properties of groundand excited state emission in p doped InAs/GaAs quantum dot lasers,\" Appl. Phys. Lett. 104, 181101 (2014) 21. F. Grillot, B. Dagens, J. G. Provost, H. Su, and L. F. Lester, \"Gain compression and above threshold linewidth enhancement factor in 1.3 mm InAs GaAs quantum Dot lasers,\" IEEE J. Quantum Electron. 44, 946 951 (2008) 22. F. Zubov, M. Maximov, E. Moiseev, A. Savelyev, Y. Shernyakov, D. Livshits, N. Kryzhanovskaya, and A. Zhukov, \"Observation of zero linewidth enhancement factor at excited state band in quantum dot laser,\" Electron. Lett. 51, 1686 1688 (2015) 23. C. Mesaritakis, C. Simos, H. Simos, S. Mikroulis, I. Krestnikov, E. Roditi, and D. Syvridis, \"Effect of optical feedback to the ground and excited state emission of a passively mode locked quantum dot laser,\" Appl. Phys. Lett. 97, 061114 (2010) 24. A. Rohm, B. Lingnau, and K. Ludge, \"Ground state modulation enhancement by two state lasing in quantum dot laser devices,\" Appl. Phys. Lett. 106, 1 6 (2015) 25. F. Grillot, N. A. Naderi, J. B. Wright, R. Raghunathan, M. T. Crowley and L. F. Lester, \"A dual mode quantum dot laser operating in the excited state,\" Appl. Phys. Lett. 99, 1110 1113 (2011) 26. J. D. Walker, D. M. Kuchta, and J. S. Smith, \"Wafer scale uniformity of vertical cavity lasers grown by modified phase locked epitaxy technique,\" Electron. Lett. 29, 239 240 (1993) 27. H. Huang, D. Arsenijevic, K. Schires, T. Sadeev, D. Bimberg, and F. Grillot, \"Multimode optical feedback dynamics of InAs/GaAs quantum dot lasers emitting on different lasing states,\" AIP Adv. 6, 125114 (2016) 28. A. Kovsh, N. Maleev, A. Zhukov, S. Mikhrin, A. Vasil'ev, E. Semenova, Y. Shernyakov, M. Maximov, D. Livshits, V. Ustinov, N. Ledentsov, D. Bimberg, and Z. Alferov, \"InAs/InGaAs/GaAs quantum dot lasers of 1.3 mm range with enhanced optical gain,\" J. Cryst. Growth 251, 729 736 (2003) 29. O. Stier, M. Grundmann, and D. Bimberg, \"Electronic and optical properties of strained quantum dots modeled by 8 band k*p theory,\" Phys. Rev. B 59, 5688 (1999) 30. A. Schliwa, M. Winkelnkemper, and D. Bimberg, \"Few particle energies versus geometry and composition of InxGa1x As/GaAs self organized quantum dots,\" Phys. Rev. B 79, 075443 (2009) 31. N. Schunk and K. Petermann, \"Stability analysis for laser diodes with short external cavities,\" IEEE Photon. Technol. Lett. 1, 49 51 (1989) 32. J. Ohtsubo, Semiconductor Lasers: Stability, Instability and Chaos, Springer Series in Optical Sciences (Springer, 2010) 33. J. P. Toomey, D. M. Kane, C. McMahon, A. Argyris, and D. Syvridis, \"Integrated semiconductor laser with optical feedback: transition from short to long cavity regime,\" Opt. Express 23, 18754 (2015) 34. N. Gavra and M. Rosenbluh, \"Behavior of the relaxation oscillation frequency in vertical cavity surface emitting laser with external feedback,\" J. Opt. Soc. Am. B 27, 2482 2487 (2010) 35. M. Stubenrauch, G. Stracke, D. Arsenijevic, A. Strittmatter, and D. Bimberg, \"15 Gb/s index coupled distributed feedback lasers based on 1.3 mm InGaAs quantum dots,\" Appl. Phys. Lett. 105, 011103 (2014)",
"author_names": [
"H Uang",
"IN LYU-CHIHL",
"Christian Hen",
"D Ejan A Rsenijevic",
"D Ieter B Imberg",
"F Rederic G Rillot"
],
"corpus_id": 49657772,
"doc_id": "49657772",
"n_citations": 5,
"n_key_citations": 1,
"score": 0,
"title": "Multimode optical feedback dynamics in InAs GaAs quantum dot lasers emitting exclusively on ground or excited states transition from short to long delay regimes",
"venue": "",
"year": 2018
},
{
"abstract": "Quantum cascade lasers (QCLs) exploit radiative intersubband transitions within the conduction band of semiconductor heterostructures. The wide range of wavelengths achievable with QCLs, from mid infrared to terahertz range, leads to a large number of applications including absorption spectroscopy, optical countermeasures and free space communications requiring stable single mode operation with a narrow linewidth, high output power and high modulation bandwidth. Prior work has unveiled the occurrence of temporal chaos in a QCL subjected to optical feedback, with a scenario involving oscillations at the external cavity frequency and low frequency fluctuations. The purpose of this work is to further investigate the temperature dependence of a mid infrared QCL with optical feedback. When the semiconductor device is cooled down to 170K, experiments unveil that the laser destabilization appears at a lower feedback ratio and that the chaotic bubble slightly expands owing to a different carrier lifetime dynamics. These results are of paramount importance for new mid infrared applications such as chaos encrypted free space communications or unpredictable countermeasures.",
"author_names": [
"Olivier Spitz",
"Jiagui Wu",
"Sudeep Khanal",
"Mathieu Carras",
"Benjamin S Williams",
"C W Wong",
"Frederic Grillot"
],
"corpus_id": 125875402,
"doc_id": "125875402",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Temperature dependence of a mid infrared quantum cascade laser with external optical feedback",
"venue": "OPTO",
"year": 2018
},
{
"abstract": "A simple method of targeting periodic dynamics appearing in semiconductor lasers subject to optical feedback is demonstrated. Possible applications of the technique in chaotic communications are identified, and its advantages for chaos control are discussed.",
"author_names": [
"Lloyd N Langley",
"Sergei Turovets",
"K Alan Shore"
],
"corpus_id": 45378646,
"doc_id": "45378646",
"n_citations": 9,
"n_key_citations": 0,
"score": 0,
"title": "Targeting periodic oscillations of external cavity laser diodes.",
"venue": "Optics letters",
"year": 1995
}
] |
Recent advances in ZnO nanostructures and thin films for biosensor applications: Review | [
{
"abstract": "Biosensors have shown great potential for health care and environmental monitoring. The performance of biosensors depends on their components, among which the matrix material, i.e. the layer between the recognition layer of biomolecule and transducer, plays a crucial role in defining the stability, sensitivity and shelf life of a biosensor. Recently, zinc oxide (ZnO) nanostructures and thin films have attracted much interest as materials for biosensors due to their biocompatibility, chemical stability, high isoelectric point, electrochemical activity, high electron mobility, ease of synthesis by diverse methods and high surface to volume ratio. ZnO nanostructures have shown the binding of biomolecules in desired orientations with improved conformation and high biological activity, resulting in enhanced sensing characteristics. Furthermore, compatibility with complementary metal oxide semiconductor technology for constructing integrated circuits makes ZnO nanostructures suitable candidate for future small integrated biosensor devices. This review highlights recent advances in various approaches towards synthesis of ZnO nanostructures and thin films and their applications in biosensor technology.",
"author_names": [
"Sunil K Arya",
"Shibu Saha",
"Jaime E Ramirez-Vick",
"Vinay Gupta",
"Shekhar Bhansali",
"Surinder P Singh"
],
"corpus_id": 40023506,
"doc_id": "40023506",
"n_citations": 435,
"n_key_citations": 4,
"score": 1,
"title": "Recent advances in ZnO nanostructures and thin films for biosensor applications: review.",
"venue": "Analytica chimica acta",
"year": 2012
},
{
"abstract": "ZnO nanostructured materials, such as films and nanoparticles, could provide a suitable platform for development of high performance biosensors due to their unique fundamental material properties.The performance of biosensors depends on their components, among which the matrix material, i.e. the layer between the recognition layer of bio molecule and transducer, plays a crucial role in defining the stability, sensitivity and shelf life of a biosensor. This paper reviews different preparation techniques of ZnOnanocrystals. Efforts are made to summarize and analyze existing results regarding surface modification for successful biofunctionalization and understanding of the mechanisms involved.",
"author_names": [
"Ravi C Bharamagoudar",
"A S Patil"
],
"corpus_id": 16365060,
"doc_id": "16365060",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "A Comprehensive Review of ZnO nanostructures and thin films for biosensor applications",
"venue": "",
"year": 2015
},
{
"abstract": "Zinc oxide is a unique material that exhibits semiconducting and piezoelectric dual properties. Using a solid vapour phase thermal sublimation technique, nanocombs, nanorings, nanohelixes/nanosprings, nanobelts, nanowires and nanocages of ZnO have been synthesized under specific growth conditions. These unique nanostructures unambiguously demonstrate that ZnO probably has the richest family of nanostructures among all materials, both in structures and in properties. The nanostructures could have novel applications in optoelectronics, sensors, transducers and biomedical sciences. This article reviews the various nanostructures of ZnO grown by the solid vapour phase technique and their corresponding growth mechanisms. The application of ZnO nanobelts as nanosensors, nanocantilevers, field effect transistors and nanoresonators is demonstrated.",
"author_names": [
"Zhong Lin Wang"
],
"corpus_id": 15816304,
"doc_id": "15816304",
"n_citations": 3070,
"n_key_citations": 54,
"score": 0,
"title": "Zinc oxide nanostructures: growth, properties and applications",
"venue": "",
"year": 2004
},
{
"abstract": "This article reviews the recent progress in optical biosensors that use the label free detection protocol, in which biomolecules are unlabeled or unmodified, and are detected in their natural forms. In particular, it will focus on the optical biosensors that utilize the refractive index change as the sensing transduction signal. Various optical label free biosensing platforms will be introduced, including, but not limited to, surface plasmon resonance, interferometers, waveguides, fiber gratings, ring resonators, and photonic crystals. Emphasis will be given to the description of optical structures and their respective sensing mechanisms. Examples of detecting various types of biomolecules will be presented. Wherever possible, the sensing performance of each optical structure will be evaluated and compared in terms of sensitivity and detection limit.",
"author_names": [
"Xudong Fan",
"Ian M White",
"Siyka I Shopova",
"Hongying Zhu",
"J D Suter",
"Yuze Sun"
],
"corpus_id": 10346035,
"doc_id": "10346035",
"n_citations": 1819,
"n_key_citations": 44,
"score": 0,
"title": "Sensitive optical biosensors for unlabeled targets: a review.",
"venue": "Analytica chimica acta",
"year": 2008
},
{
"abstract": "Wurtzitic ZnO is a wide bandgap (3.437 eV at 2 K) semiconductor which has many applications, such as piezoelectric transducers, varistors, phosphors, and transparent conducting films. Most of these applications require only polycrystalline material; however, recent successes in producing large area single crystals have opened up the possibility of producing blue and UV light emitters, and high temperature, high power transistors. The main advantages of ZnO as a light emitter are its large exciton binding energy (60 meV) and the existence of well developed bulk and epitaxial growth processes; for electronic applications, its attractiveness lies in having high breakdown strength and high saturation velocity. Optical UV lasing, at both low and high temperatures, has already been demonstrated, although efficient electrical lasing must await the further development of good, p type material. ZnO is also much more resistant to radiation damage than are other common semiconductor materials, such as Si, GaAs, CdS, and even GaN; thus, it should be useful for space applications.",
"author_names": [
"David C Look"
],
"corpus_id": 98615926,
"doc_id": "98615926",
"n_citations": 2419,
"n_key_citations": 17,
"score": 0,
"title": "Recent Advances in ZnO Materials and Devices",
"venue": "",
"year": 2001
},
{
"abstract": "This paper reviews recent advances in the modification of graphene and the fabrication of graphene based polymer nanocomposites. Recently, graphene has attracted both academic and industrial interest because it can produce a dramatic improvement in properties at very low filler content. The modification of graphene/graphene oxide and the utilization of these materials in the fabrication of nanocomposites with different polymer matrixes have been explored. Different organic polymers have been used to fabricate graphene filled polymer nanocomposites by a range of methods. In the case of modified graphene based polymer nanocomposites, the percolation threshold can be achieved at a very lower filler loading. Herein, the structure, preparation and properties of polymer/graphene nanocomposites are discussed in general along with detailed examples drawn from the scientific literature.",
"author_names": [
"Tapas Kuilla",
"Sambhu Bhadra",
"Da-hu Yao",
"Nam Hoon Kim",
"Saswata Bose",
"Joong Hee Lee"
],
"corpus_id": 137548823,
"doc_id": "137548823",
"n_citations": 2698,
"n_key_citations": 46,
"score": 0,
"title": "Recent advances in graphene based polymer composites",
"venue": "",
"year": 2010
},
{
"abstract": "This article provides a comprehensive review of current research activities that concentrate on one dimensional (1D) nanostructures wires, rods, belts, and tubes whose lateral dimensions fall anywhere in the range of 1 to 100 nm. We devote the most attention to 1D nanostructures that have been synthesized in relatively copious quantities using chemical methods. We begin this article with an overview of synthetic strategies that have been exploited to achieve 1D growth. We then elaborate on these approaches in the following four sections: i) anisotropic growth dictated by the crystallographic structure of a solid material; ii) anisotropic growth confined and directed by various templates; iii) anisotropic growth kinetically controlled by supersaturation or through the use of an appropriate capping reagent; and iv) new concepts not yet fully demonstrated, but with long term potential in generating 1D nanostructures. Following is a discussion of techniques for generating various types of important heterostructured nanowires. By the end of this article, we highlight a range of unique properties (e.g. thermal, mechanical, electronic, optoelectronic, optical, nonlinear optical, and field emission) associated with different types of 1D nanostructures. We also briefly discuss a number of methods potentially useful for assembling 1D nanostructures into functional devices based on crossbar junctions, and complex architectures such as 2D and 3D periodic lattices. We conclude this review with personal perspectives on the directions towards which future research on this new class of nanostructured materials might be directed.",
"author_names": [
"Younan Xia",
"Peidong Yang",
"Yugang Sun",
"Yiying Wu",
"Brian T Mayers",
"Byron D Gates",
"Yadong Yin",
"Franklin Kim",
"Haoquan Yan"
],
"corpus_id": 15196064,
"doc_id": "15196064",
"n_citations": 7118,
"n_key_citations": 26,
"score": 0,
"title": "One Dimensional Nanostructures: Synthesis, Characterization, and Applications",
"venue": "",
"year": 2003
},
{
"abstract": "",
"author_names": [
"Elvira Fortunato",
"Pedro Barquinha",
"Rodrigo Martins"
],
"corpus_id": 196953799,
"doc_id": "196953799",
"n_citations": 586,
"n_key_citations": 29,
"score": 0,
"title": "Oxide Semiconductor Thin Film Transistors: A Review of Recent Advances",
"venue": "",
"year": 2012
},
{
"abstract": "Foreword 1. Basic Properties and Applications of ZnO (V.A. Coleman and C. Jagadish) 2. Doping and Defects in ZnO (D.C. Look) 3. Synthesis and Characterization of Nitrogen Doped ZnO Films Grown by MOCVD (T.J. Coutts, Xiaonan Li, T. Barnes, B. Keyes, C.L. Perkins, S.E. Asher, Shengbai Zhang, Su Huai Wei and S. Limpijumnong) 4. Pulsed Laser Deposition of ZnO (V. Gupta and K. Sreenivas) 5. Optical Properties of ZnO and Related Alloys (U. Ozgur and H. Morkoc) 6. Minority Carrier Transport in ZnO and Related Materials (O. Lopatiuk, A. Osinsky and L. Chernyak) 7. Contacts to ZnO (Jae Hong Lim and Seong Ju Park) 8. Ion Implantation into ZnO (S.O. Kucheyev and C. Jagadish) 9. Advances in Processing of ZnO (K. Ip, S.J. Pearton, D.P. Norton and F. Ren) 10. Novel Nanostructures and Nanodevices of ZnO (Zhong Lin Wang) 11. ZnO/ZnMgO heterojunction FETs (M. Yano, K. Koike, S. Sasa and M. Inoue) 12.ZnO Thin Film Transistors (R. Hoffman) 13. ZnO Piezoelectric Devices (Yicheng Lu, N. Emanetoglu and Ying Chen) 14. Gas, Chemical and Biological Sensing with ZnO (Young Woo Heo, F. Ren and D.P. Norton) 15. ZnO Based Light Emitters (A. Osinsky and S. Karpov) 16. Ferromagnetism in ZnO Doped With Transition Metal Ions (D.P. Norton, S.J. Pearton, J.M. Zavada, W.M. Chen and I.A. Bouyanova)",
"author_names": [
"Chennupati Jagadish",
"Stephen J Pearton"
],
"corpus_id": 92960322,
"doc_id": "92960322",
"n_citations": 836,
"n_key_citations": 27,
"score": 0,
"title": "Zinc oxide bulk, thin films and nanostructures processing, properties and applications",
"venue": "",
"year": 2006
},
{
"abstract": "In recent years there has been great progress the application of nanomaterials in biosensors. The importance of these to the fundamental development of biosensors has been recognized. In particular, nanomaterials such as gold nanoparticles, carbon nanotubes, magnetic nanoparticles and quantum dots have been being actively investigated for their applications in biosensors, which have become a new interdisciplinary frontier between biological detection and material science. Here we review some of the main advances in this field over the past few years, explore the application prospects, and discuss the issues, approaches, and challenges, with the aim of stimulating a broader interest in developing nanomaterial based biosensors and improving their applications in disease diagnosis and food safety examination.",
"author_names": [
"Xueqing Zhang",
"Qin Guo",
"Daxiang Cui"
],
"corpus_id": 504531,
"doc_id": "504531",
"n_citations": 254,
"n_key_citations": 4,
"score": 0,
"title": "Recent Advances in Nanotechnology Applied to Biosensors",
"venue": "Sensors",
"year": 2009
}
] |
ZnO— nanostructures, defects, and devices Mater | [
{
"abstract": "Zinc oxide and related compound semiconductors (CdO, MgO) have drawn considerable interest in recent years due to their suitability for visible and UV light emitters and detectors, as well as for high temperature electronics. This volume, first published in 2007, brings together researchers and technologists from academia, industry and government laboratories around the world, all working in various aspects of ZnO and related materials. In addition to fundamental materials science issues, the volume focuses on device design, processing, and technology of photonic and electronic devices including light emitting diodes and gas, chemical and biosensors. Topics include: devices; defects; spintronics and magnetism; growth; optical properties and nanostructures; doping and processing TFTs.",
"author_names": [
"Jurgen Christen",
"Related Materials"
],
"corpus_id": 137678809,
"doc_id": "137678809",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Zinc oxide and related materials symposium held November 27 30, 2006, Boston, Massachusetts, U.S.A.",
"venue": "",
"year": 2007
},
{
"abstract": "ZnO has received much attention over the past few years because it has a wide range of properties that depend on doping, including a range of conductivity from metallic to insulating (including n type and p type conductivity) high transparency, piezoelectricity, wide bandgap semiconductivity, room temperature ferromagnetism, and huge magneto optic and chemical sensing effects. Without much effort, it can be grown in many different nanoscale forms, thus allowing various novel devices to be achieved. We review recent studies of ZnO nanostructures, fabrication, novel device applications, and its potential as an electron acceptor material in hybrid solar cells. Control of its rich defect chemistry, which is critical for controlling properties but has not been widely addressed in the context of novel applications, is also discussed.",
"author_names": [
"Lukas Schmidt-Mende",
"Judith L MacManus-Driscoll"
],
"corpus_id": 135655358,
"doc_id": "135655358",
"n_citations": 1580,
"n_key_citations": 15,
"score": 1,
"title": "ZnO nanostructures, defects, and devices",
"venue": "",
"year": 2007
},
{
"abstract": "The interest in ZnO structures has increased drastically in recent years. Intense research by many different groups has focused on novel nanostructures with different shapes ranging from nanowires to nanobelts and even nanosprings. The number of reviews on ZnO is increasing (see for example1 9) The topic of p doping is especially difficult and has been investigated by different groups10 13. ZnO is a direct wide bandgap ~3.3 eV)2 material with a large exciton binding energy of 60 meV. This makes it interesting as a laser material based on exciton recombination at room temperature or even higher. Such a large amount of research on ZnO nanomaterials makes it hard to summarize the work in a systematic way. In this article, we first describe different synthesis routes toward a large variety of nanostructures. The first approach is chemical vapor deposition; certainly one of the most common routes for the synthesis of nanowires, nanobelts, nanosprings, and nanorings. Aqueous solution growth has also attracted great interest. This method allows growth of nanowires and other nanostructures at low temperatures. We describe this method in some detail. Similar to aqueous solution growth, electrodeposition of ZnO nanocolumns can be performed at low temperatures, and this is also briefly described. A very important issue is the doping of ZnO nanowires. We give an introduction into the defect states of ZnO and describe different examples where doping of ZnO nanowires and thin films has been performed. The last section focuses on applications of ZnO nanowires. We describe their use as sensors and cantilevers, as well as their ZnO has received much attention over the past few years because it has a wide range of properties that depend on doping, including a range of conductivity from metallic to insulating (including n type and p type conductivity) high transparency, piezoelectricity, wide bandgap semiconductivity, room temperature ferromagnetism, and huge magnetooptic and chemical sensing effects. Without much effort, it can be grown in many different nanoscale forms, thus allowing various novel devices to be achieved. We review recent studies of ZnO nanostructures, fabrication, novel device applications, and its potential as an electronacceptor material in hybrid solar cells. Control of its rich defect chemistry, which is critical for controlling properties but has not been widely addressed in the context of novel applications, is also discussed.",
"author_names": [
"Lukas Schmidt-Mende",
"Judith L MacManus-Driscoll"
],
"corpus_id": 17198749,
"doc_id": "17198749",
"n_citations": 28,
"n_key_citations": 0,
"score": 0,
"title": "ZnO nanostructures defects and devices REVIEW",
"venue": "",
"year": 2007
},
{
"abstract": "Abstract The significant effect of electrically active defects present in the device, which limits the carrier mobility, generated due to cobalt doping via the co precipitation technique in a ZnO matrix, has been investigated on the basis of its structural, optical and charge transient behaviours. The variations observed in the absorbance and extinction coefficients as a function of wave length reveal the presence of defect states, a range of localized states and structural disorder. The presence of a non uniform trap centre density in the material has been measured on the basis of different operational modes in charge deep level transient spectroscopic analysis. A disparity of such a kind in the structures at the nanoscale will provide for a remarkable approach to improve the performance and reliability of the smart electronic, optoelectronics, photonics and sensing devices.",
"author_names": [
"Amir Zia",
"S Ahmed",
"M Umair Ali"
],
"corpus_id": 125329489,
"doc_id": "125329489",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Defects anomaly in cobalt doped ZnO nanostructures using optical and charge transient analysis",
"venue": "Chinese Journal of Physics",
"year": 2019
},
{
"abstract": "Zinc oxide (ZnO) nanostructures were synthesized in the form of nanoparticles, nanoflowers and nanourchins. Structural, electronic and optical characterization of the samples was performed via standard techniques such as X ray diffraction (XRD) scanning electron microscopy (SEM) photoluminescence, Raman and ultraviolet visible (UV Vis) spectroscopy. Point defect structures which are specific to each morphology have been investigated in terms of their concentration and location via state of the art electron paramagnetic resonance (EPR) spectroscopy. According to the core shell model, all the samples revealed core defects; however, the defects on the surface are smeared out. Finally, all three morphologies have been tested as electrode materials in a real supercapacitor device and the performance of the device, in particular, the specific capacitance and the storage mechanism, has been mediated by the point defects. Morphology dependent defective ZnO electrodes enable the monitoring of the working principle of the supercapacitor device ranging from electric double layer capacitors (EDLC) to pseudo supercapacitors.",
"author_names": [
"Sumaiyah Najib",
"Feray Bakan",
"Nazrin Abdullayeva",
"Rahim Bahariqushchi",
"Sibel Kasap",
"G Franzo",
"Mehmet Sankir",
"Nurdan Demirci Sankir",
"Salvo Mirabella",
"Emre Erdem"
],
"corpus_id": 220718403,
"doc_id": "220718403",
"n_citations": 23,
"n_key_citations": 0,
"score": 0,
"title": "Tailoring morphology to control defect structures in ZnO electrodes for high performance supercapacitor devices.",
"venue": "Nanoscale",
"year": 2020
},
{
"abstract": "One dimensional (1D) ZnO nanostructures have shown great potential in electronics, optoelectronics and electromechanical devices owing to their unique physical and chemical properties. Most of these nanostructures were grown by equilibrium processes where the defects density is controlled by thermodynamic equilibrium. In this work, flash sintering, a non equilibrium field assisted processing method, has been used to synthesize ZnO nanostructures. By applying a high electric field and limiting a low current flow, ZnO nanorods grew uniformly by a vapor liquid solid mechanism due to the extreme temperatures achieved near the hot spot. A high density of basal stacking faults in the nanorods along with ultraviolet excitonic emission and a yellow red emission under room temperature demonstrate the potential of defect engineering in nanostructures via the field assisted growth method.",
"author_names": [
"Xin Li Phuah",
"Jaehun Cho",
"Akriti Akriti",
"Letian Dou",
"Wolfgang Rheinheimer",
"Edwin R Garcia",
"Xingtong Zhang",
"Haiyan Wang"
],
"corpus_id": 227037018,
"doc_id": "227037018",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Field assisted growth of one dimensional ZnO nanostructures with high defect density.",
"venue": "Nanotechnology",
"year": 2020
},
{
"abstract": "Abstract The observation of feeble ferroelectricity and giant piezoelectricity in doped II VI ZnO binary semiconductor has inspired a great deal of research interest, which could pave the way to reduce the toxic effects on the environment, and to develop small molecule ferroelectrics and flexible piezoelectric nanogenerator. The main challenge for practical application of the ZnO is the attainment of a high Curie temperature to be compatible with junction temperatures. This review focuses primarily on the piezoelectric and ferroelectric properties of zinc oxide (ZnO) nanostructures. One of the desirable outcomes is to provide a useful insight into various processes which may induce ferroelectricity and enhance piezoelectricity in non ferroelectric and weak piezoelectric ZnO. Taking into consideration the recent progress in this area, topics such as local switchable polarization, effects of defects, ionic charge of the dopant and ionic size of the dopant, and their contributions to piezoelectric and ferroelectric properties of ZnO are discussed. A critical review of the question dealing with the origin of ferroelectricity in ZnO is given. In a similar vein, methods for enhancing piezoelectric coefficient of ZnO are briefly discussed, followed by their applications in potential devices. From this review, it can be concluded that ZnO (a lead free and biocompatible material) on being doped with suitable dopants show king sized piezoelectric response and feeble ferroelectric response, which possibly make ZnO an attractive alternative to lead based perovskites for specific applications. This subject is of current interest to various scientists worldwide and hence, motivated us to write a review article with an aim that it would give further momentum to the scientists already working in this field.",
"author_names": [
"Sahil Goel",
"Binay Kumar"
],
"corpus_id": 210513280,
"doc_id": "210513280",
"n_citations": 24,
"n_key_citations": 0,
"score": 0,
"title": "A review on piezo /ferro electric properties of morphologically diverse ZnO nanostructures",
"venue": "",
"year": 2020
},
{
"abstract": "In this work, a highly visible blind UV photodetector with a large photo responsivity using ZnO nanostructures is demonstrated. A large photoconductive gain of 2050 and external quantum efficiency of <inline formula> <tex math notation=\"LaTeX\"$2.05\\times 10 {5} /tex math>/inline formula> at 350 nm (illumination intensity of 1 mW/cm<sup>2</sup> incident radiation has been successfully achieved by morphological transition engineering i.e. growth of nanoplates around the nanorods. Further, by suppression of intrinsic defect states during the growth of nanostructures, high UV to visible rejection ratio of <inline formula> <tex math notation=\"LaTeX\"$4.78\\times 10 {5} /tex math>/inline formula> and photoresponsivity of 578 A/W has been accomplished. The device has demonstrated high selectivity for UV A radiations, with a sharp responsivity peak at 350 nm of 60 nm FWHM. Moreover, the specific photo detectivity was calculated to be as high as <inline formula> <tex math notation=\"LaTeX\"$2.15\\times 10 \\mathbf {15} /tex math>/inline formula> cmHz<inline formula> <tex math notation=\"LaTeX\"{1/2}\\text{W} 1} /tex math>/inline formula> The proposed device has the capability to establish ZnO as a potential candidate for the variety of commercial applications, where high responsivity along with large UV to visible rejection ratio are the major requirements.",
"author_names": [
"Jitesh Agrawal",
"Tejendra Dixit",
"I A Palani",
"Vipul Singh"
],
"corpus_id": 226230392,
"doc_id": "226230392",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Highly Visible Blind ZnO Photodetector by Customizing Nanostructures With Controlled Defects",
"venue": "IEEE Photonics Technology Letters",
"year": 2020
},
{
"abstract": "Abstract Kinetically controlled growth of low dimensional zinc oxide (ZnO) nanostructures like nanorods, nanoflowers etc. have been demonstrated with enhanced photoluminescent emission by tuning of the hydroxide ion concentration in the precursor irrespective of the synthesis techniques. Change in concentration of the hydroxide ions in the precursor during the synthesis of ZnO nanostructured samples has been found to tune the aspect ratio of the nanostructures, viz. nanorods grown by electrodeposition, and morphology of nanoflowers to nanogranules synthesized by direct precipitation method. The photoluminescent emission from these samples has been found to increase synchronously with the increase in the concentration of hydroxide ions in the precursor. Observed enhancement in photoluminescence has been proposed to be due to the formation of superoxide O 2 charge transfer (CT) states C T O 2 due to the adsorption of molecular oxygen directly at grain boundaries or induced by hydroxide ions adsorbed over the surface of the nanostructures. The results are in contradiction to the established role of defect states behind photoluminescent emission from ZnO nanostructures. In this work, mathematical modelling has been used to establish the dominant role that superoxide CT states can play in enhancing the efficiency of ZnO based optoelectronic devices such as light emitting diodes and photodiodes.",
"author_names": [
"Dhritiman Banerjee",
"Asit Kumar Kar"
],
"corpus_id": 228865120,
"doc_id": "228865120",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Influence of oxygen related surface adsorbates on the growth of low dimensional nanostructures and enhanced luminescence due to superoxide charge transfer states in ZnO for application in optoelectronic devices",
"venue": "",
"year": 2020
},
{
"abstract": "Abstract The article reports a novel and highly efficient methodology for the development of surface defects free zinc oxide (ZnO) nanostructures, which are highly useful for various optoelectronic and electronic devices. Using this approach, we have developed high quality ZnO nanostructures with comparable physical and chemical properties to high temperature grown ones. Initially, ZnO nanostructures were developed by low temperature chemical bath deposition, and the surface defects passivated structures were obtained by atomic layer deposition of homo molecular clusters, i.e. Zn and O atomic layers. The surface passivated ZnO nanostructures exhibited excellent chemical stoichiometry between their constituents with enhanced crystalline quality. These nanostructures also showed improved light transmittance in the wavelengths range of 450 1000 nm, and light emission in the ultraviolet region. Further, the surface passivated nanostructures exhibited remarkable device performance as photoanodes with a greatly improved photocurrent density, more than 3 times, and reduced cathodic current of 6.17 x 10 7 A@ 0.4 V. Significantly, the light to dark current ratio of the PEC devices fabricated with passivated ZnO nanostructures is found to be 1761.",
"author_names": [
"Koteeswara Reddy Nandanapalli",
"Devika Mudusu",
"Sungwon Lee"
],
"corpus_id": 225473646,
"doc_id": "225473646",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Defects free single crystalline zinc oxide nanostructures for efficient photoelectrochemical solar hydrogen generation",
"venue": "",
"year": 2020
}
] |
synthesis, properties of semi conductor nano materials | [
{
"abstract": "Abstract The synthesis of CdS nano particles have been widely studied for their potential usage in the field of optics. The Semi conductor nanoparticles doped with transition metal ions have attracted a wide attention due to their excellent luminescent properties. The transition metal doped nano particles have different optical properties corresponding to their host counter parts. These nano particles have tremendous applications in the fabrication of optical light emitting diodes and to design a suitable window material in fabrication for solar cells. The microwave assisted solvothermal method is used to prepare the nano particles in this study. The nano structured materials of CdS were characterized by XRD and UV techniques. The size of the crystallite is determined by XRD to be 18.26 nm depending on the amount of the molar ratio of the reactants present in the sample. The nanocrystalline nature of CdS particles and the diffused pattern shows the presence of hexagonal phase in the present system. The quantum size dependent effect and the optical quality of the CdS and Mn doped CdS are studied. The optical absorption and transmitance spectrum of the Pure and Mn doped CdS nanocrystals are synthesized in this work. CdS is a commercially important II VI semiconductor having wide optical band gap, rendering it a very attractive material for optical application especially in nanocrystalline form. The UV absorption edge provides a reliable estimate of the band gap of any system. It is found that the band gap of the pure CdS nanosystem in the present study is 2.45 eV and this value is found to be larger than that of bulk CdS. This variation of the band gap may be useful to design a suitable window material in fabrication for solar cells. In optoelectronics, it finds use as light emitting diode, reflector, dielectric filter and window material.",
"author_names": [
"S Rinu Sam",
"Fergy John"
],
"corpus_id": 219044307,
"doc_id": "219044307",
"n_citations": 0,
"n_key_citations": 0,
"score": 1,
"title": "Optical properties of pure and doped CdS nanoparticles under solvothermal method",
"venue": "",
"year": 2020
},
{
"abstract": "The emerging need of CuS and Transition metal sulfides have numerous applications in various fields made its synthesis needful and meaning full. In recent years there is increasing interest in semiconductor nano crystals due to their novel physical and chemical properties. Most of these sulfides are crystalline and exhibit high lubricities. These features make these sulfides a far better photoluminescent material as compared to oxides. Many sulfides exhibit semi metallic behavior with respect to the ability to form multiple oxidation states, thus they are applicable in microelectronics as semiconductor materials.The emerging need of Cd and CdS nanoparticles in the medicine and many other fields made its synthesis needful and meaning full. For example CdS is an important semiconductor and has many optoelectronic applications including Solar cells, photodiodes, light emitting diodes, nonlinear optics and heterogeneous photo catalysis. In the present study we have synthesized CdS nanoparticles of chemical precipitation technique. CdS is an important inorganic material for light emitting applications. The literature survey showed that there are numerous methods to prepare Cadmium Sulfide (CdS) nanoparticles. To our knowledge, there is no report of synthesis of Cadmium sulfide nanoparticles by using SLS as a capping agent. So we have planned to synthesis the CdS nanoparticles by using SLS as a capping agent and to characterize the product by various analytical methods. Such The particles are characterized using FTIR, XRD, SEM, and Antimicrobial activity.",
"author_names": [
"S Priscilla Prabhavathi",
"",
"Shameela Rajam"
],
"corpus_id": 212518743,
"doc_id": "212518743",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "MICROWAVE SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL ACTIVITIES OF CuS AND CdS NANO PARTICLES",
"venue": "",
"year": 2014
},
{
"abstract": "Infra red (IR) luminescent quantum dots (QDs) are predominantly based on PbS or PbSe. However, while being attractive materials for solar energy conversion and photodetection, their long radiative lifetime and 8 fold degenerate HOMO and LUMO states make them less interesting for light emission applications. An alternative is offered by the mercury chalcogenides HgX (X=Se, Te) These materials are semi metals in the bulk, yet when the crystal dimensions are confined to nano scale regime, a band gap is opened up which can be tuned in the entire infra red range. While mainly studied in view of photodetection, the lower degeneracy of their band edge states and their shorter radiative lifetime as compared to PbS and PbSe makes them appealing for light emission too. A key step to make quantum dots fit for lighting application proved to be the formation of core shell QDs, where the shell provides a better surface passivation and allows for a further tuning of the opto electronic properties. However, while a broad range of shell growth procedures have been developed for Zn, Cd and Pb chalcogenide QDs, literature shows little examples of HgX based core/shell QDs of use of light emission applications. Here, we demonstrate the formation of HgSe/CdS and HgSe/CdSe core/shell QDs and report on the opto electronic properties of the materials thus formed. With lattice parameters of 0.608 (HgSe, CdSe) and 0.582 nm (CdS) and similar zinc blende crystal structures, CdSe and CdS are ideal shell materials to form HgSe based core/shell structures with minimal lattice strain. Considering the excessive ripening of HgSe QDs at typical shell growth temperatures, we developed a room temperature colloidal ALD procedure. As confirmed by electron microscopy, this results in the layer by layer growth of both CdSe and CdS around the HgSe core, with the QD diameter increasing by 0.6 nm per cycle. While growing up to 5 CdS and CdSe shells, we found that especially the first CdSe and CdS layers lead to a considerable redshift of the band edge transition and eliminate the n type doping of as synthesized HgSe QDs. This results in core/shell QDs showing bright photoluminescence in the near infrared, ranging from the telecom wavelengths of 1300 and 1550 nm to the longer wavelengths of interest for IR spectroscopy.",
"author_names": [
"Laxmi Chiluka",
"Pieter Geiregat",
"Willem Walravens",
"Zeger Hens"
],
"corpus_id": 137905361,
"doc_id": "137905361",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Synthesis of novel HgSe/CdS and HgSe/CdSe core shell nanocrystals by C ALD approach in the infra red",
"venue": "",
"year": 2015
},
{
"abstract": "For the past few years, the prepration and characterization of nanocrystals of materials have become an interesting area in the research activity. CdS (Cadmium Sulphide) is a well known semi conducting material which finds applications in optical devices. In the present study, we have made an attempt to investigate the effect of Pb as impurity on the properties of CdS nanocrystals. The samples were prepared by using simple domestic microwave assisted solvothermal method with ethylene glycol as solvant. The samples prepared were annealed to have good ordering. X ray diffraction measurements were carried out for all the smples. The grain size, lattice parameter and yield were determined. The colour before and after annealing was noted. EDX and SEM analyses were also done. The prepared samples were electrically characterized by making dielectric measurements on the prepared pellets. The present study indicates that the polarization mechanism in the nano crystals considered is mainly contributed by the space charge polarization.",
"author_names": [
"K U Madhu"
],
"corpus_id": 138037565,
"doc_id": "138037565",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF CDS NANOCRYSTALS ADDED WITH PB2",
"venue": "",
"year": 2013
},
{
"abstract": "Abstract The article describes the synthesis of solid solutions of ZnS CdSe, ZnS CdS, ZnS ZnTe systems (for the first time in the given compositions) Through X ray, IR spectroscopic and electron microscopic studies, the findings about their bulk physicochemical properties were obtained. These data can be used for certification and determination of their structures. It was determined that solid substitution solutions with preliminary hexagonal structures are formed. According to the results of the acid base properties investigation, the surfaces of all stated systems components exposed to air have slightly acid nature and offer the increased activity against the basic gases. Generally, the coordinatively unsaturated atoms account for the surfaces acidity. The interrelated laws were found in changing of the acid base and most essential bulk physicochemical properties on modifying the composition of the series of analogues ZnBIV, CdBIV and the solid substitution solutions formed by them. These laws likely connected to the electron structure of the non metallic components are used to find the most active adsorbents, primary transducer materials of the sensors for basic gases micro impurities.",
"author_names": [
"I A Kirovskaya",
"Ekaterina Mironova",
"V E Leonov",
"B A Kosarev",
"A A Grigan",
"A V Yureva"
],
"corpus_id": 93126517,
"doc_id": "93126517",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "The activity of new materials surfaces ternary semi conductors with cationic and anionic substitution",
"venue": "",
"year": 2015
},
{
"abstract": "Abstract In the present contribution a simplistic synthesis of SnO 2 thin film on ultrasonically cleaned soda lime glass is outlined. Precursor solution of strength 0.1 M, 0.2 M and 0.3 M are used for the synthesis using a homemade affordable spray pyrolysis technique. An elaborate structural analysis is carried from the X Ray diffraction data. The structural analysis is supported by the transmission electron microscopy micrograph and selected area electron diffraction pattern. The crystallite sizes are below 50 nm that makes the films suitable for nano material application. Formation of texture is observed which indicates the preferred orientation to be the (101) plane. In comparison to techniques like pulsed laser deposition, spray pyrolysis provides better results for certain applications. The morphology of the thin films is investigated using atomic force microscopy. It revealed the control of application dependent roughness of the sample by variation of molarity of the precursor solution. Also the film is uniformly spread throughout the substrate. The optical properties are studied by UV Visible spectroscopy that further confirms formation of nano structures. Preliminary electrical investigation of the thin films is done by using a two probe semi conductor characterization system and is correlated with UV Visible result. Impedance analysis showed that with higher molarity the impedance remains constant and the barrier height remains fixed for high frequency which predicts that the films can be used for rectifying applications.",
"author_names": [
"Sandip Paul Choudhury",
"Sneha Gunjal",
"Navnita Kumari",
"Kiran Diwate",
"Kakasaheb C Mohite",
"Ayon Bhattacharjee"
],
"corpus_id": 139057450,
"doc_id": "139057450",
"n_citations": 15,
"n_key_citations": 0,
"score": 0,
"title": "Facile synthesis of SnO2 thin film by spray pyrolysis technique, investigation of the structural, optical, electrical properties",
"venue": "",
"year": 2016
},
{
"abstract": "Silver tellurides are found as minerals like hessite (Ag2Te) and empressite (AgTe) They possess interesting physical properties including transition from semi to ionic conductor character and large magnetoresistance in non stoichiometric compounds. Silver tellurides exhibit high electron mobility and low thermal conductivity which are desirable for thermo electronics, finding applications in infrared detection, imaging, magnetics, sensors, memory devices and optic materials. Laser desorption ionisation time of flight mass spectrometry (LDI TOF MS) is powerful technique to follow the generation of clusters from various solid materials. In this work new nano composite consisting of nano silver and tellurium has been prepared and characterized by XPS, SEM, AFM, etc. The use of this material for surface enhanced Raman resonance scattering (SERRS) was evaluated. Furthermore, the nano composite was used as a precursor for laser ablation synthesis (LAS) of novel AgpTeq clusters analysed by TOF MS. In addition, oxygenated silver tellurium clusters with general formula AgpTeqOr were also detected. Stoichiometry of all generated clusters was determined via computer modeling. On the basis of new structural silver tellurium motifs novel high tech materials are proposed.",
"author_names": [
"Filippo Amato",
"Ravi Madhukar Mawale",
"Milan Alberti",
"Josef Havel"
],
"corpus_id": 136214224,
"doc_id": "136214224",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Generation of mixed AgpTeq clusters via laser ablationsynthesis using novel Ag Te nano composite as precursor.Time of flight mass spectrometric study",
"venue": "",
"year": 2014
},
{
"abstract": "Since their discovery in 2004, carbon dots have emerged out as a new class of material with a number of attractive physicochemical properties like fluorescence fair water solubility non toxicity, biocompatibility, chemical stability etc. Owing to these excellent properties, carbon dots (CDs) have potential to be used in bio imaging bio sensing, drug delivery catalysis etc. Recently, we have reported water absorption and moisture permeation behavior of chitosan/carbon dot Nano composite films and observed that carbon dots act as an effective cross linker due to electrostatic interactions between negatively charged carboxylate groups on the surface of carbon dot and positively charged NH3+ groups along the protonated chitosan chains. It was observed that water absorption of chitosan/carbon dots nanocomposite films decreased many folds as compared to the plain chitosan films. This led us to believe that incorporation of carbon dots into drug loaded chitosan film could bring about a desirable release of entrapped bioactive ingredient in a controlled manner. Chitosan is a semi synthetic polymer, obtained from a controlled de acetylation of chitin .Because of excellent biocompatibility; chitosan has a wide range of biomedical applications. Since carbon dot also possess fair biocompatibility, a combination of pre calculated quantities of chitosan and carbon dot could serve as an effective dressing material to offer a controlled release of drug in wound healing management. In the present work, we have prepared carbon dots from 1, 2, 3, 4 Butane tetra carboxylic acid via microwave synthesis approach. The CD, so prepared, had their surface covered with COOH groups. Then we entrapped these functionalized CD along with model antibacterial drug Oxy tetracycline (OTC) in chitosan film by solution casting method. The release of drug OTC from the film matrix could be regulated by varying the CD concentration within the film matrix as CD provided physical crosslinking to the chitosan network. Therefore, variation in the CD contents within the film matrix could regulate the release rate of OTC. In this way, without using toxic chemical crosslinking agents, a controlled release of OTC from chitosan films could be achieved.",
"author_names": [
"Katta Eswar Srikanth"
],
"corpus_id": 229198361,
"doc_id": "229198361",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Oxytetracycline Drug Release Behavior",
"venue": "",
"year": 2020
},
{
"abstract": "Zinc oxide (ZnO) has a wurtzite structure, a characteristic of semi conductors, and is used in electronic ceramic devices [1, 2] and photo catalysts [3, 4] Nanoscale particles possess different physical and chemical properties compared to bulk materials. Better sinterability, higher catalytic activity, and other unique properties may be expected because of their nano sized crystallite, large surface area and different surface properties (such as surface defect) etc. At present, two methods are generally being used to obtain nanosized ZnO powder: vapor method and sol gel method, which require high processing and chemicals costs, respectively [5] Therefore, the synthesis method of nano sized ZnO powders can still be improved. Recently, several researchers proposed the solution combustion method to synthesize simple and mixed metal oxides [6 11] Using this method, the heating and evaporation of metal nitrate solution with an organic compound (such as glycine, urea, or citric acid etc. results in self firing and generates intense heat by exothermic reaction. This intense heat is used to synthesize the ceramic powders. This novel approach has the advantages of inexpensive raw materials, a relatively simple preparation process, and a fine resulting powder with high homogeneity. Although there is little literature reporting that nanosized ZnO have been synthesized by this method [4, 5, 12, 13] there is also hardly any information available on the effects of reactant composition in the nature of combustion reaction phenomena on the properties of as synthesized ZnO powders. In this work, the study of correlation among reactant composition, reaction phenomena, and product characteristics are undertaken. Glycine (NH2CH2COOH) was selected as the fuel since it is inexpensive and its combustion heat 3.24 Kcal/g) is more negative when compared with urea 2.98 Kcal/g) or citric acid 2.76 Kcal/g) On the other hand, zinc nitrate [Zn(NO3)2*6H2O] is utilized in the present work because of its dual role of being the zinc source and the oxidant. The combustion reaction can be expressed (but over simplified) as follows:",
"author_names": [
"Chyi-Ching Hwang",
"Tsung-Yung Wu"
],
"corpus_id": 95035876,
"doc_id": "95035876",
"n_citations": 47,
"n_key_citations": 1,
"score": 0,
"title": "Combustion synthesis of nanocrystalline ZnO powders using zinc nitrate and glycine as reactants influence of reactant composition",
"venue": "",
"year": 2004
},
{
"abstract": "Abstract The present work describes the realization of inorganic semi conducting compounds in the form of a monomolecular plane, generated from an L.B. matrix. Mercury and cadmium sulfides are obtained by a two step, in situ synthesis, from the organic molecules of an L.B. film: multilayers of behenic acid are transformed into cadmium or mercury behenate by an aqueous diffusion of each ion. Next, a gaseous diffusion of hydrogen sulfide precipitates the HgS or CdS in the polar plane with regeneration of the behenic acid matrix. These chemical reactions are followed by infrared spectroscopy. The observed photoelectric properties in the near U.V. range argues in favour of a) a monomolecular plane of a semiconducting sulfide. b) a 2D structure of the sulfides, different from the known 3D crystals of HgS and CdS which absorb in the visible and infrared range. Hence it can be assumed that the 2D sulfide synthesis is matrix controlled, since the physical properties are different. This opens the field for new monomolecular materials because this experiment can be enlarged to other compounds.",
"author_names": [
"Cecile Zylberajch",
"Annie Ruaudel-Teixier",
"Andre Barraud"
],
"corpus_id": 94226358,
"doc_id": "94226358",
"n_citations": 23,
"n_key_citations": 0,
"score": 0,
"title": "2D monomolecular inorganic semi conductors, inserted in a Langmuir Blodgett matrix",
"venue": "",
"year": 1988
}
] |
polarization based mzi | [
{
"abstract": "In this paper, the all optical up and down wavelength converter based on cross polarization modulation (XPolM) effect in semiconductor optical amplifier Mach Zehnder Interferometer (SOA MZI) has been proposed and evaluated for error free operation to show the feasibility of 40 Gbps differential phase shift keying modulated data signal. The wavelength conversion is achieved by rotational state of polarization of pump and probe signal in SOA. Also, investigation of wavelength converter is theoretically and analytically validated for optimum performance and investigation results show good agreement with each other. The impact of variable signal power along with different parameter of SOA on performance of converted wavelength signal in terms of optical received power and Q factor has been given. The investigations revealed that wavelength converter based on XPolM effect in SOA MZI can be the promising option to enhance the expandability and accessibility of future hybrid optical access networks.",
"author_names": [
"Sukhbir Singh",
"Surinder Singh"
],
"corpus_id": 213921104,
"doc_id": "213921104",
"n_citations": 0,
"n_key_citations": 0,
"score": 1,
"title": "Design of optical wavelength conversion based on cross polarization modulation effect of SOA MZI",
"venue": "",
"year": 2020
},
{
"abstract": "We have experimentally demonstrated an O band Mach Zehnder interferometer (MZI) based on an N rich silicon nitride platform combined with Ge 2 Sb 2 Te 5 for future optical communication applications. The device operation relies on controlling the waveguide's losses using a phase change material cell, which can be changed from amorphous (low loss) to crystalline (high loss) An extinction ratio as high as 11 dB was obtained between the amorphous (ON) and the crystalline (OFF) states of the MZI optical building block. The insertion loss of the MZI structure per cell unit length was measured to be as high as 0.87 dB/mm in the OFF state and as low as 0.064 dB/mm in the ON state for TM polarization.",
"author_names": [
"Joaquin Faneca",
"Thalia Dominguez Bucio",
"Frederic Y Gardes",
"Anna Baldycheva"
],
"corpus_id": 216327488,
"doc_id": "216327488",
"n_citations": 8,
"n_key_citations": 0,
"score": 0,
"title": "O band N rich silicon nitride MZI based on GST",
"venue": "",
"year": 2020
},
{
"abstract": "Abstract A high sensitivity optical fiber temperature sensor based on the Vernier effect of cascaded fiber Sagnac interferometer (FSI) and Mach Zehnder interferometer (MZI) is proposed and experimentally demonstrated. The FSI is composed of a 3 dB four port coupler and a section of polarization maintaining fiber, which has high sensitivity and good stability as the sensing part. As the filtering part, MZI is made up of two three port couplers by controlling the length of the two arms. The free spectral range (FSR) of these two interferometers is similar but not equal, so the cascade system can effectively amplify the temperature sensing sensitivity based on the vernier effect. The experimental results show that the temperature sensitivity of a single FSI is only 1.68 nm/degC, and the cascade system can amplify it to 14.30 nm/degC with a gain coefficient of 8.51, which is consistent with the theoretical results.",
"author_names": [
"Meihua Bi",
"Yang Guowei"
],
"corpus_id": 237663511,
"doc_id": "237663511",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "High sensitivity optical fiber temperature sensor of cascaded FSI and MZI based on Vernier effect",
"venue": "",
"year": 2021
},
{
"abstract": "We propose a large aperture static imaging spectrometer (LASIS) based on planar lightwave circuit (PLC) MZI array. The imaging spectrometer works in the push broom mode with the spectrum performed by interferometry. While the satellite/aircraft is orbiting, the same source, seen from the satellite/aircraft, moves across the aperture and enters different MZIs, while adjacent sources enter adjacent MZIs at the same time. The on chip spectrometer consists of 256 input mode converters, followed by 256 MZIs with linearly increasing optical path delays and a detector array. Multiple chips are stick together to form the 2D image surface and receive light from the imaging lens. Two MZI arrays are proposed, one works in wavelength ranging from 500nm to 900nm with SiON(refractive index 1.6) waveguides and another ranging from 1100nm to 1700nm with SOI platform. To meet the requirements of imaging spectrometer applications, we choose large cross section ridge waveguide to achieve polarization insensitive, maintain single mode propagation in broad spectrum and increase production tolerance. The SiON on chip spectrometer has a spectral resolution of 80cm 1 with a footprint of 17x15mm2 and the SOI based on chip spectrometer has a resolution of 38cm 1 with a size of 22x19mm2. The spectral and space resolution of the imaging spectrometer can be further improved by simply adding more MZIs. The on chip waveguide MZI array based Fourier transform imaging spectrometer can provide a highly compact solution for remote sensing on unmanned aerial vehicles or satellites with advantages of small size, light weight, no moving parts and large input aperture.",
"author_names": [
"Minyue Yang",
"Mingyu Li",
"Jian-jun He"
],
"corpus_id": 113639608,
"doc_id": "113639608",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Push broom imaging spectrometer based on planar lightwave circuit MZI array",
"venue": "Commercial Scientific Sensing and Imaging",
"year": 2017
},
{
"abstract": "In this paper, a new all optical flip flop structure based on semiconductor optical amplifier (SOA) and Mach Zehnder interferometer (MZI) is presented and demonstrated. Through carrying out a detailed analysis of SOA's NPR effect and the coupled SOA MZI structure, we build up a theoretical SOA model with polarization dependent rate equations and MZI model employing SOA cross phase modulation in the scheme. We will implement four kinds of clocked flip flop, including D SR T and JK types. Each type has its own logic circuit and working principle. We demonstrate the effectiveness of proposed programs by showing the extinction ratio and state switching speed. The state switching speed includes the rising and falling edges triggering times. In the experiment, to facilitate analysis, the clock pulse repetition frequency is 1 GHz, the rising edge transition time can decrease to less than 50 ps and the extinction ratio is about 30 dB.",
"author_names": [
"Lina Wang",
"Yongjun Wang",
"Shuai Wang",
"Yichuan Geng",
"Mingxia Zhang"
],
"corpus_id": 20144441,
"doc_id": "20144441",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "All optical Flip flop Based on SOA and MZI switch",
"venue": "2016 Progress in Electromagnetic Research Symposium (PIERS)",
"year": 2016
},
{
"abstract": "Multimode based polarization independent (PI) wavelength division multiplexing (WDM) devices are proposed and experimentally demonstrated. The key concept is to utilize two different order modes for the orthogonal polarizations, ith order mode for TE and jth order mode for TM (i j) polarization respectively to extend the flexibility for designing devices. PI coupler composed of a multimode directional coupler and mode converters is introduced as a basic device. Then, we apply PI coupler to Mach Zehnder interferometer (MZI) and Bragg grating bandpass filters. PI MZI is achieved by optimizing the combination of two phase shifters in the interferometer arms. PI bandpass uses 3dB PI coupler and polarization rotate Bragg gratings that induce mode coupling between the polarizations. Each device showed good matching in the spectrum between TE and TM polarizations in term of operation wavelength. The proposed concept can be a promising approach to realize PI WDM functions without introducing polarization diversity scheme in which a polarization beam splitter, two devices designed for each polarization and a polarization beam combiner are required.",
"author_names": [
"Yosuke Onawa",
"Hideaki Okayama",
"Daisuke Shimura",
"Hiroki Yaegashi",
"Hironori Sasaki",
"Masayuki Kashima"
],
"corpus_id": 229439585,
"doc_id": "229439585",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Multimode based polarization independent WDM devices using different order modes for TE and TM polarizations.",
"venue": "Optics express",
"year": 2020
},
{
"abstract": "High performance InP based polarization beam splitters (PBSs) with a symmetrical Mach Zehnder interferometer (MZI) are theoretically and experimentally demonstrated. The p i n waveguide is exploited to employ the phase shifters in the two arms of the MZI. Injection current and reverse bias inducing electro optic (EO) effects in each of the MZI arms are analysed in detail when the waveguides are aligned along both the [011] and <inline formula><tex math notation=\"LaTeX\" {01\\bar{1} /tex math>/inline formula> directions. Results indicate that the birefringence from reverse bias help to realize the PBS combining with the polarization independent carrier induced refractive index change from the injection current. Theoretical prediction shows that the polarization extinction ratio (PER) is over 35 dB at 1550 nm for the PBSs with the waveguides aligned along both directions. Furthermore, the PBS with the waveguides aligned along the [011] direction can be adjusted more easily to work at the best operating point and get the higher birefringence which requires lower reverse bias exhibiting better performance across the C band compared with the <inline formula><tex math notation=\"LaTeX\" {01\\bar{1} /tex math>/inline formula> direction. The fabricated PBSs exhibit a PER over 19 dB (14 dB) in the wavelength range from 1525 to 1570 nm with one arm injected of 2.88 mA (0.2 mA) current and the other arm reversed biased at 5.63 V (7.89 V) when the waveguides aligned along the [011] <inline formula><tex math notation=\"LaTeX\" {01\\bar{1} /tex math>/inline formula> direction. The PER of both PBSs is expected to be 20 dB across the C band with the help of a birefringence contribution arising from inserting waveguide arms of different widths.",
"author_names": [
"Xiangyang Dai",
"Quanan Chen",
"Gongyuan Zhao",
"Yuanyuan Liu",
"Qiaoyin Lu",
"John F Donegan",
"Weihua Guo"
],
"corpus_id": 214421575,
"doc_id": "214421575",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "High Performance InP Based Polarization Beam Splitter With Reverse Bias and Injection Current",
"venue": "Journal of Lightwave Technology",
"year": 2020
},
{
"abstract": "Designing the photonics integrated circuit on silicon platform is a challenging task. For most of the photonic devices interferometers acts as major foundational block. One of the famous interferometer in photonics design is called as Mach Zehender Interferometer(MZI).This paper explains design simulation, fabraction and measurement of fabricated MZI device. The wavelength range has been chosen to be TE polarization 1500 1600 nm with waveguide being strip waveguide. Such five MZI devices have been designed with variation in waveguide length and simulation was performed over larger number of data points. The design have been simulated in software Lumerical mode and Lumerical Interconnect. Based on the simulation the mask layout was prepared for fabrication using tool called KLayout. The complete layout was fabricated over a footprint of 605mm x 410mm at Applied Nanotools Inc. Canada and Washington Nanofabrication Facility USA. The measurement of the fabricated devices have been performed and compared with simulated device.",
"author_names": [
"Yashodhan Mandke",
"Arunagiri Sivasubramanian",
"Rabinder Henry"
],
"corpus_id": 212702753,
"doc_id": "212702753",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Design, Fabrication and characterisation of TE Mode MZI Device for Silicon Photonics Integrated Circuit",
"venue": "2019 IEEE 5th International Conference for Convergence in Technology (I2CT)",
"year": 2019
},
{
"abstract": "Large scale optical switching matrix is the core technology of automatically switched optical network. With the significant increase of the matrix size, the study showed that the nonlinear factors, such as the correlation of the wavelength, phase and polarization between the optical switches have major impacts for the system performance. Because the full size optical simulation is not available now, the research will be a great significance that we establish an overall model with not only considering the performance of optical switch unit, but also reflecting the structural characteristics of the network.In this paper, we calculated the transmission field of 2x2 Mach Zehnder(MZI) silica on silicon thermo optic(TO) switch with different structure by using the finite difference beam propagation method(BPM) On the basis of optimization design, we constructed and simulated the large scale 16x16 MZI silicon based SiO2 Silica on silicon thermo switching matrix. The results are: In TE Mode, for Crossbar and banyan structures, insertion losses are 13.35 dB and 4.3638 dB; crosstalk losses are 27.125~29.0173 dB and 42.2318 43.7159 dB; extinction ratios are 29.57 dB and 26.79 dB respectively.",
"author_names": [
"Lijun Guo",
"Tian-Xiong Wang",
"Lin Qi"
],
"corpus_id": 210130748,
"doc_id": "210130748",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Optimal design for large scale MZI silica on silicon optical thermo switching matrix",
"venue": "Other Conferences",
"year": 2019
},
{
"abstract": "A multiwavelength erbium doped fiber laser based on a polarization dependent in line Mach Zehnder Interferometer (in line MZI) is proposed and experimental demonstrated. The polarization dependent in line MZI demonstrated is constructed by sandwiching a length of polarization maintaining fiber (PMF) between two abrupt fiber tapers fabricated in SMF. The proposed in line MZI can work as a cost effective all fiber based polarizer. In combination with the nonlinear polarization rotation technique, stable multiwavelength laser comb with uniform wavelength spacing is achieved at room temperature. The wavelength spacing is 0.8 nm. By properly tuning the PCs, the output laser combs with double and triple channel spacing can be also obtained.",
"author_names": [
"Wanjing Peng",
"Peng Liu"
],
"corpus_id": 202936748,
"doc_id": "202936748",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Multiwavelength erbium doped fiber laser based on a polarization dependent in line Mach Zehnder interferometer",
"venue": "Optical and Quantum Electronics",
"year": 2019
}
] |
High step-up dc–dc converter based on modified active switched-inductor and switched-capacitor cells | [
{
"abstract": "A new high gain step up dc dc converter based on modified active switched inductor (MASL) and switched capacitor (SC) is proposed in this study. The proposed converter is based on the classical boost topology, in which the inductor is changed by the proposed MASL cell. This new cell allows the addition of more than two switched inductors (SLs) to the classical boost topology, which is the most significant limitation of conventional active SL. Additionally, in the proposed converter, the output capacitor is replaced by an SC cell, increasing still more the voltage gain of it, which can be higher than 20 without using transformers or coupled inductors, and with lower voltage stress on the semiconductors and high efficiency. The principle of operation, theoretical static and dynamic analysis, design methodology and comparison with other non isolated topologies present in the literature are approached in this study. The performance of the proposed converter is validated by interesting experimental results obtained from a 200 W prototype with an input voltage of 20 V, an output voltage of 400 600 V, switched frequency at 50 kHz and peak efficiency of 95%",
"author_names": [
"Jessika Melo de Andrade",
"Roberto Francisco Coelho",
"Telles Brunelli Lazzarin"
],
"corpus_id": 225754539,
"doc_id": "225754539",
"n_citations": 2,
"n_key_citations": 0,
"score": 1,
"title": "High step up dc dc converter based on modified active switched inductor and switched capacitor cells",
"venue": "",
"year": 2020
},
{
"abstract": "In this paper, a high step up dc dc converter is proposed. The main feature of the proposed converter is its flexibility in developing and achieving different high voltage gains. This converter comprises of inductor capacitor cells and with a higher number of cells, voltage gain increases. The proposed converter's operation principle is based on charging in parallel and discharging in series paths. Operation analysis and voltage gain and voltage stresses of semiconductors are calculated and contrasted with other converters to illustrate the prominent attributes of the proposed converter. Simulation results, which have been implemented via PSCAD EMTDC, are presented to validate the performance of this converter.",
"author_names": [
"Sama Salehi",
"Neda Zahedi",
"Reza Kheirollahi",
"Ebrahim Babaei"
],
"corpus_id": 133605696,
"doc_id": "133605696",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Ultra High Step up DC DC Converter Based on Switched Inductor Capacitor Cells",
"venue": "2019 10th International Power Electronics, Drive Systems and Technologies Conference (PEDSTC)",
"year": 2019
},
{
"abstract": "In this paper, a novel high step up dc/dc converter is presented for renewable energy applications. The suggested structure consists of a coupled inductor and two voltage multiplier cells, in order to obtain high step up voltage gain. In addition, two capacitors are charged during the switch off period, using the energy stored in the coupled inductor which increases the voltage transfer gain. The energy stored in the leakage inductance is recycled with the use of a passive clamp circuit. The voltage stress on the main power switch is also reduced in the proposed topology. Therefore, a main power switch with low resistance RDS (ON) can be used to reduce the conduction losses. The operation principle and the steady state analyses are discussed thoroughly. To verify the performance of the presented converter, a 300 W laboratory prototype circuit is implemented. The results validate the theoretical analyses and the practicability of the presented high step up converter.",
"author_names": [
"Ali Ajami",
"Hossein Ardi",
"Amir Farakhor"
],
"corpus_id": 21552982,
"doc_id": "21552982",
"n_citations": 241,
"n_key_citations": 7,
"score": 0,
"title": "A Novel High Step up DC/DC Converter Based on Integrating Coupled Inductor and Switched Capacitor Techniques for Renewable Energy Applications",
"venue": "IEEE Transactions on Power Electronics",
"year": 2015
},
{
"abstract": "For a variety of renewable energy applications, large number of dc dc converters can be used. Here a high step up dc dc converter using a integrated coupled inductor and switched capacitor is proposed. The converter acheives high voltage gain with the help of an inductor which is coupled type and two voltage multiplier cells. When the switch is off the two capacitors are charged using the energy in the inductor which is coupled type, leading to an increase in the voltage gain. Recycling of the energy in the leakage inductance by the passive clamp circuit leads to decrease in the switching stresses.",
"author_names": [
"M Vinduja",
"Aswin T Surendran",
"M Madhu"
],
"corpus_id": 49186371,
"doc_id": "49186371",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "A high step up DC DC converter based on integrated coupled inductor and switched capacitor",
"venue": "2018 International Conference on Power, Signals, Control and Computation (EPSCICON)",
"year": 2018
},
{
"abstract": "This paper proposes a high voltage gain dc/dc converter with coupled inductor cells and switched capacitor for renewable energy applications. It includes coupled inductor, switched capacitor and voltage multiplier cell. Switched capacitor charged during off period by using the energy stored in the coupled inductor. This will increase the performance of the converter. The operation principle and steady state analyses are discussed thoroughly. Simulation is done with 40V input voltage, 300W output power and 400V output voltage using MATLAB.",
"author_names": [
"Josie Baby",
"Della David"
],
"corpus_id": 64009818,
"doc_id": "64009818",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "CLOSED LOOP CONTROL OF HIGH STEP UP DC/DC CONVERTER BASED ON COUPLED INDUCTOR AND SWITCHED CAPACITOR",
"venue": "",
"year": 2015
},
{
"abstract": "Nowadays, with the high power demand in industries, the need for high step up converters has been a crucial part of interest. Power conservation is an essential aspect of innovation leading to improving the voltage gain of conventional converters such as boost, Cuk and SEPIC. Boosting techniques including voltage multiplier (VM) cells, voltage lift capacitors, coupled inductors, switched capacitor/inductor, etc. are used to enhance the conventional converters to meet high voltage requirements of various applications. This paper proposes a new high voltage gain DC DC converter using a coupled inductor and VM cell. The operation of the converter is based on charging the capacitor using a single MOSFET switch and adding it in series with the source to the load. Besides, a passive clamp circuit which is comprised of capacitor and diode has been selected over the active clamp to reduce the voltage stress on the MOSFET switch, which helps to improve the voltage gain of the converter. The turns ratio of the coupled inductor is chosen appropriately to get the required voltage gain. Reduction in voltage stress results in selecting MOSFET with small on state resistance R ds on which offers less conduction loss and high efficiency of the converter. The proposed converter is modeled, analyzed and simulated using PLECS simulation software. The results are experimentally verified by developing 150 W experimental prototype.",
"author_names": [
"Manoharan Premkumar",
"C Kumar",
"A Anbarasan",
"Ravichandran Sowmya"
],
"corpus_id": 212783877,
"doc_id": "212783877",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "A novel non isolated high step up DC DC boost converter using single switch for renewable energy systems",
"venue": "",
"year": 2020
},
{
"abstract": "This study proposes a series of high step up DC/DC converters based on the coupled inductor and switched capacitors. The priority of the switched capacitor connection methods of the converters is presented by their contributions to the voltage gain so that the converters can be selected optimally according to the gain demand. For this converter, the voltage gain can be adjusted by both of the turns ratios of the coupled inductor and the number of switched capacitor units. It makes it possible to further improve the voltage gain when the turns ratio of the coupled inductor is rather high. Moreover, the introduction of switched capacitors can reduce the voltage stress of power components. In this study, the operating principle and performance characteristics of the converters are analysed. Also, a 300 W prototype is set up for verification. The experimental results demonstrate the effect of the theoretical analysis and superiority of the converter.",
"author_names": [
"Jie Ding",
"Shi Wei Zhao",
"Huajie Yin",
"Ping Qin",
"Guanbao Zeng"
],
"corpus_id": 225674462,
"doc_id": "225674462",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "High step up DC/DC converters based on coupled inductor and switched capacitors",
"venue": "",
"year": 2020
},
{
"abstract": "This paper presents renewable energy system which consists of low voltage sources like fuel cells and photovoltaic (PV) cells. Thus the high step up dc dc converters are used to produce high step up gain. Theoretically the boost converter can provide the high voltage gain at large duty cycle. But in practice the voltage gain is reduced, due to losses in utilized components like rectifier diode, power switch, inductor and capacitor. Hence the converter using coupled inductor technique was introduced. However, the leakage inductor cause voltage transients on main switch and also reduce the conversion efficiency. To mitigate the voltage stress on the main switch due to voltage spike/transients, the coupled inductor with active clamp circuit based converters are introduced. In this work, a high step up dc dc converter with lossless passive clamp circuit is proposed to reduce stress on the main switch and also to recycle the energy of the leakage inductor. The proposed topology consists of two diodes and two capacitors on the secondary side of the coupled inductor to achieve the high voltage gain. The proposed topology will be analysed in PSIM model in both continuous conduction mode (CCM) and discontinuous conduction mode (DCM) of operation and the boundary condition between CCM and DCM will be presented.",
"author_names": [
"A Suganya",
"M Sudhakaran"
],
"corpus_id": 16831366,
"doc_id": "16831366",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Performance analysis of high step up DC DC converter for photovoltaic (PV) system",
"venue": "2015 International Conference on Circuits, Power and Computing Technologies [ICCPCT 2015]",
"year": 2015
},
{
"abstract": "High step up voltage gain dc/dc converters are widely used in renewable energy power generation, uninterruptible power system, etc. In order to avoid the influence of leakage inductor in coupled inductors based converters, switched inductor boost converter (SL boost) switched capacitor boost converter (SC boost) and active network converter (ANC) have been developed. With the transition in series and parallel connection of the inductors and capacitors, high step up voltage conversion ratio can be achieved. This paper discusses the characteristics of the switched inductor and switched capacitor cell; makes some comparisons between the ANC and boost converter. Based on the aforementioned analysis, this paper proposed the multicell switched inductor/ switched capacitor combined active network converters (MSL/SC ANC) The proposed converters combine the advantages of SL/SC unit and active network structure. Compared with previous high step up converters, the novel converter provides a higher voltage conversion ratio with a lower voltage/current stress on the power devices, moreover, the structure of proposed SL/SC ANC is very flexible, which means the quantity of SL and SC cells can be adjusted according to required voltage gain. A 20 times gain prototype is designed as an example to show the design procedure. Theoretical analysis and experimental results are presented to demonstrate the feature of the proposed converter.",
"author_names": [
"Yu Tang",
"Ting Wang",
"Dongjin Fu"
],
"corpus_id": 27410060,
"doc_id": "27410060",
"n_citations": 92,
"n_key_citations": 3,
"score": 0,
"title": "Multicell Switched Inductor/Switched Capacitor Combined Active Network Converters",
"venue": "IEEE Transactions on Power Electronics",
"year": 2015
},
{
"abstract": "High step up voltage gain DC/DC converters are widely used in renewable energy power generation, uninterruptible power system, etc. In order to avoid the influence of leakage inductor in coupled inductors based converters, switched inductor Boost converter (SL Boost) switched capacitor Boost converter (SC Boost) and active network converter (ANC) have been developed. With the transition in series and parallel connection of the inductors and capacitors, high step up voltage conversion ratio can be achieved. This paper discusses the characteristics of the switched inductor (SL) and switched capacitor (SC) cell and makes some comparisons between the ANC and Boost converter. Based on the above analysis, this paper proposed the multicell switched inductor/switched capacitor combined active network converters (MSL/SC ANC) The proposed converters combine the advantages of SL/SC unit and active network structure. Compared with previous high step up converters, the novel converter provides a higher voltage conversion ratio with a lower voltage/current stress on the power devices. Moreover, the structure of proposed SL/SC ANC is very flexible, which means the quantity of SL and SC cells can be adjusted according to required voltage gain. A 20 times voltage gain prototype is designed as an example to show the design procedure. Theoretical analysis and experimental results are presented to demonstrate the feature of the proposed converter.",
"author_names": [
"Yaohua He",
"Yu Tang",
"Ting Wang",
"Dongjin Fu"
],
"corpus_id": 17934946,
"doc_id": "17934946",
"n_citations": 4,
"n_key_citations": 1,
"score": 0,
"title": "Switched inductor/switched capacitor active network converters",
"venue": "2014 9th IEEE Conference on Industrial Electronics and Applications",
"year": 2014
}
] |
Laser ablation method | [
{
"abstract": "A method combining laser ablation cluster formation and vapor liquid solid (VLS) growth was developed for the synthesis of semiconductor nanowires. In this process, laser ablation was used to prepare nanometer diameter catalyst clusters that define the size of wires produced by VLS growth. This approach was used to prepare bulk quantities of uniform single crystal silicon and germanium nanowires with diameters of 6 to 20 and 3 to 9 nanometers, respectively, and lengths ranging from 1 to 30 micrometers. Studies carried out with different conditions and catalyst materials confirmed the central details of the growth mechanism and suggest that well established phase diagrams can be used to predict rationally catalyst materials and growth conditions for the preparation of nanowires.",
"author_names": [
""
],
"corpus_id": 10392634,
"doc_id": "10392634",
"n_citations": 3681,
"n_key_citations": 20,
"score": 1,
"title": "A laser ablation method for the synthesis of crystalline semiconductor nanowires",
"venue": "Science",
"year": 1998
},
{
"abstract": "Abstract Pulsed laser ablation in liquid is an approach for micro /nanostructure generation directly from bulk materials. It has grown rapidly as a research field of photochemistry and physical chemistry in the last decade, and represents a combinatorial library of constituents and interactions, but the understanding of this library is still insufficient. This review attempts to build up a comprehensive mechanistic scenario of pulsed laser ablation in liquid and illustrate the underlying principles to micro /nanostructure generation. Various structures produced by this method have been summarized that provide prototypes for potential applications in sensing, optoelectronics, and biomedicine, etc.",
"author_names": [
"Zijie Yan",
"Douglas B Chrisey"
],
"corpus_id": 95094854,
"doc_id": "95094854",
"n_citations": 230,
"n_key_citations": 6,
"score": 1,
"title": "Pulsed laser ablation in liquid for micro /nanostructure generation",
"venue": "",
"year": 2012
},
{
"abstract": "Abstract A continuous wave 250 W CO2 laser operating at 10.6 mm has been employed to evaporate graphite/bi metal targets in a vertical evaporation chamber. Without the help of an additional furnace, web like soot material has been easily produced. This contains high densities of bundles of single walled nanotubes (SWNTs) Electron microscopy, Raman spectroscopy and neutron diffraction show the high quality of the SWNT material. The use of this simple laser ablation system offers additional possibilities to study experimental parameters important for the formation of SWNTs leading to a better understanding of its growth mechanism.",
"author_names": [
"Wolfgang K Maser",
"Edgar Munoz",
"Ana M Benito",
"M Teresa Martinez",
"G de la Fuente",
"Yves Maniette",
"Eric Anglaret",
"J L Sauvajol"
],
"corpus_id": 95546445,
"doc_id": "95546445",
"n_citations": 196,
"n_key_citations": 0,
"score": 0,
"title": "Production of high density single walled nanotube material by a simple laser ablation method",
"venue": "",
"year": 1998
},
{
"abstract": "Abstract The laser ablation method was employed to synthesize Ag nanoparticles. With the aid of the surfactants, SDS and CTAB, highly dispersed Ag particles were attained. Using a laser intensity of 120 mJ/pulse particle diameters of 4.2+ 1.9 nm were produced in SDS and 7.8+ 4.5 nm in CTAB. The anionic SDS and cationic CTAB exhibited differential ability in protecting Ag colloids: the particles containing SDS remained stable at least one month, while the CTAB protected Ag precipitated completely within one week. Plausible explanations were given to such stability observations. Moreover, the changes in the ablation laser powers were found to achieve particle size control. Lesser laser intensity of 60 mJ/pulse produced larger particle sizes of 6.8+ 2.7 nm and 9.4+ 5.9 nm in SDS and CTAB, respectively.",
"author_names": [
"Yu-Hung Chen",
"Chen-Sheng Yeh"
],
"corpus_id": 96625346,
"doc_id": "96625346",
"n_citations": 195,
"n_key_citations": 4,
"score": 0,
"title": "Laser ablation method: use of surfactants to form the dispersed Ag nanoparticles",
"venue": "",
"year": 2002
},
{
"abstract": "By searching the title, publisher, or authors of guide you in point of fact want, you can discover them rapidly. In the house, workplace, or perhaps in your method can be every best place within net connections. If you seek to download and install the Laser Ablation In Liquids Principles And Applications In The Preparation Of Nanomaterials, it is categorically simple then, in the past currently we extend the connect to purchase and make bargains to download and install Laser Ablation In Liquids Principles And Applications In The Preparation Of Nanomaterials so simple!",
"author_names": [
"Guowei Yang"
],
"corpus_id": 99835256,
"doc_id": "99835256",
"n_citations": 170,
"n_key_citations": 5,
"score": 0,
"title": "Laser Ablation in Liquids: Principles and Applications in the Preparation of Nanomaterials",
"venue": "",
"year": 2012
},
{
"abstract": "Abstract Laser ablation inductively coupled plasma mass spectrometry (LA ICP MS) has become a most powerful technique for the elemental analysis of individual, polyphase inclusions completely enclosed in minerals, be they solid or a solid liquid gas mixture at the time of measurement. Simultaneous, accurate quantification of major to ultra trace element concentrations from Li to U by well controlled ablation of the entire fluid or melt inclusion content and successful use of largely matrix independent external calibration protocols are unique features of this method. This contribution reviews fluid inclusion fundamentals relevant for their bulk analysis by LA ICP MS and discusses key aspects of the analytical protocol. Emphasis is on figures of merit (precision, accuracy) obtained from the analysis of individual inclusions and fluid inclusion assemblages, and procedures and technical developments to improving data quality are elaborated. A new equation for the calculation of detection limits for LA ICP MS analysis is presented, which closely follows IUPAC conventions. Applications are reviewed with emphasis on the use of synthetic fluid inclusions in constraining metal solubility and distribution between co existing phases. New data for natural bismuth \"fluid\" inclusions document the seamless transition to melt inclusion analysis by LA ICP MS, thus highlighting the fact that the procedures presented here are generally applicable to the analysis of inclusions in complex host minerals. Isotope ratio analysis of individual fluid inclusions by multicollector ICP MS (MC ICP MS) is a recent development that requires fast transient signals to be accurately recorded by instrumentation designed for high precision static measurements of long lasting stable ion beams. We address the general principles based on Pb isotopes and review a first application to the Bingham Canyon porphyry Cu Au Mo deposit. A pilot study using about 50 synthetic fluid inclusions containing SRM 987 Sr and variable NaCl, Ca, and Rb concentrations demonstrates that accurate 87 Sr/ 86 Sr isotope ratios can be obtained on an individual Rb poor fluid inclusion, at absolute 2 s precisions of 0.0003 to 0.002. A residual trend in 87 Sr/ 86 Sr as a function of the Rb/Sr abundance ratio in the fluid inclusions suggests that interference correction of 87 Rb on mass 87 assuming identical mass bias coefficients for the two elements may be inaccurate; however, the offset can be accurately corrected for by regressing the data to zero 87 Rb. The versatility and detection power of LA ICP MS makes this technique the method of choice for solute abundance and isotope ratio analysis of individual fluid inclusions. Significant future progress can be achieved by improvements in ion production, transmission and data recording efficiency and by further improving control on inclusion ablation by pulsed laser beams. Data quantification strategies may also have to be further refined to keep pace with instrumental progress and innovation.",
"author_names": [
"Thomas Pettke",
"Felix Oberli",
"Andreas Audetat",
"Marcel Guillong",
"Adam C Simon",
"Jacob J Hanley",
"Leonhard M Klemm"
],
"corpus_id": 93111813,
"doc_id": "93111813",
"n_citations": 174,
"n_key_citations": 8,
"score": 0,
"title": "Recent developments in element concentration and isotope ratio analysis of individual fluid inclusions by laser ablation single and multiple collector ICP MS",
"venue": "",
"year": 2012
},
{
"abstract": "ABSTRACT New analytical techniques for multiparametric characterisation of individual cells are likely to reveal important information about the heterogeneity of immunological responses at the single cell level. In this proof of principle study, laser ablation inductively coupled plasma mass spectrometry (LA ICP MS) was applied to the problem of concurrently detecting 24 lineage and activation markers expressed by human leucocytes. This approach was sufficiently sensitive and specific to identify subpopulations of isolated T, B, and natural killer cells. Leucocyte subsets were also accurately detected within unfractionated peripheral blood mononuclear cells preparations. Accordingly, we judge LA ICP MS to be a suitable method for assessing expression of multiple tissue antigens in solid phase biological specimens, such as tissue sections, cytospins, or cells grown on slides. These results augur well for future development of LA ICP MS based bioimaging instruments for general users.",
"author_names": [
"Robert W Hutchinson",
"Katherine M McLachlin",
"Paloma Riquelme",
"Jan Haarer",
"Christiane Broichhausen",
"Uwe Ritter",
"Edward Kenneth Geissler",
"James A Hutchinson"
],
"corpus_id": 8905840,
"doc_id": "8905840",
"n_citations": 140,
"n_key_citations": 15,
"score": 0,
"title": "Laser Ablation Inductively Coupled Plasma Mass Spectrometry",
"venue": "Transplantation direct",
"year": 2015
},
{
"abstract": "Laser ablation inductively coupled plasma mass spectrometry (LA ICP MS) was utilized for spatially resolved bioimaging of the distribution of silver and gold nanoparticles in individual fibroblast cells upon different incubation experiments. High spatial resolution was achieved by optimization of scan speed, ablation frequency, and laser energy. Nanoparticles are visualized with respect to cellular substructures and are found to accumulate in the perinuclear region with increasing incubation time. On the basis of matrix matched calibration, we developed a method for quantification of the number of metal nanoparticles at the single cell level. The results provide insight into nanoparticle/cell interactions and have implications for the development of analytical methods in tissue diagnostics and therapeutics.",
"author_names": [
"Daniel Drescher",
"Charlotte Giesen",
"Heike Traub",
"Ulrich Panne",
"Janina Kneipp",
"Norbert Jakubowski"
],
"corpus_id": 35189199,
"doc_id": "35189199",
"n_citations": 156,
"n_key_citations": 6,
"score": 0,
"title": "Quantitative imaging of gold and silver nanoparticles in single eukaryotic cells by laser ablation ICP MS.",
"venue": "Analytical chemistry",
"year": 2012
},
{
"abstract": "BACKGROUND: Stereotactic laser ablation offers an advantage over open surgical procedures for treatment of epileptic foci, tumors, and other brain pathology. Robot assisted stereotactic laser ablation could offer an accurate, efficient, minimally invasive, and safe method for placement of an ablation catheter into the target. OBJECTIVE: To determine the feasibility of placement of a stereotactic laser ablation catheter into a brain lesion with the use of robotic assistance, via a safe, accurate, efficient, and minimally invasive manner. METHODS: A laser ablation catheter (Visualase, Inc) was placed by using robotic guidance (ROSA, Medtech Surgical, Inc) under general anesthesia into a localized epileptogenic periventricular heterotopic lesion in a 19 year old woman with 10 year refractory focal seizure history. The laser applicator (1.65 mm diameter) position was confirmed by using magnetic resonance imaging (MRI) Ablation using the Visualase system was performed under multiplanar imaging with real time thermal imaging and treatment estimates in each plane. A postablation MRI sequence (T1 postgadolinium contrast injection) was used to immediately confirm the ablation. RESULTS: MRI showed accurate skin entry point and trajectory, with the applicator advanced to the lesion's distal boundary. Ablation was accomplished in less than 3 minutes of heating. The overall procedure, from time of skin incision to end of last ablation, was approximately 90 minutes. After confirmation of proper lesioning by using a T1 contrast enhanced MRI, the applicator was removed, and the incision was closed using a single stitch. No hemorrhage or other untoward complication was visualized. The patient awoke without any complication, was observed overnight after admitting to a regular floor bed, and was discharged to home the following day. CONCLUSION: This technique, using a combination of Visualase laser ablation, ROSA robot, and intraoperative MRI, facilitated a safe, efficacious, efficient, and minimally invasive approach that could be used for placement of 1 or multiple electrodes in the future. ABBREVIATIONS: EEG, electroencephalography SEEG, stereoelectroencephalography",
"author_names": [
"Jorge A Gonzalez-Martinez",
"Sumeet Vadera",
"Jeffrey P Mullin",
"Rei Enatsu",
"Andreas V Alexopoulos",
"Ravish V Patwardhan",
"William Bingaman",
"Imad M Najm"
],
"corpus_id": 1450750,
"doc_id": "1450750",
"n_citations": 134,
"n_key_citations": 1,
"score": 0,
"title": "Robot Assisted Stereotactic Laser Ablation in Medically Intractable Epilepsy: Operative Technique",
"venue": "Neurosurgery",
"year": 2014
},
{
"abstract": "In this paper, we demonstrated the fabrication of high active and high sensitive Au nanoparticles by laser ablation in liquid (LAL) method, and their application in electrochemical detection of heavy metal ions. First, LAL method are used to fabricate Au nanoparticles in water in a clean way. Second, the Au nanoparticles were assembled onto the surface of the glassy carbon (GC) electrode by an electrophoretic deposition method to form an AuNPs/GC electrode for electrochemical characterization and detection. Through differential pulse anodic stripping voltammetry method, it shows that the AuNPs/GC electrode could be used for the simultaneous and selective electrochemical detection of Cd(2+ Pb(2+ Cu(2+ and Hg(2+ By studying the influence of test conditions to optimize the electrochemical detection, we can detect Cd(2+ Pb(2+ Cu(2+ and Hg(2+ simultaneously with a low concentration of 3 x 10( 7) M in the experiments.",
"author_names": [
"Xiaoxiao Xu",
"Guotao Duan",
"Yue Li",
"Guangqiang Liu",
"Jingjing Wang",
"Hongwen Zhang",
"Zhengfei Dai",
"Weiping Cai"
],
"corpus_id": 32831727,
"doc_id": "32831727",
"n_citations": 114,
"n_key_citations": 0,
"score": 0,
"title": "Fabrication of gold nanoparticles by laser ablation in liquid and their application for simultaneous electrochemical detection of Cd2+ Pb2+ Cu2+ Hg2+",
"venue": "ACS applied materials interfaces",
"year": 2014
}
] |
Chiral Majorana fermion modes in a quantum anomalous Hall insulator–superconductor structure | [
{
"abstract": "A propagating Majorana mode Although Majorana fermions remain elusive as elementary particles, their solid state analogs have been observed in hybrid semiconductor superconductor nanowires. In a nanowire setting, the Majorana states are localized at the ends of the wire. He et al. built a two dimensional heterostructure in which a one dimensional Majorana mode is predicted to run along the sample edge (see the Perspective by Pribiag) The heterostructure consisted of a quantum anomalous Hall insulator (QAHI) bar contacted by a superconductor. The authors used an external magnetic field as a \"knob\" to tune into a regime where a Majorana mode was propagating along the edge of the QAHI bar covered by the superconductor. A signature of this propagation half quantized conductance was then observed in transport experiments. Science, this issue p. 294; see also p. 252 Transport experiments showing half integer quantized conductance indicate a propagating Majorana edge mode. Majorana fermion is a hypothetical particle that is its own antiparticle. We report transport measurements that suggest the existence of one dimensional chiral Majorana fermion modes in the hybrid system of a quantum anomalous Hall insulator thin film coupled with a superconductor. As the external magnetic field is swept, half integer quantized conductance plateaus are observed at the locations of magnetization reversals, giving a distinct signature of the Majorana fermion modes. This transport signature is reproducible over many magnetic field sweeps and appears at different temperatures. This finding may open up an avenue to control Majorana fermions for implementing robust topological quantum computing.",
"author_names": [
"Qing Lin He",
"Lei Pan",
"Alex Stern",
"Edward C Burks",
"Xiaoyu Che",
"Gen Yin",
"Jing Wang",
"Biao Lian",
"Quan Zhou",
"Eun Sang Choi",
"Koichi Murata",
"Xufeng Kou",
"Zhijie Chen",
"Tianxiao Nie",
"Qiming Shao",
"Yabin Fan",
"Shou-Cheng Zhang",
"Kai Liu",
"Jing Xia",
"Kang L Wang"
],
"corpus_id": 3904085,
"doc_id": "3904085",
"n_citations": 380,
"n_key_citations": 2,
"score": 1,
"title": "Chiral Majorana fermion modes in a quantum anomalous Hall insulator superconductor structure",
"venue": "Science",
"year": 2017
},
{
"abstract": "The conductance measurement of a half quantized plateau in a quantum anomalous Hall insulator superconductor structure is reported by a recent experiment [Q. L. He \\textit{et al. Science 357, 294 299 (2017) which suggests the existence of the chiral Majorana fermion modes. However, such half quantized conductance plateau may also originates from a disorder induced metallic phase. To identify the exact mechanism, we study the transport properties of such a system in the presence of strong disorders. Our results show that the local current density distributions of these two mechanisms are different. In particular, the current noises measurement can be used to distinguish them without any further fabrication of current experimental setup.",
"author_names": [
"Yu-Hang Li",
"Jie Liu",
"Haiwen Liu",
"Hua Jiang",
"Qing-feng Sun",
"X C Xie"
],
"corpus_id": 119343781,
"doc_id": "119343781",
"n_citations": 12,
"n_key_citations": 0,
"score": 0,
"title": "Noise signatures for determining chiral Majorana fermion modes",
"venue": "",
"year": 2018
},
{
"abstract": "The discovery of Chiral Majorana fermion modes in a quantum anomalous Hall insulator superconductor structure (arXiv:1606.05712) has been widely discussed since its publication in Science, including a commentary by Jason Alicea in the July issue of the Journal Club. As it should be, a breakthrough announcement such as this is being scrutinized for alternative interpretations. In the case of the 2012 report of a Majorana zero mode such critical examinations have helped a lot in strengthening the experimental claim, and I presume the same will happen here. It is in that constructive spirit that I wish to discuss the two preprints by Ji Wen and by Huang, Setiawan Sau, which address the question: How unique a signature of Majorana fermions is a conductance plateau at half the conductance quantum? To appreciate the issue, we recall that in this context a quasiparticle is called a Majorana fermion if it is a coherent equal weight superposition of a Dirac fermion and its antiparticle (electron e and hole h) The Majorana fermion is charge neutral, but so is an incoherent equal weight mixture of electrons and holes. Since the former has been dubbed the \"angel particle\" one might stay true to this theme and call the latter a \"demon\" As explained in Figure 1, a conductance measurement cannot distinguish between the current carried by the coherent superposition psangel 2 1/2(|e> |h> and the incoherent mixture rdemon 1 2 |e> <e| |h> <h| both give rise to a conductance of 1 2 e/h. For a Majorana fermion the equal weight property is fundamental: it is required by electron hole symmetry at the Fermi level. The incoherent electron hole mixture is not so constrained, and one might wonder how reasonable it is to assume a charge neutral mixture.",
"author_names": [
"Xiao-Gang Wen",
"Jay Deep Sau"
],
"corpus_id": 102343637,
"doc_id": "102343637",
"n_citations": 8,
"n_key_citations": 0,
"score": 0,
"title": "2 h Th Conductance Plateau without 1 D Chiral Majorana Fermions",
"venue": "",
"year": 2017
},
{
"abstract": "Significance With the recent involvement of large companies in the development of quantum computation, we are at a stage where this technology appears to be being realized. However, we also urgently need new materials to engineer qubits that are more immune to quantum decoherence processes and can easily be entangled. Majorana fermion in the form of condensed matter quasiparticles is considered the key to a topological qubit that would be much more robust against decoherence. One way to develop such a qubit is to introduce superconductivity into a quantum anomalous Hall insulator. We provide spectroscopic evidence of chiral Majorana modes in this material in qualitatively good agreement with the theoretical predictions. With the recent discovery of the quantum anomalous Hall insulator (QAHI) which exhibits the conductive quantum Hall edge states without external magnetic field, it becomes possible to create a topological superconductor (SC) by introducing superconductivity into these edge states. In this case, 2 distinct topological superconducting phases with 1 or 2 chiral Majorana edge modes were theoretically predicted, characterized by Chern numbers (N) of 1 and 2, respectively. We present spectroscopic evidence from Andreev reflection experiments for the presence of chiral Majorana modes in an Nb/(Cr0.12Bi0.26Sb0.62)2Te3 heterostructure with distinct signatures attributed to 2 different topological superconducting phases. The results are in qualitatively good agreement with the theoretical predictions.",
"author_names": [
"Junying Shen",
"Jian Lyu",
"Jason Z Gao",
"Yingming Xie",
"Chui-zhen Chen",
"Chang-Woo Cho",
"Omargeldi Atanov",
"Zhijie Chen",
"Kai Liu",
"Y J Hu",
"King Yau Yip",
"Swee K Goh",
"Qing Lin He",
"Lei Pan",
"Kang L Wang",
"Kam Tuen Law",
"Rolf Lortz"
],
"corpus_id": 209416929,
"doc_id": "209416929",
"n_citations": 10,
"n_key_citations": 0,
"score": 0,
"title": "Spectroscopic fingerprint of chiral Majorana modes at the edge of a quantum anomalous Hall insulator/superconductor heterostructure",
"venue": "Proceedings of the National Academy of Sciences",
"year": 2019
},
{
"abstract": "Topological superconductors are in the focus of research because of their high potential for future applications of quantum computation. With the recent discovery of the quantum anomalous Hall insulator (QAHI) which exhibits the conductive quantum Hall edge states without external magnetic field, it becomes possible to create a novel topological superconductor by introducing superconductivity into these edge states. In this case, two distinct topological superconducting phases with one or two chiral Majorana edge modes formed, characterized by Chern numbers (N of 1 and 2, respectively. Recent experiments on a QAHI superconductor (SC) heterostructure revealed the presence of integer and half integer quantized plateaus in the conductance over a deposited SC strip and presented the quantization evidence of these states. However, these results also provoked a few controversies and thus additional direct evidence of a superconducting origin is urgently needed. We provided spectroscopic evidence for a superconducting QAHI state using nano point contacts at the edge of a QAHI SC heterostructure and obtained unique signatures of these two different topological superconducting phases. The phase with N 1 with a 2e^2/h conduction signature occurs in a narrow field regime during the QAHI magnetization reversal just before the QAHI enters the trivial insulating state. These results are consistent with theoretical analysis and further reaffirm the previous result of 1/2 quantization due to Majorana fermion.",
"author_names": [
"J Shen",
"Jian Lyu",
"J Z Gao",
"Y M Xie",
"C -Z Chen",
"Chang-Woo Cho",
"Omargeldi Atanov",
"Zeshun Chen",
"K Liu",
"Y J Hu",
"King Yau Yip",
"Swee K Goh",
"Qing Lin He",
"Lei Pan",
"K L Wang",
"Kam Tuen Law",
"Rolf Lortz"
],
"corpus_id": 119367573,
"doc_id": "119367573",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Spectroscopic evidence of chiral Majorana modes in a quantum anomalous Hall insulator superconductor heterostructure",
"venue": "",
"year": 2018
},
{
"abstract": "Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong. Department of Physics, Southern University of Science and Technology, 1088 Xueyuan Road, Nanshan District, Shenzhen, Guangdong Province, China Physics Department, University of California, Davis, CA 95616, USA. Physics Department, Georgetown University, Washington, DC 20057, USA. Department of Physics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong. Department of Electrical and Computer Engineering, Department of Physics, and Department of Materials Science and Engineering, University of California, Los Angeles, CA 90095, USA. International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China.",
"author_names": [
"J Shen",
"Jian Lyu",
"J Z Gao",
"C -Z Chen",
"Chang-Woo Cho",
"Omargeldi Atanov",
"Z Chen",
"K Liu",
"Y J Hu",
"Y K",
"",
"Swee K Goh",
"Qing Lin He",
"Lei Pan",
"K L Wang",
"Kam Tuen Law",
"Rolf Lortz"
],
"corpus_id": 146120499,
"doc_id": "146120499",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Fingerprint of chiral Majorana modes in resonant Andreev reflection at the edge of a quantum anomalous Hall insulator superconductor heterostructure",
"venue": "",
"year": 2019
},
{
"abstract": "Chiral Majorana edge modes are theoretically proposed to perform braiding operations for the potential quantum computation. Here, we suggest a scheme to regulate trajectories of the chiral Majorana fermion based on a quantum anomalous Hall insulator (QAHI) topological superconductor heterostructure. An applied external gate voltage to the QAHI region introduces a dynamical phase so that the outgoing Majorana fermions can be prominently tuned to different leads. The trajectory is mechanically analyzed and the electrical manipulation is represented by the oscillating transmission coefficients versus the gate voltage. Through the optimization of devices, the conductance is likewise detectable to be periodically oscillating, which means an experimental control of chiral Majorana edge modes. Besides, this oscillating period which is robust against disorder also provides an attainable method of observing the energy dispersion relation of the edge mode of the QAHI. Furthermore, the oscillating behavior of conductance serves as smoking gun evidence of the existence of the chiral Majorana fermion, which could be experimentally confirmed.",
"author_names": [
"Qing Yan",
"Yan-Feng Zhou",
"Qing-feng Sun"
],
"corpus_id": 208910310,
"doc_id": "208910310",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Electrically tunable chiral Majorana edge modes in quantum anomalous Hall insulator topological superconductor systems",
"venue": "",
"year": 2019
},
{
"abstract": "With the recent discovery of the quantum anomalous Hall insulator (QAHI) which exhibits the conductive quantum Hall edge states without external magnetic field, it becomes possible to create a novel topological superconductor by introducing superconductivity into these edge states. In this case, two distinct topological superconducting phases with one or two chiral Majorana edge modes were theoretically predicted, characterized by Chern numbers (N of 1 and 2, respectively. We present spectroscopic evidence from Andreev reflection experiments for the presence of chiral Majorana modes in a Nb (Cr0.12Bi0.26Sb0.62)2Te3 heterostructure with unique signatures attributed to two different topological superconducting phases. The results are consistent with the theoretical predictions.",
"author_names": [
"J Shen",
"Jian Lyu",
"J Z Gao",
"C -Z Chen",
"Chang-Woo Cho",
"Omargeldi Atanov",
"Zigao Chen",
"K Liu",
"Y J Hu",
"King Yau Yip",
"Swee K Goh",
"Qing Lin He",
"Lei Pan",
"K L Wang",
"Kam Tuen Law",
"Rolf Lortz"
],
"corpus_id": 158047074,
"doc_id": "158047074",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Fingerprint of Chiral Majorana Modes in Andreev Reflection at the Edge of a Quantum Anomalous Hall Insulator Superconductor Heterostructure",
"venue": "",
"year": 2018
},
{
"abstract": "",
"author_names": [
"Qing Lin He",
"Lei Pan",
"Gen Yin",
"Xufeng Kou",
"Kang L Wang"
],
"corpus_id": 199602049,
"doc_id": "199602049",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Chiral Majorana edge state in a quantum anomalous Hall insulator superconductor structure",
"venue": "",
"year": 2017
},
{
"abstract": "This is a short note presenting a repeated experiment of the half quantized transport signature given by Majorana chiral modes living in a heterostructure formed by an s wave superconductor and a quantum anomalous Hall insulator.",
"author_names": [
"Peng Zhang",
"Lei Pan",
"Gen Yin",
"Qing-Lin He",
"Kang L Wang"
],
"corpus_id": 139106025,
"doc_id": "139106025",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "A Note on Half quantized Conductance Plateau of Chiral Majorana in Quantum Anomalous Hall Insulator and Superconductor Structures",
"venue": "",
"year": 2019
}
] |
Integrated On-Chip Inductors using magnetic material | [
{
"abstract": "On chip inductors with magnetic material are integrated into both advanced 130 and 90 nm complementary metal oxide semiconductor processes. The inductors use aluminum or copper metallization and amorphous CoZrTa magnetic material. Increases in inductance of up to 28 times corresponding to inductance densities of up to 1.3 m H mm 2 were obtained, significantly greater than prior values for on chip inductors. With such improvements, the effects of eddy currents, skin effect, and proximity effect become clearly visible at higher frequencies. The CoZrTa was chosen for its good combination of high permeability, good high temperature stability 250 deg C high saturation magnetization, low magnetostriction, high resistivity, minimal hysteretic loss, and compatibility with silicon technology. The CoZrTa alloy can operate at frequencies up to 9.8 GHz but trade offs exist between frequency, inductance, and quality factor. The effects of increasing the magnetic thickness on the permeability spectra were measured and modeled. The inductors use magnetic vias and elongated structures to take advantage of the uniaxial magnetic anisotropy. Techniques are presented to extract a sheet inductance and examine the effects of magnetic vias on the inductors. The inductors with thick copper and thicker magnetic films have resistances as low as 0.04 O and quality factors up to 8 at frequencies as low as 40 MHz.",
"author_names": [
"Donald S Gardner",
"Gerhard Schrom",
"Peter Hazucha",
"Fabrice Paillet",
"Tanay Karnik",
"Shekhar Beaverton Borkar",
"Roy Hallstein",
"T Dambrauskas",
"Charles Hill",
"C D Linde",
"Wojciech Worwag",
"Robert Baresel",
"Sriram Muthukumar"
],
"corpus_id": 122323557,
"doc_id": "122323557",
"n_citations": 101,
"n_key_citations": 4,
"score": 1,
"title": "Integrated on chip inductors using magnetic material (invited)",
"venue": "",
"year": 2008
},
{
"abstract": "In this paper we present ultra low loss magnetic inductors integrate able in the far BEOL across technology nodes for power management applications such as DC DC convertors. Our inductors have inductance densities as high as 158 nH/mm2 up to 100 MHz, Q factors >20 and a high saturation current of 1.77 A in 1mm2 area with 50 um thickness. The inductors also maintain a Q factor >10 after considering the large signal losses, which makes them suitable for handling high DC load currents and large AC ripples at high frequencies, such as in integrated voltage regulators. This is possible by using a highly optimized laminated magnetic material as core that enables very high saturation current and ultra low losses. Hence, our inductors can replace the existing on board, bulky and lossy inductors in power convertors including voltage regulators for CPUs/GPUs.",
"author_names": [
"Zishan Ali",
"Lulu Peng",
"Patrick Rohlfs",
"Yong Chau Ng",
"Lothar Lehmann",
"Chor Shu Cheng",
"Lawrence Selvaraj",
"Marcel Wieland"
],
"corpus_id": 235455611,
"doc_id": "235455611",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Ultra low loss on chip magnetic inductors in the far BEOL for high frequency power electronics",
"venue": "2021 33rd International Symposium on Power Semiconductor Devices and ICs (ISPSD)",
"year": 2021
},
{
"abstract": "Integrated on chip inductors with high quality factors are demonstrated using a low loss artificial conductor technology. This concept is based on an artificial layered meta material comprising a bi layered Ni80Fe20/Cu superlattice. By properly tailoring the thickness ratio between the non magnetic and magnetic metallic layers, the skin effects can be effectively suppressed within a wide frequency range, and can be tuned to a minimum at the frequency of interest up to 67 GHz. The quality factor has been increased by 41% of a 2nH inductor at 14.5GHz. The bandwidth of skin effect suppression is obtained between 10 18 GHz.",
"author_names": [
"I Iramnaaz",
"T Sandoval",
"Y Zhuang",
"Hugo Schellevis",
"B Rejaei"
],
"corpus_id": 20989640,
"doc_id": "20989640",
"n_citations": 7,
"n_key_citations": 2,
"score": 0,
"title": "High quality factor RF inductors using low loss conductor featured with skin effect suppression for standard CMOS/BiCMOS",
"venue": "2011 IEEE 61st Electronic Components and Technology Conference (ECTC)",
"year": 2011
},
{
"abstract": "FO WLP with integrated solenoidal magnetic core inductor in the RDL layer was proposed and developed in this work. This provide a packaging solution to integrate high performance inductors for high efficiency power conversion to the embedded device chips without sacrificing valuable chip estate as compared to integrating the inductors on the surface of device chip. Two photo dielectric materials were evaluated and it was found that material with higher tensile strength and percent elongation was able to sustain the magnetic film deposition and patterning process without showing cracks or delamination. Different patterning methods of the magnetic film were explored. Wet etching method has residue issues on low lying features in valley and contact vias. The sidewall of the magnetic core was highly sloped for thicker magnetic film due isotropic nature of the wet process. Dry etching was inefficient to etch the thick magnetic film. A new patterning method was developed to overcome the wet etching issues to produce magnetic core with vertical sidewall with no residue issues. Electrical characterization was performed on the fabricated inductor. The inductor shows a flat inductance response up to its self resonance frequency, and a quality factor of 14 can be achieved. These indicates that the inductor has low loss and can be utilized in high efficient power conversion.",
"author_names": [
"Soh Siew Boon",
"David Ho Soon Wee",
"Raju Salahuddin",
"Ravinder Pal Singh"
],
"corpus_id": 212645669,
"doc_id": "212645669",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Magnetic Inductor Integration in FO WLP using RDL first Approach",
"venue": "2019 IEEE 21st Electronics Packaging Technology Conference (EPTC)",
"year": 2019
},
{
"abstract": "A novel on chip magnetic bead separator using micromachined magnetic tips for biocell sorting in microfluidic systems is presented. Magnetic interconnection technology is applied by using through holes filled with NiFe permalloy material, which allows the fully integrated electromagnetic inductors to be placed underneath the device chip. Only the magnetic tips on the front side of the chip are exposed to integrated microchannels, which give wide flexibility in constructing microfluidic systems with the magnetic bead separator. Magnetic beads were separated effectively from a continuous flow using the developed on chip magnetic bead separator.",
"author_names": [
"Rong Rong",
"Jin-Woo Choi",
"Chong H Ahn"
],
"corpus_id": 108513157,
"doc_id": "108513157",
"n_citations": 55,
"n_key_citations": 0,
"score": 0,
"title": "An on chip magnetic bead separator for biocell sorting",
"venue": "",
"year": 2006
},
{
"abstract": "Inductors are important components of analog circuit designs, from matching circuitry to passive filters. In this study, the application of electrophoretically deposited nano ferrite material has been investigated as a technique to increase the inductance of integrated copper planar inductors fabricated using copper plating and chemical mechanical planarization. Sintered Mn Zn ferrite particles are suspended in a medium of isopropyl alcohol with magnesium nitrate and lanthanum nitrate salts. The transportation of the particles to the substrate surface is assisted by applied electric field and particles adhere to the substrate surface by a glycerol based surfactant. Electrophorectic deposition process forms a self aligned polymeric thin film on the surface of a p type silicon substrate selectively with respect to copper. This ferrite deposition method yields high selectivity to the inductor coils and patterned silicon substrates compatible with standard silicon technology.",
"author_names": [
"Cody M Washburn",
"Daniel Brown",
"Jay Cabacungan",
"Jayanti Venkataraman",
"Santosh Kurinec"
],
"corpus_id": 139014881,
"doc_id": "139014881",
"n_citations": 5,
"n_key_citations": 1,
"score": 0,
"title": "Application of Magnetic Ferrite Electrodeposition and Copper Chemical Mechanical Planarization for On Chip Analog Circuitry",
"venue": "",
"year": 2005
},
{
"abstract": "Improved Resistivity (r) and Anisotropy field (Hk) could result in CoP performance greater than sputttered CoTaZr, with improved performance at high frequency and an increased deposition rate Acknowledgements: Intel Corporation Enterprise Ireland Tyndall National Institute References i D.S. Gardner, G. Schrom, P. Hazucha, et al. \"Integrated on chip inductors using magnetic material\" J. Appl. Phys. 103, 07E927 1 (2008) ii Satish Prabhakaran et al. IEEE Trans. On Magnetics. 39, 3190 (2003) iii D.S. Gardner, G. Schrom, P. Hazucha, et al. \"Integrated on chip inductors using magnetic material\" J. Appl. Phys. 103, 07E927 1 (2008) iv W.P. Jayasekara, J.A. Mabin, M.H. Kryder, IEEE T. Mag. 34(4) 1438 (1998) High frequency complex permeability curves for selected magnetic materials and fit to theoretical model 200 0 200 400 600 80",
"author_names": [
"Brice Jamieson",
"Paul McCloskey",
"Saibal Roy"
],
"corpus_id": 137940004,
"doc_id": "137940004",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Optimization of magnetic enhancement layers for high frequency transmission line micro inductors",
"venue": "",
"year": 2008
},
{
"abstract": "Recently, more and more applications have used planar inductors not only on silicon substrate but also on ceramic or polymer substrates (rigid or flex) Inductors integrated in today's silicon process could not fulfil the requirements for performance of modern communication equipments. Sometimes for system in package applications high quality inductors and other passive components are placed outside from chip and are realized using organic or non organic substrate. This paper presents the results of investigation on the planar inductor as electrical performance (inductance, quality factor, self resonance frequency) according with manufacturing technology and substrate (organic or non organic) shape (square or spiral) number of layers (single or double layer) The influence of a magnetic material and it's influence on overall parameters of the inductor will also be analyzed",
"author_names": [
"Paul Svasta",
"Ciprian Ionescu",
"Virgil Golumbeanu",
"Norocel Codreanu",
"A Romanescu",
"Alena Pietrikova",
"Jenica Neamtu"
],
"corpus_id": 2305577,
"doc_id": "2305577",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Electromagnetic Behavior of Inductive Planar Structures with Non Homogenous Magnetic Environment",
"venue": "2006 1st Electronic Systemintegration Technology Conference",
"year": 2006
},
{
"abstract": "",
"author_names": [
"Donald S Gardner",
"Gerhard Schrom",
"Fabrice Paillet",
"Tanay Karnik",
"Shekhar Beaverton Borkar"
],
"corpus_id": 113863221,
"doc_id": "113863221",
"n_citations": 16,
"n_key_citations": 2,
"score": 0,
"title": "Integrated On Chip Inductors Using Magnetic Materials",
"venue": "",
"year": 2011
},
{
"abstract": "On chip strip line coupled inductors integrated with magnetic material are a promising technology option to enable on chip voltage regulators for improving power management in microelectronics. We report on design methodologies where several examples of parameter tradeoffs are presented. When considered with practical integration constraints, these result in an optimized structure. Strip line inductors integrated with Ni80Fe20 were then fabricated, electrically characterized, and compared to models. Electrical characterization included frequency dependent measurements of effective self and mutual inductance, effective resistance, coupling coefficient, and saturation effects.",
"author_names": [
"P Morrow",
"Chang-min Park",
"H W Koertzen",
"J T DiBene"
],
"corpus_id": 6921644,
"doc_id": "6921644",
"n_citations": 73,
"n_key_citations": 3,
"score": 0,
"title": "Design and Fabrication of On Chip Coupled Inductors Integrated With Magnetic Material for Voltage Regulators",
"venue": "IEEE Transactions on Magnetics",
"year": 2011
}
] |
VLSI Chip Design Market trends | [
{
"abstract": "As the move to very deep submicron VLSI devices pushes the threshold of semiconductor technology, conventional test and diagnosis methods become inadequate and costly. The new level of complexity driven by core based system chips demands that designers alter the way they approach chip development in order to keep up with diminishing time to market requirements and stay within budgets. Embedded test enables the production of higher quality devices in less time. The use of embedded test raises margins and significantly reduces the time required for system verification, test and debug. This paper addresses discusses embedded test technology and analyzes its impact on time to market, product quality and cost.",
"author_names": [
"Yervant Zorian"
],
"corpus_id": 62089891,
"doc_id": "62089891",
"n_citations": 10,
"n_key_citations": 0,
"score": 1,
"title": "Emerging trends in VLSI test and diagnosis",
"venue": "Proceedings IEEE Computer Society Workshop on VLSI 2000. System Design for a System on Chip Era",
"year": 2000
},
{
"abstract": "We entered the very large scale inteuration (VLSI) era in 1975. Since that time VLSI technoiugy has been, and continues to be, refined and improved. We have moved from diffusion to ion implantation, from wet etching to dry etching, and from contact printing to scanning projection or step and repeat lithography. By 1990 we will employ larger silicon wafers ~150 mm in diameter) smaller feature lengths ~0.5 um) and lower processing temperatures <900degC) Process simulation and advanced diagnostic techniques will be extensively used for on line process design and for reliability analysis, respectively. Ultra sophisticated chips with millions of components and on chip system organizations will be built in response to the enormous market demand of the Information Age. This paper discusses those advances and future trends in VLSI technology.",
"author_names": [
"S M Sze"
],
"corpus_id": 122164246,
"doc_id": "122164246",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Invited) VLSI Technology Overviews and Trends",
"venue": "",
"year": 1983
},
{
"abstract": "The increasing market trends of extremely low power operated handy applications like laptop, electronics gadgets etc requires microelectronic devices with low power consumption. It is obvious that the transistor dimensions continues to shrink and as require for more complex chips increases, power management of such deep sub micron based chip is one of the major challenges in VLSI industry. The manufacturers are always targeting for low power designs for the reason that to provide adequate physical resources to withstand against design hurdles and this lead to increases the cost and restrict the functionality of the device. This power reduction ratio is the highest among FFs that have been reported so far. The reduction is achieved by applying topological compression technique, merger of logically equivalent transistors to an eccentric latch structure. Fewer transistors, only three, connected to clock signal which reduces the power drastically, and the smaller total transistor count assures to retain the chip area as conventional FFs. In addition, fully static full swing operation makes the cell lenient of supply voltage and input slew variation. An experimental chip design with 32 nm CMOS technology shows that almost all conventional FFs are expendable with proposed FF while preserving the same system performance and layout area. The performance of this paper is evaluated on the design simulation using Microwind 3.1 simulator",
"author_names": [
"U Somalatha",
"S Chandana"
],
"corpus_id": 65179045,
"doc_id": "65179045",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Design of Low Power Topologically Compressed Static Flip Flop",
"venue": "",
"year": 2018
},
{
"abstract": "Since their introduction in the 1970s, Programmable Logic Devices (PLDs) evolved from implementing small glue logic designs to large, configurable multi processor Systems on Chip (SoC) Today's most prominent PLD technology, known as FPGA (Field Programmable Gate Array) is used in an increasing number of application domains, such as the telecom industry, the automotive electronics sector or automation technology, and recent market studies expect a continuous demand for these sophisticated microelectronic devices in the future. For small and medium enterprises and/or SME dominated countries like Austria, FPGAs can provide access to VLSI (Very Large Scale Integration) technology by avoiding the immense NRE (Non Recurring Engineering) costs of ASICs (Application Specific Integrated Circuits) This work outlines how today's and future electronic based systems can benefit from FPGA technology. Trends, tools and design flows will be explained as well as research challenges that are currently investigated within two public funded R&D projects at the University of Applied Sciences Technikum Wien. Programmierbare Logikbausteine (PLDs) haben sich seit ihrer Markteinfuhrung in den 1970er Jahren von kompakten Implementierungsmoglichkeiten fur simple Glue Logic zu komplexen programmierbaren Multiprozessor Systems on Chip (SoC) entwickelt. Die heutzutage gebrauchlichste PLD Technologie, sogenannte FPGAs (Field Programmable Gate Arrays) werden in einer Vielzahl von Applikationsdomanen, etwa in der Telekommunikation, aber auch in Bereichen wie Fahrzeugelektronik oder der Automatisierungstechnik, verwendet, wobei Marktstudien einen weiterhin steigenden Bedarf dieser hochentwickelten mikroelektronischen Bauelemente in den nachsten Jahren erwarten. Gerade fur KMU dominierte Lander wie Osterreich eroffnet die FPGA Technologie die Moglichkeit zur Realisierung von VLSI (Very Large Scale Integration) Designs unter Vermeidung der in diesem Bereich mittlerweile exorbitanten Einmalkosten bei der Herstellung von ASICs (Application Specific Integrated Circuits) Dieser Artikel beschreibt, wie moderne elektronische Systeme von den Vorteilen der FPGA Technologie profitieren konnen. Trends, Tools und Design Flows werden beschrieben sowie aktuelle Forschungsfragen, die derzeit im Rahmen zweier offentlich geforderter F&E Projekte an der FH Technikum Wien bearbeitet werden.",
"author_names": [
"Peter Rossler",
"Roland Holler"
],
"corpus_id": 211193928,
"doc_id": "211193928",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Programmable logic devices key components for today's and tomorrow's electronic based systems",
"venue": "Elektrotech. Informationstechnik",
"year": 2020
},
{
"abstract": "Since their introduction in the 1970s, Programmable Logic Devices (PLDs) evolved from implementing small glue logic designs to large, configurable multi processor Systems on Chip (SoC) Today's most prominent PLD technology, known as FPGA (Field Programmable Gate Array) is used in an increasing number of application domains, such as the telecom industry, the automotive electronics sector or automation technology, and recent market studies expect a continuous demand for these sophisticated microelectronic devices in the future. For small and medium enterprises and/or SME dominated countries like Austria, FPGAs can provide access to VLSI (Very Large Scale Integration) technology by avoiding the immense NRE (Non Recurring Engineering) costs of ASICs (Application Specific Integrated Circuits) This work outlines how today's and future electronic based systems can benefit from FPGA technology. Trends, tools and design flows will be explained as well as research challenges that are currently investigated within two public funded R&D projects at the University of Applied Sciences Technikum Wien.",
"author_names": [
"Peter Rossler",
"Roland Holler"
],
"corpus_id": 226859572,
"doc_id": "226859572",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Programmable logic devices key components for today's and tomorrow's electronic based systems",
"venue": "",
"year": 2020
},
{
"abstract": "In the past decade, CMOS technology has played a major role in the rapid ad vancement and the increased integration of VLSI systems. CMOS devices feature high input impedance, extremely low offset switches, high packing density, low switching power consumption, and most importantly, they are easily scaled. With the reduction of the device minimum feature size, in order to prevent the transistor from breakdown because of the higher electrical field across the gate oxide and to ensure its reliability, the power supply voltage is necessary to be reduced. W ith the reduction of the device minimum feature size, more and more transistors can be fabricated into a single chip. Nevertheless, the large amount of circuits inte grated in a chip result in huge power consumption. Decrease of the supply voltage can not only ensure the device reliability, but also reduce power consumption in a sig nificant amount. Furthermore, portable/mobile electronic equipments have become the trends of the present and future market demands. Low power supplies are the requirements of the portable/mobile electronic products. In this dissertation, we focus on the low voltage, low power CMOS circuit de sign. Each circuit either features a rail to rail common mode input voltage and/or consumes very low power. These circuits target applications in mobile telecommuni cations (rail to rail strong inversion circuits) and in (portable) medical applications",
"author_names": [
"Chung-Chih Hung"
],
"corpus_id": 69956062,
"doc_id": "69956062",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Low voltage, low power CMOS analog circuit design techniques for mobile, portable VLSI applications",
"venue": "",
"year": 1997
},
{
"abstract": "From the past years, research in reversible logic has done very efficiently. It includes synthesis, optimization, simulation and verification. By the reversible structure excessive garbage inputs are eliminated, which in turn the power and speed of the logic design is efficiently utilized. In this paper we are proposed an Array Multiplier which has high performance factors. From recent years the research has going on multipliers to reduce the partial product number. To eliminate this problem we introduced an array multiplier using reversible full adder and reversible half adders. Because every Very Large Scale Integrated (VLSI) circuit designers wants to their circuits should produce less delay and efficient power utilization, because to keep their designs high demands on the market. For this we proposed an array multiplier with reversible half adder and multiplexer based reversible full adder. By this design the combinational path delay and chip area are decreased. Array multiplier is an important design in VLSI because, Multiplication involves key role in Arithmetic and Logical operations. We developed all these designs using Very high speed Hardware Description Language (VHDL) and results are verified through simulation using Xilinx ISE",
"author_names": [
"K Yugandhar",
"V Ganesh Raja",
"M Tejkumar",
"Dhandapani Siva"
],
"corpus_id": 54438042,
"doc_id": "54438042",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "High Performance Array Multiplier using Reversible Logic Structure",
"venue": "2018 International Conference on Current Trends towards Converging Technologies (ICCTCT)",
"year": 2018
},
{
"abstract": "The growing need of the SoC market and recent trends in embedded systems, force designers to come up with solutions to speed up the chip design and development process. Each embedded system has to be designed in a comparatively short time with minimum bugs and these issues force the designers to adopt new techniques and technologies. In this paper a novel and speedy approach using a comparatively newer language in design, SystemVerilog is introduced. A configurable and reusable Liquid Crystal Display (LCD) Controller is designed and developed using SystemVerilog. The approach presented here is faster and more efficient compared to traditional methods of design. The LCD Controller was successfully designed, developed and validated in FPGA.",
"author_names": [
"Mithuna Chandran O",
"T T Libin",
"S Krishnakumar Rao",
"Biju C Oommen"
],
"corpus_id": 39403825,
"doc_id": "39403825",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "SystemVerilog based design and implementation of LCD Controller IP Core",
"venue": "2015 International Conference on VLSI Systems, Architecture, Technology and Applications (VLSI SATA)",
"year": 2015
},
{
"abstract": "Conventional CMOS memory i.e. Static Random Access Memory (SRAM) has been the popular choice for embedded memory application for last several decades. However, SRAM seems to be approaching a brick wall. On one hand process variability and leakage power is posing severe obstruction towards SRAM scaling to future nodes and on the other hand, emerging energy constrained and bandwidth hungry electronic gadgets demand for larger as well as energy efficient on chip cache which cannot be satisfied with SRAM. To address the changing landscape of consumer market, there is a corresponding need of changing the design paradigm. What is really needed is a memory technology that is at least 50 100X denser, 1000X energy efficient and as fast as SRAM. Several emerging memory technologies are on the horizon but there is no clear universal choice for embedded application. This tutorial will explore the latest trends in the embedded memory segment and discuss the fundamental limitations of SRAM in meeting the new needs of the electronic systems. The complex (and not very well understood) interrelationships between memory density, bandwidth, latency, power and speed will be elaborated in the context of emerging graphics applications. Next the tutorial will discuss few promising emerging memory technologies where storage element is based on charge, spin and resistance. Specifically, the tutorial will focus on the operating principles, design challenges and solutions of volatile memory such as embedded Dynamic Random Access Memory (eDRAM) and non volatile memories (NVM) such as Domain Wall Memory (DWM) and memrister. The eDRAM section of the tutorial will present the trade offs such as low power peripherals (e.g. wordline driver, sense amplifier) and its impact on random access time (tRC) and retention. The relationship between noise sources (e.g. process variations, coupling effects) and retention power will also be described. Design techniques such as pulsed sense amplifier, peripheral sleep etc. will be introduced to control and mitigate the effect of noise in high speed eDRAM arrays for future technology nodes. Next the tutorial will describe DWM which is a spin based memory technology. Various design metrics such as read/write power, speed, reliability and retention will be discussed in detail. The tutorial will address the modeling and simulation methodology for design and analysis of DWM arrays. Various design challenges such as reliable shift circuitry, positioning of read/write head, impact of process variations on sense margin, reliability of nanowire etc. will be described. Design techniques to improve robustness, operating speed and array density will also be presented. The last part of this tutorial will describe memrister where the storage element is resistive in nature. Typically memrister suffer from high access power. Design techniques to lower the power consumption such as data encoding, write pause etc. will be discussed to mitigate the power while maintaining required robustness. The audiences will be able to takeaway following key points from this tutorial (a) changing landscape of emerging electronic systems and inability of SRAM to cater to these new needs in scaled technologies, (b) emerging memory technologies for embedded applications and their relative merits in terms of density, power, speed and reliability, (c) design methodologies, challenges and potential solutions to enable these emerging memories for embedded applications.",
"author_names": [
"Swaroop Ghosh"
],
"corpus_id": 32454017,
"doc_id": "32454017",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Tutorial T6B: Embedded Memory Design for Future Technologies: Challenges and Solutions",
"venue": "VLSI Design",
"year": 2014
},
{
"abstract": "The increasing complexity of systems on chip (SoCs) has led to the critical \"design productivity gap\" problem. Several strategies are being employed to cope with this problem, including an IP based design flow, as well as platform based designs for application domains. These approaches have critically increased the amount of on chip communication. Since on chip communication architectures have a significant impact on system performance, power dissipation and time to market, system designers, as well as the research community have focused on the issue of exploring, evaluating, and designing SoC communication architectures to meet the targeted design goals. On the other hand, aggressive scaling of VLSI technology has resulted in nanoscale effects that adversely affect interconnect performance, reliability, power dissipation, and predictability; new approaches to on chip communication architectures (e.g. networks on chip) need to be devised in order to overcome these effects. The tutorial is structured into four parts, covering: i) scaling trends in nanometer interconnects and related methodology challenges; ii) architectural modeling and analysis of communication traffic and synthesis of current on chip bus based communication architectures iii) high performance bus protocols and topologies, including design examples; and iv) emerging network on chip (NoC) paradigms for next generation designs. The tutorial begins by highlighting the key emerging issues in the domain of interconnect modeling and analysis. The implications of various nanoscale effects on VLSI interconnect performance, reliability, power dissipation and parasitic extraction are also presented. Promising new technologies including 3 D ICs and carbon nanotube (CNT) interconnects are outlined which have the potential to meet these interconnect challenges in the nanometer era. The second part of the tutorial will cover modeling abstractions suitable for communication centric designs, analysis techniques for estimating bus communication traffic, and synthesis of current protocols and standards such as OCP IP, VSIA, and AMBA. The third part of the tutorial will cover the use of advanced architectural concepts in bus based communication architecture design, and will include design examples from the industry. Finally, the last part of the tutorial will introduce the basic concepts on networks on chip and the challenges involved in the deployment of this on chip communication paradigm.",
"author_names": [
"Nikil D Dutt",
"Kaustav Banerjee",
"Luca Benini",
"Kanishka Lahiri",
"Sudeep Pasricha"
],
"corpus_id": 20848293,
"doc_id": "20848293",
"n_citations": 3,
"n_key_citations": 1,
"score": 0,
"title": "Tutorial 5: SoC Communication Architectures: Technology, Current Practice, Research, and Trends",
"venue": "20th International Conference on VLSI Design held jointly with 6th International Conference on Embedded Systems (VLSID'07)",
"year": 2007
}
] |
A survey of in-spin transfer torque MRAM computing | [
{
"abstract": "In traditional von Neumann computing architectures, the essential transfer of data between the processor and memory hierarchies limits the computational efficiency of next generation system on a chip. The emerging in memory computing (IMC) approach addresses this issue and facilitates the movement of significant data and rapid computations. Among the different memory types, intrinsic energy efficiency is demonstrated by in magnetic random access memory (MRAM) computing with a low power spintronic magnetic tunnel junction device and hybrid integration at an advanced complementary metal oxide semiconductor node. This study reviews state of the art techniques for managing IMC with an emphasis on spin transfer torque MRAM computing via design schemes at the bit cell, circuit, and system levels. In addition, this study presents effective design techniques and potential challenges and demonstrates the existing limitations of in MRAM computing and potential methods for overcoming these issues. This study also considers the design technology co optimization from the IMC perspective.",
"author_names": [
"Hao Cai",
"Juntong Chen",
"Lirida A B Naviner",
"Zhen Wang"
],
"corpus_id": 235235142,
"doc_id": "235235142",
"n_citations": 1,
"n_key_citations": 0,
"score": 1,
"title": "A survey of in spin transfer torque MRAM computing",
"venue": "Sci. China Inf. Sci.",
"year": 2021
},
{
"abstract": "CMOS compatible spin transfer torque magnetic random access memory (STT MRAM) has demonstrated promising developments as the next generation embedded non volatile memory (eNVM) In this survey, we provide the state of the art multi modes reconfigurable techniques for energy efficient STT MRAM implementation. We resort to the bottom up design approach with a twofold aim: 1) summarizing related work from bit cell to circuit and system levels with conventional and emerging memories. 2) analyzing the present research status of multi modes reconfigurable techniques in MRAM, which consist of tunable bit cell configuration, in memory computing and hybrid memory system. Experimental comparisons show that both reconfiguration and in MRAM computing obtain extra design freedom. Nonvolatile data accessing cost can be well alleviated, and thereby improving energy efficiency of MRAM.",
"author_names": [
"Hao Cai",
"Juntong Chen"
],
"corpus_id": 233884536,
"doc_id": "233884536",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Toward Energy Efficient STT MRAM Design With Multi Modes Reconfiguration",
"venue": "IEEE Transactions on Circuits and Systems II: Express Briefs",
"year": 2021
},
{
"abstract": "This work is an effort to introduce advanced logic, their applications and some of their post CMOS technological implementations in \"core\" conventional logic design classroom. In this short one lecture knowledge module, we aimed at threshold logic and its most popular application, the neural computing. Majority, a special type of threshold function was also discussed and one of its post CMOS implementation was shown. A post CMOS memory called Spin Transfer Torque Magnetoresistive RAM (STT MRAM) was also introduced. The purpose of the module was to encourage research among students and to motivate them towards electives in advanced logic and post CMOS nanotechnologies. Students' feedback were collected through a pre and a post module survey. The feedback suggest that all the participants were satisfied with the module and the module was successful in fulfilling its objectives.",
"author_names": [
"Jayita Das",
"Sanjukta Bhanja"
],
"corpus_id": 27808494,
"doc_id": "27808494",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "A novel knowledge module to integrate threshold logic and post CMOS technology into undergraduate logic design classroom",
"venue": "Fourth Interdisciplinary Engineering Design Education Conference",
"year": 2014
},
{
"abstract": "In memory computing is a promising approach to addressing the processor memory data transfer bottleneck in computing systems. We propose spin transfer torque compute in memory (STT CiM) a design for in memory computing with spin transfer torque magnetic RAM (STT MRAM) The unique properties of spintronic memory allow multiple wordlines within an array to be simultaneously enabled, opening up the possibility of directly sensing functions of the values stored in multiple rows using a single access. We propose modifications to STT MRAM peripheral circuits that leverage this principle to perform logic, arithmetic, and complex vector operations. We address the challenge of reliable in memory computing under process variations by extending error correction code schemes to detect and correct errors that occur during CiM operations. We also address the question of how STT CiM should be integrated within a general purpose computing system. To this end, we propose architectural enhancements to processor instruction sets and on chip buses that enable STT CiM to be utilized as a scratchpad memory. Finally, we present data mapping techniques to increase the effectiveness of STT CiM. We evaluate STT CiM using a device to architecture modeling framework, and integrate cycle accurate models of STT CiM with a commercial processor and on chip bus (Nios II and Avalon from Intel) Our system level evaluation shows that STT CiM provides the system level performance improvements of 3.93 times on average (up to 10.4 times) and concurrently reduces memory system energy by 3.83 times on average (up to 12.4 times)",
"author_names": [
"Shubham Jain",
"Ashish Ranjan",
"Kaushik Roy",
"Anand Raghunathan"
],
"corpus_id": 875043,
"doc_id": "875043",
"n_citations": 125,
"n_key_citations": 21,
"score": 0,
"title": "Computing in Memory With Spin Transfer Torque Magnetic RAM",
"venue": "IEEE Transactions on Very Large Scale Integration (VLSI) Systems",
"year": 2018
},
{
"abstract": "Accurate modeling of magnetic tunnel junction (MTJ) is critical for design of memories such as spin transfer torque magnetoresistive random access memory (STT MRAM) and spin logic circuits such as spin flip flops. This paper reviews several static and dynamic models for the MTJ and compares them for their capabilities and limitations. Furthermore, a Verilog A model is developed to predict dynamic characteristics of the MTJ. These models are used in simulating a prototype circuit to illustrate their strengths and weaknesses.",
"author_names": [
"Aynaz Vatankhahghadim",
"Safeen Huda",
"Ali Sheikholeslami"
],
"corpus_id": 180667,
"doc_id": "180667",
"n_citations": 24,
"n_key_citations": 4,
"score": 0,
"title": "A Survey on Circuit Modeling of Spin Transfer Torque Magnetic Tunnel Junctions",
"venue": "IEEE Transactions on Circuits and Systems I: Regular Papers",
"year": 2014
},
{
"abstract": "Summary form only given. The initial predictions and subsequent definitive demonstrations of the ability of a spin polarized current that impinges onto a thin film nanomagnet to reversibly switch the orientation of its magnetic moment, and/or to excite it into microwave precession, by the torque exerted through the transfer of spin angular momentum from the incident conduction electrons, have catalyzed what is now a quite broad and very active area of spin torque research. Since those initial works, there has been remarkable progress in advancing the fundamental understanding of this new spintronics phenomenon, and in successfully moving it towards technological implementations, particularly spin torque magnetic random access memory (ST MRAM) and spin torque microwave oscillator applications, that have the potential for broad impact. In this presentation I will discuss the basics of the spin torque effect and briefly survey the various approaches that can be employed to demonstrate and study it in both all metallic, spin valve type nanostructures and, most importantly for applications, in nanoscale magnetic tunnel junctions (MTJs) I will discuss some recent work that has sought to contribute to the rapidly advancing spin torque research effort, by helping both to better understand quantitatively the details of the phenomenon and to understand and enhance the efficiency of the effect I will summarize results from studies of spin transfer switching and microwave excitation in magnetic tunnel junctions (MTJs) which include the use of the spin transfer phenomenon to quantitatively determine, through spin torque excited ferromagnetic resonance (ST FMR) both the bias dependent efficiency of the spin torque in high quality MTJs and the magnetic damping of individual free layer nanomagnets. I will also briefly describe some recent work that has been examining spin torque effects in nanoscale structures with distinctly non uniform magnetization which is giving us some new information regarding magnetic dynamics in nanoscale structures and are pointing to ways by which it may be possible to significantly reduce the spin polarized current needed for the short pulse switching of a thermally stable nanomagnet for MRAM applications. I will conclude by briefly discussing some of challenges that remain to be overcome before spin torque based technologies, particularly ST MRAM, can be successfully implemented and of the pathways that might be effectively taken to overcome those challenges.",
"author_names": [
"Robert A Buhrman"
],
"corpus_id": 25827475,
"doc_id": "25827475",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Spin Torque Writing for Next Generation MRAM Challenges and Prospects",
"venue": "2008 Device Research Conference",
"year": 2008
},
{
"abstract": "Many key electronic technologies (e.g. large scale computing, machine learning, and superconducting electronics) require new memories that are fast, reliable, energy efficient, and of low impedance at the same time, which has remained a challenge. Non volatile magnetoresistive random access memories (MRAMs) driven by spin orbit torques (SOTs) have promise to be faster and more energy efficient than conventional semiconductor and spin transfer torque magnetic memories. This work reports that the spin Hall effect of low resistivity Au0.25Pt0.75 thin films enables ultrafast antidamping torque switching of SOT MRAM devices for current pulse widths as short as 200 ps. If combined with industrial quality lithography and already demonstrated interfacial engineering, our results show that an optimized MRAM cell based on Au0.25Pt0.75 can have energy efficient, ultrafast, and reliable switching, e.g. a write energy of 50 fJ 1 fJ) for write error rate of 50% <10 5) for 1 ns pulses. The antidamping torque switching of the Au0.25Pt0.75 devices is 10 times faster than expected from a rigid macrospin model, most likely because of the fast micromagnetics due to the enhanced non uniformity within the free layer. These results demonstrate the feasibility of Au0.25Pt0.75 based SOT MRAMs as a candidate for ultrafast, reliable, energy efficient, low impedance, and unlimited endurance memory.",
"author_names": [
"Lijun Zhu",
"Lujun Zhu",
"Daniel C Ralph",
"Robert A Buhrman"
],
"corpus_id": 204976823,
"doc_id": "204976823",
"n_citations": 13,
"n_key_citations": 0,
"score": 0,
"title": "Energy Efficient Ultrafast SOT MRAMs Based on Low Resistivity Spin Hall Metal Au 0.25 Pt 0.75",
"venue": "",
"year": 2019
},
{
"abstract": "Traditional Von Neumann computing is falling apart in the era of exploding data volumes as the overhead of data transfer becomes forbidding. Instead, it is more energy efficient to fuse compute capability with memory where the data reside. Emerging spintronic technologies show remarkable versatility for the tight integration of logic and memory. In this presentation, we introduce Computational RAM (CRAM) a novel high density, reconfigurable spintronic in memory substrate, and survey several years of progress in developing the CRAM concept across the system stack from the device level all the way to applications. I. FUSING COMPUTATION AND MEMORY Classical computing platforms are not optimized for efficient data transfer, which complicates large scale data analytics in the presence of exponentially growing data volumes. Imbalanced technology scaling further exacerbates this situation by rendering data communication, and not computation, a critical bottleneck [5] Specialization in hardware cannot help in this case unless conducted in a data centric manner. Tight integration of compute capability into the memory, Processing in memory (PIM) is especially promising as the overhead of data transfer becomes forbidding at scale. The rich design space for PIM spans full fledged processors and coprocessors residing in memory [6] Until the emergence of 3Dstacking, however, the incompatibility of the state of the art logic and memory technologies prevented practical prototype designs. Still, 3D stacking can only achieve near memory processing, NMP [1] [2] [8] The main challenge remains to be fusing computation and memory without violating array regularity. Emerging spintronic technologies show remarkable versatility for the tight integration of logic and memory. This talk covers a high density, reconfigurable spintronic in memory compute substrate, Computational RAM (CRAM) [10] The basic idea is to add compute capability to the magnetic tunnel junction (MTJ) based memory cell [7] [12] without breaking the array regularity. Thereby each memory cell can participate in gate level computation as an input or as an output. Computation is not disruptive, i.e. memory cells acting as gate inputs do not loose their stored values. This idea is equally applicable to Spin Torque Transfer (STT) and SpinOrbit Torque (SOT) based technologies. CRAM can implement different types of basic Boolean gates to form a functionally complete set, therefore there is no fundamental limit to the types of computation. If implemented using SOT (STT) each column (row) in an CRAM array can have only one active gate at a time, however, computation in all columns (rows) can proceed in parallel. CRAM provides true in memory computing by reconfiguring cells within the memory array to implement logic functions. As all cells in the array are identical, inputs and outputs to logic gates do not need to be confined to a specific physical location in the array. In other words, CRAM can intiate computation at any location in the memory array on demand. II. OPERATION PRINCIPLE Without loss of generality, we will next use an STT based CRAM as a running example. In its most basic form, a CRAM array is essentially a 2D magneto resistive RAM (MRAM) When compared to the standard 1T(ransistor)1M(TJ) MRAM cell, however, each CRAM cell features an additional transistor TL (Fig.1(a) which acts as a switch between memory and logic configurations. A CRAM cell can operate as a regular MRAM memory cell or serve as an input/output to a logic gate. Each MTJ consists of two layers of ferromagnets, termed as pinned and free layers, separated by a thin insulator. The magnetic spin orientation of the pinned layer is fixed; of the free layer, controllable. Changing the orientation of the free layer entails passing a (polarized) current through the MTJ, where the current direction sets the orientation. The relative orientation of the free layer with respect to the pinned layer, i.e. anti parallel (AP) or parallel (P) gives rise to two distinct MTJ resistance levels, i.e. Rhigh and Rlow, which encode logic 1 and 0, respectively. As resistance levels represent logic states, Fig.1 depicts each MTJ by its resistance. Memory Configuration: The dashed components in Fig.1(a) capture all add ons to the standard MRAM memory cell, in order to support logic functions. When the array is configured as memory, the Logic Bit Line (LBL) is set to 0 to turn the switch TL off, and thereby to disconnect the cells from the Logic Line (LL) In this case, the array becomes equivalent to a standard MRAM array. In the following, we detail the configuration for various memory operations (where LBL is always set to 0) Data retention: The Word Line (WL) is set to 0 to isolate the cells and to prevent current flow through the MTJs. Read: WL is set to 1, to connect each MTJ to its Bit Select Line (BSL) and Memory Bit Line (MBL) A small voltage pulse applied between BSL and MBL induces a current through the MTJ, which is a function of the resistance level (i.e. logic state) and which in turn a sense amplifier attached to BSL captures. Write: WL is set to 1, to connect each MTJ to its BSL and MBL. A large enough voltage pulse (in the order of the supply voltage) is applied between BSL and MBL to induce a large enough current through the MTJ to change the spin orientation of the free layer. Logic Configuration: LL connects all cells participating in computation, on a per row basis. Such cells may act as logic gate inputs or outputs. For each CRAM cell participating in computation, WL is set to 0 to disconnect its MTJ from MBL. Instead, LBL is set to 1 to turn the switch TL on, which in turn connects the MTJ to the LL. As an example, Fig.1(b) demonstrates the formation of a two input logic gate in the array, where cells labeled by \"0\" \"1\" and \"2\" correspond to the inputs In0, In1, and the output Out, respectively. Fig.1(c) depicts the equivalent circuit: BSL of the output, BSL2, is grounded; while BSL of the two inputs,",
"author_names": [
"Masoud Zabihi",
"Zhengyang Zhao",
"Zamshed Iqbal Chowdhury",
"Salonik Resch",
"D C Mahendra",
"Thomas J Peterson",
"Ulya R Karpuzcu",
"Jianping Wang",
"Sachin S Sapatnekar"
],
"corpus_id": 155100381,
"doc_id": "155100381",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "True In memory Computing with the CRAM: From Technology to Applications",
"venue": "ACM Great Lakes Symposium on VLSI",
"year": 2019
},
{
"abstract": "Hardware implementation of artificial neural networks (ANNs) using conventional binary arithmetic units requires large area and energy, due to the massive multiplication and addition operations in the inference process, limiting their use in edge computing and emerging Internet of Things (IoT) systems. Stochastic computing (SC) where the probability of 1s and 0s in a randomly generated bit stream is used to represent a decimal number, has been devised as an alternative for compact and low energy arithmetic hardware, due to its ability to implement basic arithmetic operations using far fewer logic gates than binary operations. To realize SC in hardware, however, tunable true random number generators (TRNGs) are needed, which cannot be efficiently realized using existing complementary metal oxide semiconductor complementary metal oxide semiconductor (CMOS) technology. In this letter, we address this challenge by using magnetic tunnel junctions (MTJs) as TRNGs, the stochasticity of which can be tuned by an electric current via spin transfer torque. We demonstrate the implementation of ANNs with SC units, using stochastic bit streams experimentally generated by a series of 50 nm perpendicular MTJs. The numerical value (1 to 0 ratio) of the bit streams is tuned by the current through the MTJs via spin transfer torque with an ultralow current of <5 uA 0.25 MAcm 2) The MTJ based SC ANN achieves 95% accuracy for handwritten digit recognition on the MNIST database. MRAM based SC ANNs provide a promising solution for ultra low power machine learning in edge, mobile, and IoT devices.",
"author_names": [
"Yixin Shao",
"Sisilia Lamsari Sinaga",
"Idris O Sunmola",
"Andrew S Borland",
"Matthew J Carey",
"Jordan A Katine",
"Victor Lopez-Dominguez",
"Pedram Khalili Amiri"
],
"corpus_id": 234164061,
"doc_id": "234164061",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Implementation of Artificial Neural Networks Using Magnetoresistive Random Access Memory Based Stochastic Computing Units",
"venue": "IEEE Magnetics Letters",
"year": 2021
},
{
"abstract": "Spin transfer torque magnetic RAM (STT MRAM) has emerged as a promising candidate for on chip memory in future computing platforms. We present a cross layer (device circuit architecture) approach to energy efficient cache design using STT MRAM. At the device and circuit levels, we consider different genres of MTJs and bitcells, and evaluate their impact on the area, energy and performance of caches. In addition, we propose microarchitectural techniques viz. sequential cache read and partial cache line update, which exploit the non volatility of STT MRAM to further improve energy efficiency of STT MRAM caches. A detailed comparison of STT MRAM caches with SRAM based caches is also presented. Our results indicate that the proposed optimizations significantly enhance the efficiency of STT MRAM for designing lower level caches.",
"author_names": [
"Sang Phill Park",
"Sumeet Kumar Gupta",
"Niladri Narayan Mojumder",
"Anand Raghunathan",
"Kaushik Roy"
],
"corpus_id": 8159373,
"doc_id": "8159373",
"n_citations": 84,
"n_key_citations": 6,
"score": 0,
"title": "Future cache design using STT MRAMs for improved energy efficiency: Devices, circuits and architecture",
"venue": "DAC Design Automation Conference 2012",
"year": 2012
}
] |
sping coating BiVO4 | [
{
"abstract": "The performance of BiVO4 photoanodes, especially under front side illumination, is limited by the modest charge transport properties of BiVO4. Core/shell nanostructures consisting of BiVO4 coated onto a conductive scaffold are a promising route to improving the performance of BiVO4 based photoanodes. Here, we investigate photoanodes composed of thin and uniform layers of BiVO4 particles coated onto Sb doped SnO2 (Sb:SnO2) nanotube arrays that were synthesized using a sacrificial ZnO template with controllable length and packing density. We demonstrate a new record for the product of light absorption and charge separation efficiencies (eabs x esep) of ~57.3 and 58.5% under front and back side illumination, respectively, at 0.6 VRHE. Moreover, both of these high eabs x esep efficiencies are achieved without any extra treatment or intentional doping in BiVO4. These results indicate that integration of Sb:SnO2 nanotube cores with other successful strategies such as doping and hydrogen treatment can increase the performance of BiVO4 and related semiconductors closer to their theoretical potential.",
"author_names": [
"Lite Zhou",
"Yang Yang",
"Jing Zhang",
"Pratap M Rao"
],
"corpus_id": 1822136,
"doc_id": "1822136",
"n_citations": 26,
"n_key_citations": 0,
"score": 1,
"title": "Photoanode with Enhanced Performance Achieved by Coating BiVO4 onto ZnO Templated Sb Doped SnO2 Nanotube Scaffold.",
"venue": "ACS applied materials interfaces",
"year": 2017
},
{
"abstract": "Abstract This work focuses on developing a novel photoelectrocatalytic (PEC) cell combined with a solar cell for the highest efficiency, simplest process, and most energy savings to degrade organic dyes in wastewater. FTO/WO3/BiVO4 photoanode electrode fabrication was developed with the simple layer by layer dip coating method, which allows production to be scaled up in the future. The fabricated WO3/BiVO4 shows thin film properties of high porosity, good visible light absorption, and ability to cover the entire FTO substrate area. The developed FTO/WO3/BiVO4 electrode exhibits high oxidation activity and high durability, and it can be applied to the PEC cell prototype by working under the catalytic mechanism of light irradiation and bias potential for organic dye degradation. The novel PEC cell was especially designed to include a solar cell to convert light into electrical energy that is stored in batteries for potential bias at the anode electrode and to supply electricity to the light irradiated electrode and solar cell panel under the electrical circuit's controller. The result shows that the developed PEC cell prototype can operate on its own without using external power and is able to degrade methylene blue and rhodamine B dyes up to 94% and 93% in 3 h, respectively. This research provides a novel, innovative PEC cell prototype that is highly effective at removing various organic dye substances, uses a simple method, offers an energy saving process, and is a very interesting way to further a large industrial dye wastewater treatment system.",
"author_names": [
"Watcharapong Nareejun",
"Chatchai Ponchio"
],
"corpus_id": 219011914,
"doc_id": "219011914",
"n_citations": 9,
"n_key_citations": 0,
"score": 0,
"title": "Novel photoelectrocatalytic/solar cell improvement for organic dye degradation based on simple dip coating WO3/BiVO4 photoanode electrode",
"venue": "",
"year": 2020
},
{
"abstract": "Abstract The tungsten oxide (WO3) were fabricated by thermal decomposition method, with help of precursor Ammonium meta tungstate (AMT) Bismuth vanadate (BiVO4) was formed by sol gel based dip coating method. WO3/BiVO4 heterojunction, was formed by spin coating BiVO4 on WO3 surface. The number of layers in BiVO4 on WO3 coated substrate was varied. As prepared films were characterized by scanning electron microscopy (SEM) UV vis absorption, x ray diffraction (XRD) Photoelectrochemical (PEC) tests such as linear sweep voltammetry (LSV) electrochemical impendence spectroscopy (EIS) and chronoamperometeric tests were performed for WO3, BiVO4, and WO3/BiVO4 heterojunction structure. It was found that WO3/BiVO4 heterojunction produced higher photocurrent density than other photoanodes. It was also observed that the heterojunction showed an enhanced light absorption and charge separation process thus improving the overall performance of the photoelectrochemical (PEC) cell.",
"author_names": [
"S R Sitaaraman",
"M I Shanmugapriyan",
"Krishnamoorthy Varunkumar",
"Andrews Nirmala Grace",
"Raja Sellappan"
],
"corpus_id": 225225821,
"doc_id": "225225821",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Synthesis of heterojunction tungsten oxide (WO3) and Bismuth vanadate (BiVO4) photoanodes by spin coating method for solar water splitting applications",
"venue": "",
"year": 2020
},
{
"abstract": "Abstract BiVO4 nanowire array is fabricated by a hydrothermal method, and the nanowire array and a lithium foil are used as working and counter electrodes, respectively, to assemble a lithium ion battery. After charging to 4 V, the BiVO4 nanowire array has a strong oxidizing property. The pyrrole can be in situ polymerized on the surface of the charged BiVO4 nanowire array to form a polypyrrole coating layer in pyrrole solution. The morphology and structure properties of the samples are characterized and analyzed in detail. The lithium storage performances of the samples are also measured and compared. The obtained BiVO4 PPy nanowires have stable cycle performance and a discharge capacity of more than 400 mAh g 1 after 50 cycles. This work provides a new method for synthesizing conductive polymers on charged electrodes.",
"author_names": [
"Dong Fang",
"Mengmeng Cui",
"Rui Bao",
"Jian-hong Yi",
"Zhiping Luo"
],
"corpus_id": 214468053,
"doc_id": "214468053",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "In situ coating polypyrrole on charged BiVO4 nanowire arrays to improve lithium ion storage properties",
"venue": "",
"year": 2020
},
{
"abstract": "Abstract Now a days, thermochromic materials have gained the interest of scientific community because of their diverse applications. Bismuth vanadate (BiVO4) is a promising candidate for thermochromic application. In the present work, we report on the thermochromism of m BiVO4 films prepared by a modified citrate route of simple sol gel spin coating method, for the first time. X ray diffraction (XRD) study witnesses the formation of monoclinic structure of BiVO4 films. From the Raman study, the symmetric (Ag) and the anti symmetric (Bg) of V O stretching and bending modes of BiVO4 are confirmed. The highest transmittance of 95% is obtained in the near infrared region. The Urbach energy, steepness parameter and strength of electron phonon interactions are extracted from the optical data and correlated with other measurements. The films possess the petal like morphology throughout the substrate. The temperature induced reversible colour change of the films (from yellow to reddish orange) clearly demonstrates the thermochromic behaviour of BiVO4 films. This may be due to the annealing temperature induced variation in structural distortion of BiVO4 from monoclinic to tetragonal phase.",
"author_names": [
"R Vignesh",
"V P Brintha Mathy",
"G V Geetha",
"R Sivakumar",
"Chinnappa Sanjeeviraja"
],
"corpus_id": 230569720,
"doc_id": "230569720",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Temperature induced thermochromism of m BiVO4 thin films prepared by sol gel spin coating technique",
"venue": "",
"year": 2020
},
{
"abstract": "Achieving enhanced photoelectrochemical (PEC) activity and stability of a photoanode remains as a formidable challenge. In this study, a porous tannin nickel iron complex coated WO3/BiVO4 heterojun.",
"author_names": [
"Huan-huan Sun",
"Weibo Hua",
"Yueying Li",
"Jian-Gan Wang"
],
"corpus_id": 225450516,
"doc_id": "225450516",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Promoting Photoelectrochemical Activity and Stability of WO3/BiVO4 Heterojunctions by Coating a Tannin Nickel Iron Complex",
"venue": "",
"year": 2020
},
{
"abstract": "Photoelectrochemical water splitting is an environmentally benign way to store solar energy. Properties such as fast charge recombination and poor charge transport rate severely restrict the use of BiVO4 as a photoanode for photoelectrochemical water splitting and many attempts were made to improve the current performance limit of the photoanode. To address these disadvantages, a highly efficient BiVO4/Bi2S3 heterojunction was fabricated applying facial anion exchange (AE) and successive ionic layer adsorption and reaction (SILAR) The deposition of Bi2S3 on BiVO4 nanoworms by both AE and SILAR was confirmed through morphological, structural, and optical analyses. The morphological analysis indicated that Bi2S3 grown through SILAR has relatively more crystalline amorphous phase boundaries than Bi2S3 generated using the anion exchange method. The highest photocurrent density was observed for the SILAR coated Bi2S3 on BiVO4, which is three times the value of the pristine BiVO4 measured under 1 sun illumination (100 mW cm 2 with Air mass (AM) 1.5 filter) in a 0.5 M Na2SO4 electrolyte at 1.6 V vs. RHE. In addition, the deposition of Bi2S3 through AE results in a twofold higher photocurrent density compared to uncoated BiVO4. The comparison of the two cost effective AE and SILAR methods to deposit Bi2S3 on BiVO4 showed a negative shift in the flat band Mott Schottky values, which coincides with the drifted onset potential values of the current density voltage (J V) curve. Furthermore, photoelectrochemical impedance spectroscopy (PEIS) analyses and band alignment studies revealed that SILAR grown Bi2S3 creates an effective heterojunction with BiVO4, which leads to an efficient charge transfer.",
"author_names": [
"Sutripto Majumder",
"Nguyen Duc Quang",
"Chunjoong Kim",
"Dojin Kim"
],
"corpus_id": 229180268,
"doc_id": "229180268",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Anion exchange and successive ionic layer adsorption and reaction assisted coating of BiVO4 with Bi2S3 to produce nanostructured photoanode for enhanced photoelectrochemical water splitting.",
"venue": "Journal of colloid and interface science",
"year": 2020
},
{
"abstract": "Abstract Bismuth vanadate (BiVO4) has been regarded as a promising photoanode material for photoelectrochemical (PEC) water splitting owing to its low cost, and small band gap energy ~2.4 eV) However, the achieved current density of the BiVO4 photoanode remains far below its theoretical value ~7.5 mA cm 2) because of its severe surface charge recombination. Herein, a simple process is developed for preparing a new type of low cost metal organic coordination composed of tannic acid coordinated with Co ions (TACo) as an efficient cocatalyst to suppress the charge carrier recombination on BiVO4 photoanodes. For the BiVO4/TACo photoanode, a high photocurrent density of 4.8 mA cm 2 was achieved at 1.23 V (vs. reversible hydrogen electrode (RHE) AM 1.5 G) which approximately 3 fold higher than that of bare BiVO4. Systematic studies reveal that the enhanced water oxidation performance of BiVO4/TACo photoanode can be ascribed to the synergistic effect of following factors: (i) For the thermodynamic process, the photogenerated holes are directly transferred to TACo layer; (ii) For the kinetic process, the transferred holes can directly oxidied Co2+ to generate Co3+ active sites, which could directly oxidize H2O to molecular O2. This work provides a new tool kit for designing efficient water oxidation PECs.",
"author_names": [
"Tian Tian",
"Congzhao Dong",
"Xiangming Liang",
"Meie Yue",
"Yong Ding"
],
"corpus_id": 202881733,
"doc_id": "202881733",
"n_citations": 20,
"n_key_citations": 0,
"score": 0,
"title": "Enhanced photoelectrochemical water oxidation activity of BiVO4 by coating of Co phenolic networks as hole transfer and co catalyst",
"venue": "Journal of Catalysis",
"year": 2019
},
{
"abstract": "Abstract Monoclinic BiVO4 (m BiVO4) thin films were deposited on the ZnO nanorod arrays (NRAs) for constructing a core/shell composite photoanode, leading to a significantly enhanced photoelectrochemical (PEC) performance. Specifically, the ZnO/BiVO4 NRA sample displayed a photocurrent density of 2.3 mA/cm2 at 0.6 V vs. RHE under a visible light irradiation (100 mA/cm2) while the value was just 0.9 mA/cm2 for a ZnO NRA and 0.8 mA/cm2 for a BiVO4 film. The enhanced PEC activity was mainly attributed to the role of ZnO nanorods as a rapid electron transport pathway, which could be also versified by the electrochemical impedance analysis (including the Nyquist and Mott Schottky plots) Furthermore, a PEC biosensor was fabricated by using a ZnO/BiVO4 NRA photoanode, leading to an acceptable sensitivity of 450 mA*cm 2*M 1 and a detection limit of 0.11 mM, respectively.",
"author_names": [
"Xiao Huang",
"Jian Song",
"Linmeng Wang",
"Xiuquan Gu",
"Yulong Zhao",
"Yinghuai Qiang"
],
"corpus_id": 132668192,
"doc_id": "132668192",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Photoelectrochemical properties of ZnO/BiVO4 nanorod arrays prepared through a facile spin coating deposition route",
"venue": "Materials Science in Semiconductor Processing",
"year": 2019
},
{
"abstract": "Abstract Two highly thermal stable clay mineral based bismuth yellow hybrid pigments were facilely fabricated combining with precipitation and annealing processes using halloysite and kaolin, respectively. The color properties, crystalline phase, morphology, and thermal stability of hybrid pigments were studied. Incorporation of clay minerals not only greatly decreased the production cost of bismuth yellow, but also improved its color properties and thermal stability. After clay mineral based bismuth yellow hybrid pigments were introduced into polypropylene, the obtained composites exhibited the good mechanical properties compared with polypropylene and polypropylene reinforced with bismuth yellow, which was mainly attributed to the synergistic effect between clay minerals and bismuth yellow. It suggested that the as prepared bismuth yellow hybrid pigments could be simultaneously served as a promising colorant and toughening and strengthening materials to be applied in plastic. In addition, the bismuth yellow hybrid pigments also presented the outstanding flame retardancy after being coated on polyurethane foam.",
"author_names": [
"Xiaowen Wang",
"Bin Mu",
"Zhe Zhang",
"Aiqin Wang"
],
"corpus_id": 197608707,
"doc_id": "197608707",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Insights into halloysite or kaolin role of BiVO4 hybrid pigments for applications in polymer matrix and surface coating",
"venue": "Composites Part B: Engineering",
"year": 2019
}
] |
Strong coupling in a single quantum dot-semiconductor microcavity system. | [
{
"abstract": "Cavity quantum electrodynamics, a central research field in optics and solid state physics, addresses properties of atom like emitters in cavities and can be divided into a weak and a strong coupling regime. For weak coupling, the spontaneous emission can be enhanced or reduced compared with its vacuum level by tuning discrete cavity modes in and out of resonance with the emitter. However, the most striking change of emission properties occurs when the conditions for strong coupling are fulfilled. In this case there is a change from the usual irreversible spontaneous emission to a reversible exchange of energy between the emitter and the cavity mode. This coherent coupling may provide a basis for future applications in quantum information processing or schemes for coherent control. Until now, strong coupling of individual two level systems has been observed only for atoms in large cavities. Here we report the observation of strong coupling of a single two level solid state system with a photon, as realized by a single quantum dot in a semiconductor microcavity. The strong coupling is manifest in photoluminescence data that display anti crossings between the quantum dot exciton and cavity mode dispersion relations, characterized by a vacuum Rabi splitting of about 140 ueV.",
"author_names": [
"Johann Peter Reithmaier",
"Grzegorz Sek",
"Andreas Loffler",
"C Hofmann",
"Simon Kuhn",
"Stephan Reitzenstein",
"Leonid Veniaminovich Keldysh",
"Vladimir D Kulakovskii",
"Thomas L Reinecke",
"Alfred Forchel"
],
"corpus_id": 4426162,
"doc_id": "4426162",
"n_citations": 1269,
"n_key_citations": 17,
"score": 1,
"title": "Strong coupling in a single quantum dot semiconductor microcavity system",
"venue": "Nature",
"year": 2004
},
{
"abstract": "Properties of atom like emitters in cavities are successfully described by cavity quantum electrodynamics (cQED) We report on cavity quantum electrodynamics (cQED) experiments in a single quantum dot semiconductor system. CQED, which is a very active research field in optics and solid state physics, can be divided into a weak and a strong coupling regime. In case of weak coupling, the spontaneous emission rate of an atom like emitter, e.g. a single quantum dot exciton, can be enhanced or reduced compared to the value in vacuum in an irreversible emission process. In contrast, a reversible energy exchange between the emitter and the cavity mode takes place when the conditions for strong coupling are fulfilled. We investigate weak as well as strong coupling in a system based on a low density In0.3Ga 0.7As quantum dot layer placed as the active layer in a high quality planar AlAs/GaAs distributed Bragg reflector cavity grown by molecular beam epitaxy. Using electron beam lithography and deep plasma etching, micropillars with high Q factors (up to 43.000 for 4 mm diameter) were realized from the planar cavity structure. Due to the high oscillator strength of the In0.3Ga 0.7As quantum dots together with a small mode volume in high finesse micropillar cavities it is possible to observe strong coupling characterized by a vacuum Rabi splitting of 140 meV. The fabrication of high Q micropillar cavities as well as conditions necessary to realize strong coupling in the present system are discussed in detail.",
"author_names": [
"Stephan Reitzenstein",
"Grzegorz Sek",
"Andreas Loffler",
"C Hofmann",
"Simon Kuhn",
"Johann Peter Reithmaier",
"Leonid Veniaminovich Keldysh",
"Vladimir D Kulakovskii",
"Thomas L Reinecke",
"Alfred Forchel"
],
"corpus_id": 122364122,
"doc_id": "122364122",
"n_citations": 355,
"n_key_citations": 13,
"score": 0,
"title": "Strong coupling in a single quantum dot semiconductor microcavity system",
"venue": "SPIE OPTO",
"year": 2006
},
{
"abstract": "Light matter interaction on the level of single emitters and single photons has attracted significant scientific interest in recent years. Of particular interest is strong coupling of single emitters in solid state systems and its application to quantum information processing. Due to the enormous progress in semiconductor technology it has become feasible to demonstrate strong coupling of single quantum dots in high Q microcavity systems. Although it has been argued in these studies that it is very unlikely that several degenerated quantum dots contributed to the observed Rabi splitting, it was not verified that the system had one and only one emitter. In this work we present proof that the emission from a strongly coupled QD microcavity system is dominated by a single quantum emitter.",
"author_names": [
"C Hofmann",
"Stephan Reitzenstein",
"Andreas Loffler",
"Martin Kamp",
"Alfred Forchel",
"David Press",
"Stephan Gotzinger",
"Y Yamamoto"
],
"corpus_id": 8110684,
"doc_id": "8110684",
"n_citations": 281,
"n_key_citations": 1,
"score": 0,
"title": "Photon antibunching from a single quantum dot microcavity system in the strong coupling regime",
"venue": "2007 European Conference on Lasers and Electro Optics and the International Quantum Electronics Conference",
"year": 2007
},
{
"abstract": "Light matter interaction on the level of single emitters and single photons has attracted significant scientific interest in recent years. Of particular interest is strong coupling of single emitters in solid state systems and its application to quantum information processing. Due to the enormous progress in semiconductor technology it has become feasible to demonstrate strong coupling of single quantum dots in high Q microcavity systems. Although it has been argued in these studies that it is very unlikely that several degenerated quantum dots contributed to the observed Rabi splitting, it was not verified that the system had one and only one emitter. In this work we present proof that the emission from a strongly coupled QD microcavity system is dominated by a single quantum emitter.",
"author_names": [
"C Hofmann",
"Stephan Reitzenstein",
"Andreas Loffler",
"Martin Kamp",
"Alfred Forchel",
"David Press",
"Stephan Gotzinger",
"Yoshihisa Yamamoto"
],
"corpus_id": 199661076,
"doc_id": "199661076",
"n_citations": 24,
"n_key_citations": 0,
"score": 0,
"title": "Photon antibunching from a single quantum dot microcavity system in the strong coupling regime",
"venue": "",
"year": 2007
},
{
"abstract": "The behaviour of the photoluminescence spectra of a single quantum dot in a semiconductor microcavity is modeled numerically in the presence of an external and constant magnetic field. The dynamics of the density operator is calculated using the master equation in the Lindblad form for decoherence processes: spontaneous emission, losses through cavity mirrors, and dephasing. An incoherent pumping of excitons is used to feed the system. It is found in the photoluminescence spectra that for magnetic fields lower than 2 T the system is in the strong coupling regime and for magnetic fields greater than 2 T the system emits light like three independent systems. The line that uncouples faster is the s line.",
"author_names": [
"Luis E Cano",
"Paulo Sergio Soares Guimaraes",
"Alfonso A Portacio"
],
"corpus_id": 126222641,
"doc_id": "126222641",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Magnetic Field Effects for the Emission Spectra in a Microcavity Quantum Dot System",
"venue": "",
"year": 2018
},
{
"abstract": "We present a theoretical study of a quantum dot based microcavity laser where two nearly degenerate high Q modes are involved in the laser dynamics. To analyze the coupled carrier photon system we have extended a single mode microscopic semiconductor theory to the case of two modes and have also taken the crosscorrelation functions into account. Our theoretical results show that the mode which loses the mode competition exhibit super thermal photon bunching This interesting feature is traced back to mode coupling induced by the gain medium.The strong correlation between the two modes is revealed by calculation of the photon cross correlation functions.",
"author_names": [
"H A M Leymann",
"Alexander Foerster",
"Mikayel Khanbekyan",
"Jan Wiersig"
],
"corpus_id": 117726026,
"doc_id": "117726026",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Strong photon bunching in a quantum dot based two mode microcavity laser",
"venue": "",
"year": 2013
},
{
"abstract": "In spite of their different natures, light and matter can be unified under the strong coupling regime, yielding superpositions of the two, referred to as dressed states or polaritons. After initially being demonstrated in bulk semiconductors and atomic systems, strong coupling phenomena have been recently realized in solid state optical microcavities. Strong coupling is an essential ingredient in the physics spanning from many body quantum coherence phenomena, such as Bose Einstein condensation and superfluidity, to cavity quantum electrodynamics. Within cavity quantum electrodynamics, the Jaynes Cummings model describes the interaction of a single fermionic two level system with a single bosonic photon mode. For a photon number larger than one, known as quantum strong coupling, a significant anharmonicity is predicted for the ladder like spectrum of dressed states. For optical transitions in semiconductor nanostructures, first signatures of the quantum strong coupling were recently reported. Here we use advanced coherent nonlinear spectroscopy to explore a strongly coupled exciton cavity system. We measure and simulate its four wave mixing response, granting direct access to the coherent dynamics of the first and second rungs of the Jaynes Cummings ladder. The agreement of the rich experimental evidence with the predictions of the Jaynes Cummings model is proof of the quantum strong coupling regime in the investigated solid state system.",
"author_names": [
"Jacek Kasprzak",
"Stephan Reitzenstein",
"Egor A Muljarov",
"Caroline Kistner",
"Christian Schneider",
"Max Strauss",
"Sven Hofling",
"Alfred Forchel",
"Wolfgang W Langbein"
],
"corpus_id": 24118475,
"doc_id": "24118475",
"n_citations": 115,
"n_key_citations": 4,
"score": 0,
"title": "Up on the Jaynes Cummings ladder of a quantum dot/microcavity system.",
"venue": "Nature materials",
"year": 2010
},
{
"abstract": "The concept of multifunctional device (a quantum node) composed of a semiconductor single electron four level doublequantum dot coupled to an optical microcavity resonator is developed. The terahertz laser field and voltage biases provide an external control. The structure enables flexible driving via appropriate variations of field amplitudes and switching between resonant and off resonant modes. As shown this hybrid electron photon system can be used as the charge qubit with flying to stationary qubit conversion or the single photon transistor and several others. Each of listed devices works in the specific regime of system evolution. For example, the qubit is robust when the optical resonator and laser Rabi frequencies dominate the dissipation rates the so called strong coupling or coherent regime. From another hand, in order to attain the steady state one has to work in the so called weak coupling or incoherent regime when the dissipation rates are comparable to or greater than the Rabi frequencies. Further, the single photon driving is required for spectroscopic applications of this system. We numerically investigate the population dynamics to reveal the parameter choice corresponding to each device. The model is based on Lindblad formalism where all incoherent processes are considered as the markovian ones. The time dependencies of populations and spectrograms for different pairs of parameters are obtained. The specific features concerned with working characteristics of the quantum node in different modes are discussed.",
"author_names": [
"A V Tsukanov"
],
"corpus_id": 125694483,
"doc_id": "125694483",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Multifunctional quantum node based on double quantum dot in laser and cavity fields",
"venue": "International Conference on Micro and Nano Electronics",
"year": 2016
},
{
"abstract": "We investigate theoretically two photon processes in a microcavity containing one quantum dot in the strong coupling regime. The cavity mode can be tuned to resonantly drive the two photon transition between the ground and the biexciton states while the exciton states are far off resonance due to the biexciton binding energy. We study the steady state of the quantum dot and cavity field in presence of a continuous incoherent pumping. We identify the regime where the system acts as two photon emitter and discuss the feasibility and performance of realistic single quantum dot devices for two photon lasing.",
"author_names": [
"Elena del Valle",
"Stefano Zippilli",
"F Laussy",
"Alejandro Gonzalez-Tudela",
"Giovanna Morigi",
"Carlos Tejedor"
],
"corpus_id": 118868013,
"doc_id": "118868013",
"n_citations": 61,
"n_key_citations": 1,
"score": 0,
"title": "Two photon lasing by a single quantum dot in a high Q microcavity",
"venue": "",
"year": 2010
},
{
"abstract": "We have studied the Raman and luminescence spectra of a microcavity quantum dot system consisting of a melamine formaldehyde latex microsphere coated by CdTe colloidal quantum dots. The cavity induced enhancement of the Raman scattering allows the observation of Raman spectra from only a monolayer of CdTe quantum dots. Periodic structure with very narrow peaks in the luminescence spectra of a single microsphere was detected arising from the coupling between the emission from quantum dots and spherical cavity modes. Strong anti Stokes emission from CdTe quantum dots coupled to the cavity modes was observed using low intensity below band gap excitation and attributed to the strong field enhancement at the microcavity resonances.",
"author_names": [
"Yury P Rakovich",
"John F Donegan",
"Nikolai Gaponik",
"Andrey L Rogach"
],
"corpus_id": 56005060,
"doc_id": "56005060",
"n_citations": 29,
"n_key_citations": 1,
"score": 0,
"title": "Raman scattering and anti Stokes emission from a single spherical microcavity with a CdTe quantum dot monolayer",
"venue": "",
"year": 2003
}
] |
"pluck*" AND "string" | [
{
"abstract": "There are many techniques currently used for digital music synthesis, including frequency modulation (FM) synthesis, waveshaping, additive synthesis, and subtractive synthesis. To achieve rich, natural sounds, all of them require fast arithmetic capability, such as is found on expensive computers or digital synthesizers. For musicians and experimenters without access to these machines, musically interesting digital synthesis has been almost impossible. The techniques described in this paper can be implemented quite cheaply on almost any computer. Real time synthesis implementations have been done for Intel 8080A (by Alex Strong) Texas Instruments TMS9900 (by Kevin Karplus) and SC/MP (by Mike Plass) microprocessors. David Jaffe and Julius Smith have programmed the Systems Concept Digital Synthesizer at the Center for Computer Research in Music and Acoustics (CCRMA) to perform several variants of the algorithms (Jaffe and Smith 1983) Not only are the algorithms simple to implement in software, but hardware realizations are easily done. The authors have designed and tested a custom n channel metal oxide semiconductor (nMOS) chip (the Digitar chip) which computes 16 independent notes, each with a sampling rate of 20 KHz.",
"author_names": [
"Kevin Karplus",
"Alexander R Strong"
],
"corpus_id": 62673685,
"doc_id": "62673685",
"n_citations": 337,
"n_key_citations": 11,
"score": 0,
"title": "Digital Synthesis of Plucked String and Drum Timbers",
"venue": "",
"year": 1983
},
{
"abstract": "In the McGurk effect, visual information specifying a speaker's articulatory movements can influence auditory judgments of speech. In the present study, we attempted to find an analogue of the McGurk effect by using nonspeech stimuli the discrepant audiovisual tokens of plucks and bows on a cello. The results of an initial experiment revealed that subjects' auditory judgments were influenced significantly by the visual pluck and bow stimuli. However, a second experiment in which speech syllables were used demonstrated that the visual influence on consonants was significantly greater than the visual influence observed for pluck bow stimuli. This result could be interpreted to suggest that the nonspeech visual influence was not a true McGurk effect. In a third experiment, visual stimuli consisting of the wordspluck andbow were found to have no influence over auditory pluck and bow judgments. This result could suggest that the nonspeech effects found in Experiment 1 were based on the audio and visual information's having an ostensive lawful relation to the specified event. These results are discussed in terms of motor theory, ecological, and FLMP approaches to speech perception.",
"author_names": [
"Helena M Saldana",
"Lawrence D Rosenblum"
],
"corpus_id": 37554410,
"doc_id": "37554410",
"n_citations": 129,
"n_key_citations": 5,
"score": 0,
"title": "Visual influences on auditory pluck and bow judgments",
"venue": "Perception psychophysics",
"year": 1993
},
{
"abstract": "We develop techniques to compute higher loop string amplitudes for twistedN=2 theories withc=3 (i.e. the critical case) An important ingredient is the discovery of an anomaly at every genus in decoupling of BRST trivial states, captured to all orders by a master anomaly equation. In a particular realization of theN=2 theories, the resulting string field theory is equivalent to a topological theory in six dimensions, the Kodaira Spencer theory, which may be viewed as the closed string analog of the Chern Simons theory. Using the mirror map this leads to computation of the 'number' of holomorphic curves of higher genus curves in Calabi Yau manifolds. It is shown that topological amplitudes can also be reinterpreted as computing corrections to superpotential terms appearing in the effective 4d theory resulting from compactification of standard 10d superstrings on the correspondingN=2 theory. Relations withc=1 strings are also pointed out.",
"author_names": [
"Michael Bershadsky",
"Sergio Cecotti",
"Hirosi Ooguri",
"C Vafa"
],
"corpus_id": 119331715,
"doc_id": "119331715",
"n_citations": 1222,
"n_key_citations": 196,
"score": 0,
"title": "Kodaira Spencer theory of gravity and exact results for quantum string amplitudes",
"venue": "",
"year": 1994
},
{
"abstract": "In this chapter some distinct characteristics of the plucked string instruments from Asia will be discussed in relation to those from the West. Primary attention will be paid to the interrelation between the instrument wood material, the playing style, and the resulting sound. It will be demonstrated that the philosophy of making string instruments is definitely different in Asia and the Western countries.",
"author_names": [
"Shigeru Yoshikawa"
],
"corpus_id": 108618092,
"doc_id": "108618092",
"n_citations": 6,
"n_key_citations": 2,
"score": 0,
"title": "Plucked String Instruments in Asia",
"venue": "",
"year": 2010
},
{
"abstract": "We are developing systems which play music on synthesized plucked strings instruments idiomatically. The present paper introduces a system focusing on the acoustic guitar. The system is programmed with rules embodying the architecture of the guitar and the respective biomechanical constraints of a performer. These rules define the types of musical gestures that are played by the system: only those gestures that are idiomatically compatible with the guitar are performed. The system also features rules for arranging (and re arranging) musical materials in order to make them idiomatically playable. These include rules for shaping chords and algorithms for generating realistic fingering.",
"author_names": [
"Leandro Lesqueves Costalonga",
"Eduardo Reck Miranda",
"John Matthias",
"Rosa Maria Vicari"
],
"corpus_id": 6403961,
"doc_id": "6403961",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "An Idiomatic Plucked String Player",
"venue": "FLAIRS Conference",
"year": 2006
},
{
"abstract": "Digital waveguide modeling of a nonlinear vibrating string is investigated when the nonlinearity is essentially caused by tension modulation. We derive synthesis models where the nonlinearity is implemented with a time varying fractional delay filter. Also, conversion from a dual delay line physical model into a single delay loop model is explained. Realistic synthetic tones with nonlinear effects are obtained by introducing minor amendments to a linear string synthesis algorithm. It is shown how synthetic plucked string tones are modified as a consequence of tension modulation.",
"author_names": [
"Vesa Valimaki",
"Tero Tolonen",
"Matti Karjalainen"
],
"corpus_id": 843421,
"doc_id": "843421",
"n_citations": 45,
"n_key_citations": 2,
"score": 0,
"title": "Plucked string synthesis algorithms with tension modulation nonlinearity",
"venue": "1999 IEEE International Conference on Acoustics, Speech, and Signal Processing. Proceedings. ICASSP99 (Cat. No.99CH36258)",
"year": 1999
},
{
"abstract": "The physics of the plucked string has been treated in many articles and books.1 4 For our 12th grade high school physics laboratory, we have built a cheap, simple sonometer apparatus for each pair of students on which they may investigate some interesting phenomena that arise when a string is plucked. Among these are the generation of harmonics (overtones) and the way their number depends on the length of a string and on where one plucks, the relation between the frequencies of the fundamental and those of the harmonics, and the way these are affected by changes in the length and the tension in the string. Such an experiment will help students appreciate the working of stringed musical instruments and, in particular, the contribution of overtones to the richness of sound produced.",
"author_names": [
"Paul Gluck"
],
"corpus_id": 123162079,
"doc_id": "123162079",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Plucked String on a Shoestring Budget",
"venue": "",
"year": 2009
},
{
"abstract": "The exact equation of motion for a plucked flexible string is compared at second order level with the D'Alembert approximation. Important differences are demonstrated and discussed. A simplifying hypothesis is proposed.",
"author_names": [
"J E Bolwell"
],
"corpus_id": 120156742,
"doc_id": "120156742",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "How realistic is the D'Alembert plucked string?",
"venue": "",
"year": 1999
},
{
"abstract": "The audibility of variations of decay parameters in plucked string synthesis was studied by a listening test. The decay was described by an overall time constant and a frequency dependent parameter. Two fundamental frequencies, tone durations, and types of excitations were used for both parameters. The results indicate that variations between 25 and 40% in the time constant are inaudible. This suggests large perceptual tolerances for the decay parameters. The results are applied in model based audio processing.",
"author_names": [
"Hanna Jarvelainen",
"Tero Tolonen"
],
"corpus_id": 111813929,
"doc_id": "111813929",
"n_citations": 18,
"n_key_citations": 0,
"score": 0,
"title": "Perceptual Tolerances for Decay Parameters in Plucked String Synthesis",
"venue": "",
"year": 2001
},
{
"abstract": "The excitation mechanism of any musical instrument is a key component of the sound production and resulting sound of the instrument. In the case of the guitar, the manner and object with which the strings on the guitar are plucked determine, to some extent, the sound of the instrument. Parameters such as the plucking position, initial displacement, and deformation of the string have a strong influence on the resulting sound and its spectrum. In this talk, these and other parameters, as well as how they influence the sound, will be explained in detail, reviewing the studies available on this subject.",
"author_names": [
"Sandra Carral"
],
"corpus_id": 122009800,
"doc_id": "122009800",
"n_citations": 3,
"n_key_citations": 0,
"score": 1,
"title": "Plucking the string: The excitation mechanism of the guitar.",
"venue": "",
"year": 2010
}
] |
Plasmonic Coupling Architectures for Enhanced Photocatalysis | [
{
"abstract": "Plasmonic photocatalysis is a promising approach for solar energy transformation. Comparing with isolated metal nanoparticles, the plasmonic coupling architectures can provide further strengthened local electromagnetic field and boosted light harvesting capability through optimal control over the composition, spacing, and orientation of individual nanocomponents. As such, when integrated with semiconductor photocatalysts, the coupled metal nanostructures can dramatically promote exciton generation and separation through plasmonic coupling driven charge/energy transfer toward superior photocatalytic efficiencies. Herein, the principles of the plasmonic coupling effect are presented and recent progress on the construction of plasmonic coupling architectures and their integration with semiconductors for enhanced photocatalytic reactions is summarized. In addition, the remaining challenges as to the rational design and utilization of plasmon coupling structures are elaborated, and some prospects to inspire new opportunities on the future development of plasmonic coupling structures for efficient and sustainable light driven reactions are raised.",
"author_names": [
"Can Xue"
],
"corpus_id": 233382098,
"doc_id": "233382098",
"n_citations": 0,
"n_key_citations": 0,
"score": 1,
"title": "Plasmonic Coupling Architectures for Enhanced Photocatalysis.",
"venue": "Advanced materials",
"year": 2021
},
{
"abstract": "Assembling two dimensional (2D) nanomaterials into three dimensional (3D) hierarchical structures with novel functions is challenging and has attracted considerable attention. However, it is quite difficult to obtain complex 3D architectures of 2D materials with a uniform and intact structure using traditional methods, such as hydrothermal/solvothermal methods and direct precipitation methods. Here, we use butterfly wing scales as bio templates to prepare 3D hierarchical BiOCl/Au wing scales for plasmonic photocatalysis. The as prepared materials exhibit excellent photodegradation of rhodamine B (RhB) under visible light. The degradation rates of BiOCl microspheres and BiOCl and BiOCl/Au butterfly wing scales are 48.8% 72.6% and 93.8% respectively, within 20 min illumination at the same loading capacities. This excellent performance of BiOCl/Au is attributed to the coupling of enhanced carrier separation efficiency and the effect of localized surface plasmon resonance (LSPR) aroused by 3D metallic structures. This study provides a relatively facile method to obtain complex 3D constructure of 2D materials. It also demonstrates a nature led route to prepare highly efficient plasmonic photocatalysts.",
"author_names": [
"Xudong Yan",
"Huamei Zhao",
"Tengfei Li",
"Wang Zhang",
"Qinglei Liu",
"Yang Yuan",
"Lujun Huang",
"Lulu Yao",
"Jiahao Yao",
"Huilan Su",
"Yishi Su",
"Jiajun Gu",
"Di Zhang"
],
"corpus_id": 160012773,
"doc_id": "160012773",
"n_citations": 16,
"n_key_citations": 0,
"score": 0,
"title": "In situ synthesis of BiOCl nanosheets on three dimensional hierarchical structures for efficient photocatalysis under visible light.",
"venue": "Nanoscale",
"year": 2019
},
{
"abstract": "Plasmonic nanomaterials coupled with catalytically active surfaces can provide unique opportunities for various catalysis applications, where surface plasmons produced upon proper light excitation can be adopted to drive and/or facilitate various chemical reactions. A brief introduction to the localized surface plasmon resonance and recent design and fabrication of highly efficient plasmonic nanostructures, including plasmonic metal nanostructures and metal/semiconductor heterostructures is given. Taking advantage of these plasmonic nanostructures, the following highlights summarize recent advances in plasmon driven photochemical reactions (coupling reactions, O2 dissociation and oxidation reactions, H2 dissociation and hydrogenation reactions, N2 fixation and NH3 decomposition, and CO2 reduction) and plasmon enhanced electrocatalytic reactions (hydrogen evolution reaction, oxygen reduction reaction, oxygen evolution reaction, alcohol oxidation reaction, and CO2 reduction) Theoretical and experimental approaches for understanding the underlying mechanism of surface plasmon are discussed. A proper discussion and perspective of the remaining challenges and future opportunities for plasmonic nanomaterials and plasmon related chemistry in the field of energy conversion and storage is given in conclusion.",
"author_names": [
"Siwei Li",
"Peng Miao",
"Yuanyuan Zhang",
"Jie Wu",
"Bin Zhang",
"Yunchen Du",
"Xijiang Han",
"Jianmin Sun",
"Ping Xu"
],
"corpus_id": 214616486,
"doc_id": "214616486",
"n_citations": 46,
"n_key_citations": 1,
"score": 0,
"title": "Recent Advances in Plasmonic Nanostructures for Enhanced Photocatalysis and Electrocatalysis.",
"venue": "Advanced materials",
"year": 2020
},
{
"abstract": "The extension of plasmonics to materials beyond the conventional noble metals opens up a novel and exciting regime after the inspiring discovery of characteristic localized surface plasmon resonances (LSPRs) in doped semiconductor nanocrystals originating from the collective oscillations of free holes in the valence band. We herein prepare colloidal monodisperse eccentric dual plasmonic noble metal nonstoichiometric copper chalcogenide (Au@Cu2 xSe) hybrid hetero nanostructures with precisely controlled semiconductor shell size and two tunable LSPRs in both visible (VIS) and near infrared (NIR) regions associated with Au and Cu2 xSe, respectively. Through systematic evaluations of the photocatalytic performance of Au@Cu2 xSe upon sole NIR and dual VIS NIR simultaneous excitations, we are capable of unambiguously elucidating the role of plasmonic coupling between two dissimilar building blocks on the accelerated photocatalytic reactions with greater rate constants from both experimental and computational perspectives. The significantly enhanced strength of the electromagnetic field arising from efficient plasmonic coupling under the excitation of two LSPRs results in the superior activities of dual plasmonic Au@Cu2 xSe in photocatalysis. The new physical and chemical insights gained from this work provide the keystone for the rational design and construction of high quality dual or even multi plasmonic nano systems with optimized properties for widespread applications ranging from photocatalysis to molecular spectroscopies.",
"author_names": [
"Mariia Ivanchenko",
"Vida Nooshnab",
"Alline F Myers",
"Nicolas Large",
"Andrew J Evangelista",
"Hao Jing"
],
"corpus_id": 235762789,
"doc_id": "235762789",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Enhanced dual plasmonic photocatalysis through plasmonic coupling in eccentric noble metal nonstoichiometric copper chalcogenide hetero nanostructures",
"venue": "Nano Research",
"year": 2021
},
{
"abstract": "Abstract Al nanoparticles composited with TiO2 (Al NPs/TiO2) has drawn considerable attention over the years due to the localized surface plasmon resonance (LSPR) effect of Al NPs can significantly enhance the photocatalytic efficiency of TiO2. However, most of the Al NPs were obtained on Al substrates which limited its practical application. Herein, the isolated Al NPs were composited together with the TiO2 by using glutathione (GSH) as linking bridge in aqueous environment. Finite difference time domain (FDTD) simulation was used to reveal the LSPR absorption of Al NPs. The results show that the LSPR of 70 nm Al NPs have a strong coupling with the TiO2 band gap. The X ray diffraction analysis and TEM images show that our sample are pure, and the TiO2 indeed composite on the surface of Al NPs under the action of GSH ligand bridge as seen in the TEM images. This ligand bridge was further verified by the FTIR and XPS measurements. The EPR experiment indicate the OH signals of Al NPs/TiO2 are higher than that of pure TiO2 because of enhanced charge separation and transfer. The photodegradation experiment show that Al NPs/TiO2 can rapidly degrade the concentration of methylene blue (MB) to zero under UV vis light illumination in 70 min. All the above results indicate that the Al NPs can significantly enhance the photocatalytic efficiency of TiO2 which due to the LSPR effect of Al.",
"author_names": [
"Tingsong Zhang",
"Mingze Xu",
"Jinhua Li"
],
"corpus_id": 225677059,
"doc_id": "225677059",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Enhanced photocatalysis of TiO2 by aluminum plasmonic",
"venue": "",
"year": 2020
},
{
"abstract": "This work shows the enhancement of the visible photocatalytic activity of TiO2 NPs film using the localized surface plasmonic resonance of Au nanostructures. We adopted a simple yet effective surface treatment to tune the size distribution, and plasmonic resonance spectrum of Au nanostructured films on glass substrates, by hot plate annealing in air at low temperatures. A hybrid photocatalytic film of TiO2:Au is utilized to catalyse a selective photodegradation reaction of Methylene Blue in solution. Irradiation at the plasmonic resonance wavelength of the Au nanostructures provides more effective photodegradation compared to broadband artificial sunlight of significantly higher intensity. This improvement is attributed to the active contribution of the plasmonic hot electrons injected into the TiO2. The broadband source initiates competing photoreactions in the photocatalyst, so that carrier transfer from the catalyst surface to the solution is less efficient. The proposed hybrid photocatalyst can be integrated with a variety of device architectures and designs, which makes it highly attractive for low cost photocatalysis applications.",
"author_names": [
"Mohammed A Ibrahem",
"Bassam G Rasheed",
"Rahman Ismael Mahdi",
"Taha M Khazal",
"Maryam M Omar",
"Mary O'neill"
],
"corpus_id": 225759949,
"doc_id": "225759949",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Plasmonic enhanced photocatalysis reactions using gold nanostructured films",
"venue": "",
"year": 2020
},
{
"abstract": "ABSTRACT Light has emerged as a promising new reagent in chemical reactions, especially in enhancing the performance of metal nanoparticle catalysts. Certain metal nanoparticles support localized surface plasmon resonances (LSPRs) which convert incident light to strong electromagnetic fields, hot carriers, or heat for directing and improving chemical reactions. By combining plasmonically active metals with traditionally catalytic metals, bimetallic nanostructures promote simultaneous light conversion and strong molecular adsorption, expanding the library of light controlled reactions. In this review, we cover three bimetallic geometries: antenna reactor, core shell, and alloyed nanoparticle systems. Each geometry hosts its own set of intermetallic interactions which can affect the photocatalytic response. While antenna reactor systems rely exclusively on optical coupling between the plasmonic and catalytic metal to enhance reactivity, core shell and alloy architectures introduce electronic interactions in addition to optical effects. These electronic interactions usually dampen the plasmonic response but also offer the potential for enhanced reactivity and product specificity. We review both state of the art bimetallic photocatalysts as well as emerging research opportunities, including leveraging quantum effects, new computational methods to understand and predict photocatalysts, and atomic scale architecting of materials.",
"author_names": [
"Katherine Sytwu",
"Michal Vadai",
"Jennifer A Dionne"
],
"corpus_id": 189973120,
"doc_id": "189973120",
"n_citations": 29,
"n_key_citations": 0,
"score": 0,
"title": "Bimetallic nanostructures: combining plasmonic and catalytic metals for photocatalysis",
"venue": "",
"year": 2019
},
{
"abstract": "The synthesis of noble metal/semiconductor hybrid nanostructures for enhanced catalytic or superior optical properties has attracted a lot of attention in recent years. In this study, a facile and all solution processed synthetic route was employed to demonstrate an Au/ZnO platform with plasmonic enhanced UV/Vis catalytic properties while retaining strengthened luminescent properties. The visible light response of photocatalysis is supported by localized surface plasmon resonance (LSPR) excitations while the enhanced performance under UV is aided by charge separation and strong absorption. The enhancement in optical properties is mainly due to local field enhancement effect and coupling between exciton and LSPR. Luminescent characteristics are investigated and discussed in detail. Recyclability tests showed that the Au/ZnO substrate is reusable by cleaning and has a long shelf life. Our result suggests that plasmonic enhancement of photocatalytic performance is not necessarily a trade off for enhanced near band edge emission in Au/ZnO. This approach may give rise to a new class of versatile platforms for use in novel multifunctional and integrated devices.",
"author_names": [
"D R Hang",
"Sk Emdadul Islam",
"Chun-Hu Chen",
"Krishna Hari Sharma"
],
"corpus_id": 205622172,
"doc_id": "205622172",
"n_citations": 25,
"n_key_citations": 0,
"score": 0,
"title": "Full Solution Processed Synthesis and Mechanisms of a Recyclable and Bifunctional Au/ZnO Plasmonic Platform for Enhanced UV/Vis Photocatalysis and Optical Properties.",
"venue": "Chemistry",
"year": 2016
},
{
"abstract": "Solar conversion to fuels or to electricity in semiconductors using far red to near infrared (NIR) light, which accounts for about 40% of solar energy, is highly significant. One main challenge is the development of novel strategies for activity promotion and new basic mechanisms for NIR response. Mother Nature has evolved to smartly capture far red to NIR light via their intelligent systems due to unique micro/nanoarchitectures, thus motivating us for biomimetic design. Here we report the first demonstration of a new strategy, based on adopting nature's far red to NIR responsive architectures for an efficient bio inspired photocatalytic system. The system is constructed by controlled assembly of light harvesting plasmonic nanoantennas onto a typical photocatalytic unit with butterfly wings' 3D micro/nanoarchitectures. Experiments and finite difference time domain (FDTD) simulations demonstrate the structural effects on obvious far red to NIR photocatalysis enhancement, which originates from (1) Enhancing far red to NIR (700~1200 nm) harvesting, up to 25% (2) Enhancing electric field amplitude of localized surface plasmon (LSPs) to more than 3.5 times than that of the non structured one, which promotes the rate of electron hole pair formation, thus substantially reinforcing photocatalysis. This proof of concept study provides a new methodology for NIR photocatalysis and would potentially guide future conceptually new NIR responsive system designs.",
"author_names": [
"Runyu Yan",
"Min Chen",
"Hang Zhou",
"Tiancun Liu",
"Xingwei Tang",
"Kebing Zhang",
"Hanxing Zhu",
"Jinhua Ye",
"Di Zhang",
"Tongxiang Fan"
],
"corpus_id": 9851640,
"doc_id": "9851640",
"n_citations": 33,
"n_key_citations": 0,
"score": 0,
"title": "Bio inspired Plasmonic Nanoarchitectured Hybrid System Towards Enhanced Far Red to Near Infrared Solar Photocatalysis",
"venue": "Scientific reports",
"year": 2016
},
{
"abstract": "Recent studies demonstrated that aromatic amines and aromatic nitro compounds could be converted to the corresponding azo species during surface enhanced Raman experiments. It is very interesting to study the reaction mechanism for molecules that contain both an amino group and a nitro group, nitroaniline isomers. DFT calculations are applied to study the surface enhanced Raman scattering and plasmonic photocatalysis of nitroaniline isomers on silver surfaces. The normal Raman and surface Raman spectra of nitroaniline isomers are first simulated and compared with experimental results. The calculated Raman spectra of o nitroaniline (ONA) m nitroaniline (MNA) and p nitroaniline (PNA) correspond to their solid state Raman spectra. However, the simulated surface Raman spectra of nitroaniline silver complexes are significantly different from the experimental SERS spectra. According to the theoretical simulation, the appearance of new peaks in the SERS experiments of nitroaniline is attributed to the formatio.",
"author_names": [
"Liu-Bin Zhao",
"Xiao-Xiang Liu",
"De-Yin Wu"
],
"corpus_id": 98874743,
"doc_id": "98874743",
"n_citations": 11,
"n_key_citations": 0,
"score": 0,
"title": "Oxidative Coupling or Reductive Coupling? Effect of Surroundings on the Reaction Route of the Plasmonic Photocatalysis of Nitroaniline",
"venue": "",
"year": 2016
}
] |
Recent advances in memory technology | [
{
"abstract": "In the last five years we have seen remarkable advances in the density of commodity memory devices, both NAND flash and DRAM. NAND flash has now migrated to the 1x nm era, and DRAM is has reached the 2x nm node. To achieve this level of integration the manufacturers have had to adopt both new materials and processes, and also were the first users of advanced lithographic techniques such as immersion lithography and double patterning. Chipworks, as a supplier of competitive intelligence to the semiconductor and electronics industries, monitors the evolution of chip processes as they come into commercial production. Chipworks has obtained parts from the leading edge manufacturers, and performed structural analyses to examine the features and manufacturing processes of the devices. The paper reviews some of the different flash and DRAM memory structures produced recently, and looks at the details of the memory cells.",
"author_names": [
"Dick James"
],
"corpus_id": 23158979,
"doc_id": "23158979",
"n_citations": 7,
"n_key_citations": 0,
"score": 1,
"title": "Recent advances in memory technology",
"venue": "ASMC 2013 SEMI Advanced Semiconductor Manufacturing Conference",
"year": 2013
},
{
"abstract": "Computing in memory (CiM) is a popular design alternative to overcome the von Neumann bottleneck and improve the performance of artificial intelligence computing applications. Monolithic three dimensional (M3D) technology is a promising solution to extend Moore's law through the development of CiM for data intensive applications. In this article, we first discuss the motivation and challenges associated with two dimensional CiM designs, and then examine the possibilities presented by emerging M3D technologies. Finally, we review recent advances and trends in the implementation of CiM using M3D technology.",
"author_names": [
"Zhixiao Zhang",
"Xin Si",
"Srivatsa Rangachar Srinivasa",
"Akshay Krishna Ramanathan",
"Meng-Fan Chang"
],
"corpus_id": 207972583,
"doc_id": "207972583",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Recent Advances in Compute in Memory Support for SRAM Using Monolithic 3 D Integration",
"venue": "IEEE Micro",
"year": 2019
},
{
"abstract": "Emerging Non Volatile Memories (NVM) have shown enormous potential for wide applications within the memory hierarchy to replace and/or assist conventional CMOS technology. In addition to key advantages of having low leakage power and low footprint, these technologies possess unique characteristics that can be leveraged to develop secure hardware and compute capable memories. We review these unique properties of NVMs in implementing security primitives. We also present potential attacks against NVMs and their countermeasures.",
"author_names": [
"Karthikeyan Nagarajan",
"Asmit De",
"Sina Sayyah Ensan",
"Abdullah Ash-Saki",
"Mohammad Nasim Imtiaz Khan",
"Swaroop Ghosh"
],
"corpus_id": 221476274,
"doc_id": "221476274",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Recent Advances in Emerging Technology based Security Primitives, Attacks and Mitigation",
"venue": "2020 IEEE 63rd International Midwest Symposium on Circuits and Systems (MWSCAS)",
"year": 2020
},
{
"abstract": "Summary Organic fluorescent molecules have broad applications in modern technology, such as in security systems, chemosensors, bioprobes, field effect transistors, memory devices, organic light emitting diodes, etc. The transition metal catalyzed C H bond functionalization approach represents a distinct, facile, and atom efficient tactic for the construction of organic fluorescent molecules, which are often difficult to prepare using typical synthetic methods. In this review, four types of C H bond functionalization reactions for the preparation of fluorescent materials are discussed: (1) transition metal catalyzed C H/C X cross coupling reactions; (2) transition metal catalyzed C H/C H cross coupling reactions; (3) transition metal catalyzed C H addition and/or annulation reactions; and (4) transition metal catalyzed C H/C M or C H/Het H bond functionalization. The objective of this review is to characterize the current state of the art in using transition metal catalyzed C H functionalization to build fluorescent molecules as well as their application in electroluminescent materials, mechanofluorochromic materials, labels, sensors for bioimaging, etc.",
"author_names": [
"Bijin Li",
"Ahmed Ali",
"Haibo Ge"
],
"corpus_id": 224976793,
"doc_id": "224976793",
"n_citations": 12,
"n_key_citations": 0,
"score": 0,
"title": "Recent Advances in Using Transition Metal Catalyzed C H Functionalization to Build Fluorescent Materials",
"venue": "",
"year": 2020
},
{
"abstract": "Molecular imprinting technology (MIT) concerns formation of selective sites in a polymer matrix with the memory of a template. Recently, molecularly imprinted polymers (MIPs) have aroused extensive attention and been widely applied in many fields, such as solid phase extraction, chemical sensors and artificial antibodies owing to their desired selectivity, physical robustness, thermal stability, as well as low cost and easy preparation. With the rapid development of MIT as a research hotspot, it faces a number of challenges, involving biological macromolecule imprinting, heterogeneous binding sites, template leakage, incompatibility with aqueous media, low binding capacity and slow mass transfer, which restricts its applications in various aspects. This critical review briefly reviews the current status of MIT, particular emphasis on significant progresses of novel imprinting methods, some challenges and effective strategies for MIT, and highlighted applications of MIPs. Finally, some significant attempts in further developing MIT are also proposed (236 references)",
"author_names": [
"Lingxin Chen",
"Shoufang Xu",
"Jinhua Li"
],
"corpus_id": 24294354,
"doc_id": "24294354",
"n_citations": 1224,
"n_key_citations": 12,
"score": 0,
"title": "Recent advances in molecular imprinting technology: current status, challenges and highlighted applications.",
"venue": "Chemical Society reviews",
"year": 2011
},
{
"abstract": "Recent advances in emerging technologies such as monolithic 3D Integration (M3D IC) and emerging non volatile memory (eNVM) have enabled to embed logic operations in memory. This alleviates the \"memory wall\" challenges stemming from the time and power expended on migrating data in conventional Von Neumann computing paradigms. We propose a M3D SRAM dot product engine for compute in SRAM support used in applications such as matrix multiplication and artificial neural networks. In addition, we propose a novel computing in RRAM based memory architecture to efficiently solve the computation intensity of sparse dot products. Specifically, the index assessment of sparse matrix vector multiplication used in support vector machines (SVM) At maximum throughput, our proposed RRAM architecture achieves 11.3x speed up when compared against a near memory accelerator.",
"author_names": [
"Nicholas Jao",
"Srivatsa Srivinasa",
"Akshay Krishna Ramanathan",
"Minhwan Kim",
"Jack Sampson",
"Narayanan Vijaykrishnan"
],
"corpus_id": 218472594,
"doc_id": "218472594",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Technology Assisted Computing In Memory Design for Matrix Multiplication Workloads",
"venue": "2019 IEEE/ACM International Symposium on Nanoscale Architectures (NANOARCH)",
"year": 2019
},
{
"abstract": "Resistive switching devices have not only been considered as an emerging candidate for the next generation information storage technology, but also demonstrated great potential for in memory computing systems with greatly enhanced computation capability. This review focuses on the recent advances in resistive materials and devices. We first describe the electric field induced filamentary conduction model that accounts for the resistive switching behavior observed in inorganic materials, as well as the novel electric field engineering strategy that is used to optimize the device structure and the memory performance. The alternative ways of using organic and hybrid materials to construct resistive switching devices are then illustrated. By tuning the charge transfer interaction and solid state electrochemical redox properties in small molecules, polymer, metal organic framework and organic inorganic hybrid perovskite materials, bistable and multibit memories, as well as the biomimicking memristors have been fabricated. Finally, we discuss the future development of the resistive switching materials and devices, aiming to clarifying the key issues that hinders its practical applications.",
"author_names": [
"Gang Liu",
"Yu Chen",
"Shuang Gao",
"Bin Zhang",
"Run-Wei Li",
"Xiaodong Zhuang"
],
"corpus_id": 117615761,
"doc_id": "117615761",
"n_citations": 11,
"n_key_citations": 0,
"score": 0,
"title": "Recent Advances in Resistive Switching Materials and Devices: From Memories to Memristors",
"venue": "",
"year": 2018
},
{
"abstract": "Assistive technology for cognition (ATC) is technology to extend mental capacity. The majority of people reading this article will use technology to support their everyday cognitive function; by setting appointment reminders on their phone to support prospective memory, using a SatNav to support navigational skills or an search engine as an alternative to storing information in long term memory. If technology can support the cognition of ordinary individuals, potentially it can have an even greater role in assisting the cognition of people who through illness, injury or developmental disorders live with cognitive impairment. In these cases technology can act as a cognitive prosthetic or orthotic supporting or replacing lost or impaired cognitive function (Cole, Dehdashti, Petti, Angert, 1994)",
"author_names": [
"Catherine Best",
"Brian O'Neill",
"Alex Gillespie"
],
"corpus_id": 148290732,
"doc_id": "148290732",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Recent Advances in Microprompting Technology",
"venue": "",
"year": 2016
},
{
"abstract": "Stretchable field effect transistors (s FETs) an indispensable component in stretchable electronics, have emerged as a noteworthy technology in academia and industry due to their broad application prospects, especially in wearable electronics, implantable electronics and skin like electronics. Currently, significant efforts have been devoted to fabricating high performance s FETs, and remarkable advances in their material, structural, and processing techniques and applications have been achieved. Here, we summarize the recent progress in the fabrication of high performance s FETs achieved by developing advanced stretchable channel materials, structural designs and processing techniques. Moreover, the applications of s FETs in stretchable electronics, such as stretchable sensors, stretchable memory transistors and stretchable artificial neurologically devices, are discussed. Beyond discussing recent key work in this field, the current challenges and prospective directions of s FETs in stretchable electronics are also discussed. This review presents a detailed overview of the recent progress in s FET fabrication and applications, which provides a guideline for the further development of s FETs with high stretchability and electrical performance in the near future.",
"author_names": [
"Yaqian Liu",
"Qizhen Chen",
"Zhichao Rao"
],
"corpus_id": 236550204,
"doc_id": "236550204",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Recent advances in stretchable field effect transistors",
"venue": "",
"year": 2021
},
{
"abstract": "Abstract Water evaporation induced electricity generation technology has become an extremely interesting issue recently for supplying both freshwater and electricity. This review concentrates on advances in the recent development of water evaporation induced electricity generation systems for possible application in the Internet of Things, resistive switching memory, devices collecting big data. Additionally, its application in powering some small electronic devices, energy storage, electrochemical deposition and electrochemical cells are also specifically clarified in this work. We divided water evaporation induced electricity generation systems into three classifications, including tandem devices, hybrid devices, and self powered generators. The mechanism and application of each electricity generation system are also carefully discussed. Lastly, future opportunities and difficulties to develop water evaporation induced electricity generation systems are also mentioned.",
"author_names": [
"Van-Duong Dao",
"Ngoc Hung Vu",
"Hai-Linh Thi Dang",
"Sining Yun"
],
"corpus_id": 233652071,
"doc_id": "233652071",
"n_citations": 10,
"n_key_citations": 0,
"score": 0,
"title": "Recent advances and challenges for water evaporation induced electricity toward applications",
"venue": "Nano Energy",
"year": 2021
}
] |
Graphitic C3N4 based noble-metal-free photocatalyst systems: a review | [
{
"abstract": "Many reviews are written on this interesting visible light active polymeric semiconductor material, the graphitic carbon nitride (g C3N4) Yet the ever expanding volume of the ongoing research on this materials has inspired us to compile this review, especially on its nanoscale architectures of noble metal free photocatalyst systems. From the viewpoint of sustainable development, an economical photocatalyst which is made up of abundant elements e. g. C and N has a good prospect for large scale applications. Stability of the photocatalyst material under the experimental conditions is essential for its repeated usage, however, many semiconductors sought for visible light driven reaction, particularly sulfides and nitrides are in a compromising situation. However, g C3N4 has high chemical and photo stability besides its high activity under visible light irradiation. Furthermore, solely semiconductor materials have the intrinsic problem of recombination of photogenerated electron hole pairs. To overcome this problem, loading of the semiconductor with a co catalyst, usually a noble metal is a common practice for transfer of electron and thus avoiding the recombination. Development of a noble metal free photocatalyst systems is essentially important for sustainable applications. Hence, the construction of a hybrid composite structure is interesting in the separation of photogenerated charge carriers. Besides diminishing the rate of recombination, the heterostructures are constructed for harnessing a wider spectrum of sunlight. In contrast to bulk semiconductors, their nanoscale counterpart offers a larger number of active sites along with interesting electrical and optical properties. Importantly, construction of extensive junctions between nanomaterials greatly enhance the separation of charges and consequently improve their photocatalytic efficiency. Usually, the stability of materials is compromised with the reduction of size to nano level, however, g C3N4 and its nanomaterials demonstrate exceptional recycling in photocatalytic testing. One of the most important interests in controlling nanoparticle size, shape and composition is to develop noble metal free photocatalyst systems. Here in this review, we have compiled research on all the various applications of noble metal free nanoscale photocatalyst systems based on g C3N4. By the end, we conclude the research topic and put forward future perspectives for further developments in designing practicable photocatalyst systems.",
"author_names": [
"Dilshad Masih",
"Yuanyu Ma",
"Sohrab Rohani"
],
"corpus_id": 99740013,
"doc_id": "99740013",
"n_citations": 376,
"n_key_citations": 1,
"score": 1,
"title": "Graphitic C3N4 based noble metal free photocatalyst systems: A review",
"venue": "",
"year": 2017
},
{
"abstract": "As a fascinating conjugated polymer, graphitic carbon nitride (g C3N4) has become a new research hotspot and drawn broad interdisciplinary attention as a metal free and visible light responsive photocatalyst in the arena of solar energy conversion and environmental remediation. This is due to its appealing electronic band structure, high physicochemical stability, and \"earth abundant\" nature. This critical review summarizes a panorama of the latest progress related to the design and construction of pristine g C3N4 and g C3N4 based nanocomposites, including (1) nanoarchitecture design of bare g C3N4, such as hard and soft templating approaches, supramolecular preorganization assembly, exfoliation, and template free synthesis routes, (2) functionalization of g C3N4 at an atomic level (elemental doping) and molecular level (copolymerization) and (3) modification of g C3N4 with well matched energy levels of another semiconductor or a metal as a cocatalyst to form heterojunction nanostructures. The construction and characteristics of each classification of the heterojunction system will be critically reviewed, namely metal g C3N4, semiconductor g C3N4, isotype g C3N4/g C3N4, graphitic carbon g C3N4, conducting polymer g C3N4, sensitizer g C3N4, and multicomponent heterojunctions. The band structures, electronic properties, optical absorption, and interfacial charge transfer of g C3N4 based heterostructured nanohybrids will also be theoretically discussed based on the first principles density functional theory (DFT) calculations to provide insightful outlooks on the charge carrier dynamics. Apart from that, the advancement of the versatile photoredox applications toward artificial photosynthesis (water splitting and photofixation of CO2) environmental decontamination, and bacteria disinfection will be presented in detail. Last but not least, this comprehensive review will conclude with a summary and some invigorating perspectives on the challenges and future directions at the forefront of this research platform. It is anticipated that this review can stimulate a new research doorway to facilitate the next generation of g C3N4 based photocatalysts with ameliorated performances by harnessing the outstanding structural, electronic, and optical properties for the development of a sustainable future without environmental detriment.",
"author_names": [
"Wee-Jun Ong",
"Lling-Lling Tan",
"Yun Hau Ng",
"Siek-Ting Yong",
"Siang-Piao Chai"
],
"corpus_id": 206536333,
"doc_id": "206536333",
"n_citations": 3155,
"n_key_citations": 8,
"score": 0,
"title": "Graphitic Carbon Nitride (g C3N4) Based Photocatalysts for Artificial Photosynthesis and Environmental Remediation: Are We a Step Closer To Achieving Sustainability?",
"venue": "Chemical reviews",
"year": 2016
},
{
"abstract": "The production of hydrogen from water using a catalyst and solar energy is an ideal future energy source, independent of fossil reserves. For an economical use of water and solar energy, catalysts that are sufficiently efficient, stable, inexpensive and capable of harvesting light are required. Here, we show that an abundant material, polymeric carbon nitride, can produce hydrogen from water under visible light irradiation in the presence of a sacrificial donor. Contrary to other conducting polymer semiconductors, carbon nitride is chemically and thermally stable and does not rely on complicated device manufacturing. The results represent an important first step towards photosynthesis in general where artificial conjugated polymer semiconductors can be used as energy transducers.",
"author_names": [
"Xinchen Wang",
"Kazuhiko Maeda",
"Arne Thomas",
"Kazuhiro Takanabe",
"Gang Xin",
"Johan M Carlsson",
"Kazunari Domen",
"Markus Antonietti"
],
"corpus_id": 205402078,
"doc_id": "205402078",
"n_citations": 7190,
"n_key_citations": 46,
"score": 0,
"title": "A metal free polymeric photocatalyst for hydrogen production from water under visible light.",
"venue": "Nature materials",
"year": 2009
},
{
"abstract": "Semiconductor based photocatalysis is considered to be an attractive way for solving the worldwide energy shortage and environmental pollution issues. Since the pioneering work in 2009 on graphitic carbon nitride (g C3N4) for visible light photocatalytic water splitting, g C3N4 based photocatalysis has become a very hot research topic. This review summarizes the recent progress regarding the design and preparation of g C3N4 based photocatalysts, including the fabrication and nanostructure design of pristine g C3N4 bandgap engineering through atomic level doping and molecular level modification, and the preparation of g C3N4 based semiconductor composites. Also, the photo catalytic applications of g C3N4 based photocatalysts in the fields of water splitting, CO2 reduction, pollutant degradation, organic syntheses, and bacterial disinfection are reviewed, with emphasis on photocatalysis promoted by carbon materials, non noble metal cocatalysts, and Z scheme heterojunctions. Finally, the concluding remarks are presented and some perspectives regarding the future development of g C3N4 based photocatalysts are highlighted.",
"author_names": [
"Shaowen Cao",
"Jingxiang Low",
"Jiaguo Yu",
"Mietek Jaroniec"
],
"corpus_id": 5517839,
"doc_id": "5517839",
"n_citations": 2028,
"n_key_citations": 12,
"score": 0,
"title": "Polymeric photocatalysts based on graphitic carbon nitride.",
"venue": "Advanced materials",
"year": 2015
},
{
"abstract": "Sustainable hydrogen production is an essential prerequisite of a future hydrogen economy. Water electrolysis driven by renewable resource derived electricity and direct solar to hydrogen conversion based on photochemical and photoelectrochemical water splitting are promising pathways for sustainable hydrogen production. All these techniques require, among many things, highly active noble metal free hydrogen evolution catalysts to make the water splitting process more energy efficient and economical. In this review, we highlight the recent research efforts toward the synthesis of noble metal free electrocatalysts, especially at the nanoscale, and their catalytic properties for the hydrogen evolution reaction (HER) We review several important kinds of heterogeneous non precious metal electrocatalysts, including metal sulfides, metal selenides, metal carbides, metal nitrides, metal phosphides, and heteroatom doped nanocarbons. In the discussion, emphasis is given to the synthetic methods of these HER electrocatalysts, the strategies of performance improvement, and the structure/composition catalytic activity relationship. We also summarize some important examples showing that non Pt HER electrocatalysts could serve as efficient cocatalysts for promoting direct solar to hydrogen conversion in both photochemical and photoelectrochemical water splitting systems, when combined with suitable semiconductor photocatalysts.",
"author_names": [
"Xiaoxin Zou",
"Yuanchen Zhang"
],
"corpus_id": 23676252,
"doc_id": "23676252",
"n_citations": 2752,
"n_key_citations": 4,
"score": 0,
"title": "Noble metal free hydrogen evolution catalysts for water splitting.",
"venue": "Chemical Society reviews",
"year": 2015
},
{
"abstract": "Graphitic carbon nitride, g C3N4, can be made by polymerization of cyanamide, dicyandiamide or melamine. Depending on reaction conditions, different materials with different degrees of condensation, properties and reactivities are obtained. The firstly formed polymeric C3N4 structure, melon, with pendant amino groups, is a highly ordered polymer. Further reaction leads to more condensed and less defective C3N4 species, based on tri s triazine (C6N7) units as elementary building blocks. High resolution transmission electron microscopy proves the extended two dimensional character of the condensation motif. Due to the polymerization type synthesis from a liquid precursor, a variety of material nanostructures such as nanoparticles or mesoporous powders can be accessed. Those nanostructures also allow fine tuning of properties, the ability for intercalation, as well as the possibility to give surface rich materials for heterogeneous reactions. Due to the special semiconductor properties of carbon nitrides, they show unexpected catalytic activity for a variety of reactions, such as for the activation of benzene, trimerization reactions, and also the activation of carbon dioxide. Model calculations are presented to explain this unusual case of heterogeneous, metal free catalysis. Carbon nitride can also act as a heterogeneous reactant, and a new family of metal nitride nanostructures can be accessed from the corresponding oxides.",
"author_names": [
"Arne Thomas",
"Anna Fischer",
"Frederic Goettmann",
"Markus Antonietti",
"Jens Muller",
"Robert Schlogl",
"Johan M Carlsson"
],
"corpus_id": 53124927,
"doc_id": "53124927",
"n_citations": 2080,
"n_key_citations": 11,
"score": 0,
"title": "Graphitic carbon nitride materials: variation of structure and morphology and their use as metal free catalysts",
"venue": "",
"year": 2008
},
{
"abstract": "Abstract As one of the most appealing and attractive technologies, heterogeneous photocatalysis has been utilized to directly harvest, convert and store renewable solar energy for producing sustainable and green solar fuels and a broad range of environmental applications. Due to their unique physicochemical, optical and electrical properties, a wide variety of g C 3 N 4 based photocatalysts have been designed to drive various reduction and oxidation reactions under light irradiation with suitable wavelengths. In this review, we have systematically summarized the photocatalytic fundamentals of g C 3 N 4 based photocatalysts, including fundamental mechanism of heterogeneous photocatalysis, advantages, challenges and the design considerations of g C 3 N 4 based photocatalysts. The versatile properties of g C 3 N 4 based photocatalysts are highlighted, including their crystal structural, surface phisicochemical, stability, optical, adsorption, electrochemical, photoelectrochemical and electronic properties. Various design strategies are also thoroughly reviewed, including band gap engineering, defect control, dimensionality tuning, pore texture tailoring, surface sensitization, heterojunction construction, co catalyst and nanocarbon loading. Many important applications are also addressed, such as photocatalytic water splitting (H 2 evolution and overall water splitting) degradation of pollutants, carbon dioxide reduction, selective organic transformations and disinfection. Through reviewing the important state of the art advances on this topic, it may provide new opportunities for designing and constructing highly effective g C 3 N 4 based photocatalysts for various applications in photocatalysis and other related fields, such as solar cell, photoelectrocatalysis, electrocatalysis, lithium battery, supercapacitor, fuel cell and separation and purification.",
"author_names": [
"Jiuqing Wen",
"Jun Xie",
"Xiaobo Chen",
"Xin Li"
],
"corpus_id": 99039748,
"doc_id": "99039748",
"n_citations": 1341,
"n_key_citations": 4,
"score": 0,
"title": "A review on g C3N4 based photocatalysts",
"venue": "",
"year": 2017
},
{
"abstract": "Graphitic carbon nitride (g C3N4) based photocatalysts have attracted dramatically increasing interest in the area of visible light induced photocatalytic hydrogen generation due to the unique electronic band structure and high thermal and chemical stability of g C3N4. This Perspective summarizes the recent significant advances on designing high performance g C3N4 based photocatalysts for hydrogen generation under visible light irradiation. The rational strategies such as nanostructure design, band gap engineering, dye sensitization, and heterojunction construction are described. Finally, this Perspective highlights the ongoing challenges and opportunities for the future development of g C3N4 based photocatalysts in the exciting research area.",
"author_names": [
"Shaowen Cao",
"Jiaguo Yu"
],
"corpus_id": 8664316,
"doc_id": "8664316",
"n_citations": 824,
"n_key_citations": 3,
"score": 0,
"title": "g C3N4 Based Photocatalysts for Hydrogen Generation.",
"venue": "The journal of physical chemistry letters",
"year": 2014
},
{
"abstract": "To address the challenge in sustainable global development, considerable effort has been made to produce fuels from renewable resources with photocatalysts and photoelectrochemical cells (PECs) by harvesting solar energy. The solar energy conversion efficiency of photocatalysts and PECs is strongly dependent on the light absorption, charge separation, charge migration, charge recombination processes and (electro)catalytic activity in photoactive semiconductors. This perspective article describes the barrier, progress and future direction of research on the correlation of the chemical constituent, size, dimensionality, architecture, crystal structure, microstructure and electronic band structure of photocatalysts (or photoelectrodes) with five vital processes including light absorption, charge separation, migration and recombination as well as surface redox reactions. This article deals with both single materials and composites such as co catalysts on photoelectrodes/photocatalysts, dye sensitized or plasmon enhanced photocatalysts, semiconductor semiconductor heterostructures, semiconductor carbon hybrids as wells as Z scheme and tandem cells. This article also highlights the application of representative photocatalysts and PECs in solar water splitting.",
"author_names": [
"Jiangtian Li",
"Nianqiang Wu"
],
"corpus_id": 96997511,
"doc_id": "96997511",
"n_citations": 564,
"n_key_citations": 8,
"score": 0,
"title": "Semiconductor based photocatalysts and photoelectrochemical cells for solar fuel generation: a review",
"venue": "",
"year": 2015
},
{
"abstract": "Graphene, a single layer of graphite, possesses a unique two dimensional structure, high conductivity, superior electron mobility and extremely high specific surface area, and can be produced on a large scale at low cost. Thus, it has been regarded as an important component for making various functional composite materials. Especially, graphene based semiconductor photocatalysts have attracted extensive attention because of their usefulness in environmental and energy applications. This critical review summarizes the recent progress in the design and fabrication of graphene based semiconductor photocatalysts via various strategies including in situ growth, solution mixing, hydrothermal and/or solvothermal methods. Furthermore, the photocatalytic properties of the resulting graphene based composite systems are also discussed in relation to the environmental and energy applications such as photocatalytic degradation of pollutants, photocatalytic hydrogen generation and photocatalytic disinfection. This critical review ends with a summary and some perspectives on the challenges and new directions in this emerging area of research (158 references)",
"author_names": [
"Quanjun Xiang",
"Jiaguo Yu",
"Mietek Jaroniec"
],
"corpus_id": 457063,
"doc_id": "457063",
"n_citations": 2146,
"n_key_citations": 6,
"score": 0,
"title": "Graphene based semiconductor photocatalysts.",
"venue": "Chemical Society reviews",
"year": 2012
}
] |
Group 6 transition metal dichalcogenide nanomaterials: synthesis, applications and future perspectives | [
{
"abstract": "Group 6 transition metal dichalcogenides (G6 TMDs) most notably MoS2, MoSe2, MoTe2, WS2 and WSe2, constitute an important class of materials with a layered crystal structure. Various types of G6 TMD nanomaterials, such as nanosheets, nanotubes and quantum dot nano objects and flower like nanostructures, have been synthesized. High thermodynamic stability under ambient conditions, even in atomically thin form, made nanosheets of these inorganic semiconductors a valuable asset in the existing library of two dimensional (2D) materials, along with the well known semimetallic graphene and insulating hexagonal boron nitride. G6 TMDs generally possess an appropriate bandgap (1 2 eV) which is tunable by size and dimensionality and changes from indirect to direct in monolayer nanosheets, intriguing for (opto)electronic, sensing, and solar energy harvesting applications. Moreover, rich intercalation chemistry and abundance of catalytically active edge sites make them promising for fabrication of novel energy storage devices and advanced catalysts. In this review, we provide an overview on all aspects of the basic science, physicochemical properties and characterization techniques as well as all existing production methods and applications of G6 TMD nanomaterials in a comprehensive yet concise treatment. Particular emphasis is placed on establishing a linkage between the features of production methods and the specific needs of rapidly growing applications of G6 TMDs to develop a production application selection guide. Based on this selection guide, a framework is suggested for future research on how to bridge existing knowledge gaps and improve current production methods towards technological application of G6 TMD nanomaterials.",
"author_names": [
"Morasae Samadi",
"N Sarikhani",
"Mohammad Zirak",
"Hua Zhang",
"Alireza Z Moshfegh"
],
"corpus_id": 189729470,
"doc_id": "189729470",
"n_citations": 146,
"n_key_citations": 1,
"score": 1,
"title": "Group 6 transition metal dichalcogenide nanomaterials: synthesis, applications and future perspectives.",
"venue": "Nanoscale horizons",
"year": 2018
},
{
"abstract": "During recent decades, a giant leap in the development of nanotechnology has been witnessed. Numerous nanomaterials with different dimensions and unprecedented features have been developed and provided unimaginably wide scope to solve the challenging problems in biomedicine, such as cancer diagnosis and therapy. Recently, two dimensional (2D) transition metal dichalcogenide (TMDC) nanosheets (NSs) including MoS2 WS2 and etc. have emerged as novel inorganic graphene analogues and attracted tremendous attention due to their unique structures and distinctive properties, and opened up great opportunities for biomedical applications, including ultrasensitive biosensing, biological imaging, drug delivery, cancer therapy, and antibacterial treatment. A comprehensive overview of different synthetic methods of ultrathin 2D TMDC NSs and their state of the art biomedical applications, especially those that have appeared in the past few years, is presented. At the end of this review, the future opportunities and challenges for 2D TMDC NSs in biomedicine are also discussed.",
"author_names": [
"Xiao Li",
"Jingyang Shan",
"Weizhen Zhang",
"Shao Su",
"Lihui Yuwen",
"Lianhui Wang"
],
"corpus_id": 38907958,
"doc_id": "38907958",
"n_citations": 157,
"n_key_citations": 1,
"score": 0,
"title": "Recent Advances in Synthesis and Biomedical Applications of Two Dimensional Transition Metal Dichalcogenide Nanosheets.",
"venue": "Small",
"year": 2017
},
{
"abstract": "Layer structured transition metal dichalcogenide (TMDC) thin films have recently emerged as a new class of materials holding great promise as novel catalytic materials and for other electronic applications. Although many successes in the synthesis of group 6 TMDCs have been reported, the synthesis of group 5 TMDCs has rarely been investigated. In this study, we have developed a one step solution phase synthesis of group 5 TMDC films directly grown on a substrate. As example materials, we synthesized NbS2, NbSe2, VSe2, and VTe2 films directly on Si wafers. We used microwave assisted synthesis employing thermolysis of the precursors exclusively at the surface of the electrically conductive Si wafer substrate. Microwave absorption and heat loss of the substrate was experimentally and theoretically analyzed, and the microwave conditions for the synthesis are clarified. We have performed the elemental and structural analysis of the synthesized films, and investigated the growth kinetics of the synthesized films. This study paves a robust way for the synthesis of various group 5 TMDC films in solution phases.",
"author_names": [
"Junghyeok Kwak",
"Sunshin Jung",
"Noho Lee",
"Kaliannan Thiyagarajan",
"Jong Kyu Kim",
"Anupam Giri",
"Unyong Jeong"
],
"corpus_id": 139437442,
"doc_id": "139437442",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Microwave assisted synthesis of group 5 transition metal dichalcogenide thin films",
"venue": "",
"year": 2018
},
{
"abstract": "Abstract Earth abundant transition metal and metal oxide (EATM&MO) nanomaterials offer numerous positive attributes such as catalytic activity, selective enzyme mimicking catalysis, energy harvesting and storage, green chemistry and atom economy guided by size and morphology induced intrinsic properties at the nanoscale. Noble metal nanomaterials have long been played a central role and highly efficient for various electrochemical applications but their high cost and least abundance unfortunately make them less attractive towards industrial applications. In this perspective, the design and development of EATM&MO nanomaterials with unique features are imperative in the fabrication of potential electrochemical devices. This review gives an account of the various emerging synthesis of EATM&MO nanomaterials and their nanocomposites using numerous chemical strategies for the state of the art electrochemical applications. A variety of synthetic strategies for the production of diverse size morphology and composition controlled EATM&MO nanomaterials has been described for emerging applications such as sensing and biosensing, fuel cells, photovoltaics, water electrolyzer, photo electrochemical water electrolyzer, and energy storage systems (Lithium Ion Batteries, LIBs) Recent progress, important approaches, structure property relations, and future outlook towards the EATM&MO nanomaterials fabrication for diverse electrochemical devices are highlighted.",
"author_names": [
"Govindhan Maduraiveeran",
"Manickam Sasidharan",
"Wei Jin"
],
"corpus_id": 195545438,
"doc_id": "195545438",
"n_citations": 62,
"n_key_citations": 0,
"score": 0,
"title": "Earth abundant transition metal and metal oxide nanomaterials: Synthesis and electrochemical applications",
"venue": "",
"year": 2019
},
{
"abstract": "The exploration of hybridizing transition metal dichalcogenide (TMD) nanosheets with other materials as a unique approach for engineering their properties has attracted considerable attention from the scientific community for both basic studies and numerous potential applications. Among the various kinds of functional materials in hand, the utilization of intrinsically conducting polymers (CPs) in the construction of advanced hybrid composites with TMD nanosheets is considered as a fascinating approach. In this review, we aim at providing a survey of the literature on recent progress in composites based on 2D TMD and CPs. In this regard, we first discuss the different synthetic strategies used for the fabrication of two dimensional transition metal dichalcogenide/conducting polymer (2D TMD/CP) composites in detail. Subsequently, we demonstrate the state of the art advances in the utilization of these novel composites in promising applications such as energy storage, sensing devices, hydrogen production and so on. Finally, we also highlight some perspectives on the major challenges and future directions in this field of research.",
"author_names": [
"Ali Sajedi-Moghaddam",
"Esmaiel Saievar-Iranizad",
"Martin Pumera"
],
"corpus_id": 35829975,
"doc_id": "35829975",
"n_citations": 58,
"n_key_citations": 0,
"score": 0,
"title": "Two dimensional transition metal dichalcogenide/conducting polymer composites: synthesis and applications.",
"venue": "Nanoscale",
"year": 2017
},
{
"abstract": "Wearable electronic and optoelectronic devices accommodable to various mechanical deformations are becoming increasingly ubiquitous in various realms spanning electronic skins, electronic eyes, intelligent wristbands, lenses, smartphones/watches/glass, robotics, foldable screens, autonomous artificial intelligence systems, etc. which, however, are beyond the scope of conventional bulky semiconductors. Fortunately, 2D group 6 transition metal dichalcogenides (TMDCs) emerge as alternatives, having advantages of strong mechanical strength, high conformability, semitransparency, high biocompatibility, large surface to volume ratio, and favorable bandgaps. Highlighting an indispensable physical foundation for reliable wearability, this perspective begins with an elaboration on the structural and mechanical attributes of 2D TMDCs. Then, the latest research advancements of wearable electronic and optoelectronic devices built on them, including field effect transistors, gas/ion/bio/tactile sensors, photodetectors, and proof of concept novel applications, such as electronic noses, flexible displays, and the underlying working mechanisms, are compactly surveyed. This leads us to come up with the predominant challenges standing in the way of further development, and strategies addressing them, along with associated physical principles that are comprehensively outlined.Wearable electronic and optoelectronic devices accommodable to various mechanical deformations are becoming increasingly ubiquitous in various realms spanning electronic skins, electronic eyes, intelligent wristbands, lenses, smartphones/watches/glass, robotics, foldable screens, autonomous artificial intelligence systems, etc. which, however, are beyond the scope of conventional bulky semiconductors. Fortunately, 2D group 6 transition metal dichalcogenides (TMDCs) emerge as alternatives, having advantages of strong mechanical strength, high conformability, semitransparency, high biocompatibility, large surface to volume ratio, and favorable bandgaps. Highlighting an indispensable physical foundation for reliable wearability, this perspective begins with an elaboration on the structural and mechanical attributes of 2D TMDCs. Then, the latest research advancements of wearable electronic and optoelectronic devices built on them, including field effect transistors, gas/ion/bio/tactile sensors, photodetector.",
"author_names": [
"Jiandong Yao",
"Guowei Yang"
],
"corpus_id": 213117235,
"doc_id": "213117235",
"n_citations": 10,
"n_key_citations": 0,
"score": 0,
"title": "2D group 6 transition metal dichalcogenides toward wearable electronics and optoelectronics",
"venue": "",
"year": 2020
},
{
"abstract": "Recently, two dimensional transition metal dichalcogenides (2D TMDCs) have drawn certain attentions in many fields. The unique and diversified electronic structure and ultrathin sheet structure of 2D TMDCs offer opportunities for moving ahead of other 2D nanomaterials such as graphene and expanding the wide application of inorganic 2D nanomaterials in many fields. For a better understanding of 2D TMDCs, one needs to know methods for their synthesis and modification, as well as their potential applications and possible biological toxicity. Herein, we summarized the recent research progress of 2D TMDCs with particular focus on their biomedical applications and potential health risks. Firstly, two kinds of synthesis methods of 2D TMDCs, top down and bottom up, and methods for their surface functionalization are reviewed. Secondly, the applications of 2D TMDCs in the field of biomedicine, including drug loading, photothermal therapy, biological imaging and biosensor were summarized. After that, we presented the existing researches on biosafety evaluation of 2D TMDCs. At last, we discussed major research gap in current researches and challenges and coping strategies in future studies.",
"author_names": [
"Xiaofei Zhou",
"Hainan Sun",
"Xue Bai"
],
"corpus_id": 214807143,
"doc_id": "214807143",
"n_citations": 15,
"n_key_citations": 0,
"score": 0,
"title": "Two Dimensional Transition Metal Dichalcogenides: Synthesis, Biomedical Applications and Biosafety Evaluation",
"venue": "Frontiers in Bioengineering and Biotechnology",
"year": 2020
},
{
"abstract": "ABSTRACT In recent years, novel two dimensional (2D) nanomaterials are of great interest for diverse potential applications such as device fabrication, energy storage, sensing and theranostics because of their superlative physical features namely, large surface area, minimal thickness, tunable composition and easier surface modification methods. Rapid exploration in design and fabrication of 2D nano structures have opened new avenue for cancer theranostics as it can encapsulate group of cancer cells and inflict major damage with great specificity in a non invasive manner. Among the reported 2D materials such as graphene and its derivatives, metallic compounds, transition metal dichalcogenides (TMDC) black phosphorous and MXenes (e.g. carbides, nitrides, or carbonitrides) 2D nanomaterials based on graphene and TMDCs have gathered most of the limelight in this field due to their easily tunable properties. In this review, we summarize recent progress in the design of 2D theranostic nanomaterials, functionalization methods and their applications in photothermal therapy (PTT) as well as synergistic cancer therapy. We have also addressed the different modes of cellular entry of 2D nanomaterials into tumor cells based on their unique structural properties and investigated different methodologies to enhance PTT effect by optimizing the physico chemical properties of the 2D sheets. Recent progress on in vitro and in vivo short and long term biocompatibility, immunotoxicity and excretion of the decorated structure is also highlighted. Investigation of the interaction of 2D nanomaterial with hematological factors such as RBC and WBC is of paramount importance as they are key indicators in in vivo responses, and this investigation will give a better solution for overcoming direct inflammation and infection related issues of the animal system. Besides, investigations on addressing the ways to incorporate polymer linkers and drug conjugates on to the surface of 2D materials, multiplexing capability, and the influence of surface functionalization on PTT effect is vital for future developments in clinical level diagnosis and cancer therapy. Finally, we conclude our opinion on current challenges and future prospective on meeting the various demands of advanced cancer imaging and therapies. Graphical abstract Figure. No Caption available. HighlightsVarious 2D Materials for Cancer Chemo Photothermal TherapyTheory and Mechanisms of Heat Generation in 2D MaterialsSurface Modification and Functionalization of 2D MaterialsCellular Uptake Mechanisms of 2D MaterialsBiosafety and Future Challenges of 2D Materials in Cancer Therapy",
"author_names": [
"Chandran Murugan",
"Varsha Sharma",
"Rajesh Kumar Murugan",
"Gnanasekar Malaimegu",
"Anandhakumar Sundaramurthy"
],
"corpus_id": 73458602,
"doc_id": "73458602",
"n_citations": 52,
"n_key_citations": 0,
"score": 0,
"title": "Two dimensional cancer theranostic nanomaterials: Synthesis, surface functionalization and applications in photothermal therapy",
"venue": "Journal of controlled release official journal of the Controlled Release Society",
"year": 2019
},
{
"abstract": "The marked augment of drug resistance to traditional antibiotics underlines the crying need for novel replaceable antibacterials. Research advances have revealed the considerable sterilization potential of two dimension graphene based nanomaterials. Subsequently, two dimensional nanomaterials beyond graphene (2D NBG) as novel antibacterials have also demonstrated their power for disinfection due to their unique physicochemical properties and good biocompatibility. Therefore, the exploration of antibacterial mechanisms of 2D NBG is vital to manipulate antibacterials for future applications. Herein, we summarize the recent research progress of 2D NBG based antibacterial agents, starting with a detailed introduction of the relevant antibacterial mechanisms, including direct contact destruction, oxidative stress, photo induced antibacterial, control drug/metallic ions releasing, and the multi mode synergistic antibacterial. Then, the effect of the physicochemical properties of 2D NBG on their antibacterial activities is also discussed. Additionally, a summary of the different kinds of 2D NBG is given, such as transition metal dichalcogenides/oxides, metal based compounds, nitride based nanomaterials, black phosphorus, transition metal carbides, and nitrides. Finally, we rationally analyze the current challenges and new perspectives for future study of more effective antibacterial agents. This review not only can help researchers grasp the current status of 2D NBG antibacterials, but also may catalyze breakthroughs in this fast growing field.",
"author_names": [
"Linqiang Mei",
"Shuang Zhu",
"Wenyan Yin",
"Chunying Chen",
"Guangjun Nie",
"Zhanjun Gu",
"Yuliang Zhao"
],
"corpus_id": 209465901,
"doc_id": "209465901",
"n_citations": 40,
"n_key_citations": 0,
"score": 0,
"title": "Two dimensional nanomaterials beyond graphene for antibacterial applications: current progress and future perspectives",
"venue": "Theranostics",
"year": 2020
},
{
"abstract": "The intriguing properties of two dimensional transition metal dichalcogenides (2D TMDs) have led to the rapid development of research on these emerging 2D inorganic graphene like nanomaterials in various fields, such as electronic devices, sensors, catalysis, and energy storage. Recently, 2D TMDs exhibit great potentials and advantages in biological systems due to their tunable optical properties, tailorable electronic characteristics, ultrahigh surface area, versatile surface chemistry, and good biocompatibility. In this chapter, we summarize the latest progress of the use of 2D TMDs for biological applications, ranging from bioanalysis, antibacterial and wound repair, bioimaging, drug delivery, and cancer therapy to tissue engineering and medical devices. Specifically, the nanotoxicology and biosafety profiles of TMDs are reviewed to meet the concern of nanomedicine from the public and scientific community. Moreover, the current challenges and future perspectives on the development of 2D TMDs for biomedical applications are also outlined. It is expected that these promising 2D TMDs will have a great practical foundation and play an important role in next generation biomedicine.",
"author_names": [
"Linji Gong",
"Zhanjun Gu"
],
"corpus_id": 201296828,
"doc_id": "201296828",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Transition Metal Dichalcogenides for Biomedical Applications",
"venue": "",
"year": 2019
}
] |
Nanoscale Memristor Device as Synapse in Neuromorphic Systems | [
{
"abstract": "A memristor is a two terminal electronic device whose conductance can be precisely modulated by charge or flux through it. Here we experimentally demonstrate a nanoscale silicon based memristor device and show that a hybrid system composed of complementary metal oxide semiconductor neurons and memristor synapses can support important synaptic functions such as spike timing dependent plasticity. Using memristors as synapses in neuromorphic circuits can potentially offer both high connectivity and high density required for efficient computing.",
"author_names": [
"Sung-Hyun Jo",
"Ting Chang",
"Idongesit E Ebong",
"Bhavitavya Bhadviya",
"Pinaki Mazumder",
"Wei Yang Lu"
],
"corpus_id": 15097859,
"doc_id": "15097859",
"n_citations": 2785,
"n_key_citations": 86,
"score": 1,
"title": "Nanoscale memristor device as synapse in neuromorphic systems.",
"venue": "Nano letters",
"year": 2010
},
{
"abstract": "Neuromorphic systems consist of a framework of spiking neurons interconnected via plastic synaptic junctures. The discovery of a two terminal passive nanoscale memristive device has spurred great interest in the realization of memristive plastic synapses in neural networks. In this work, a synapse structure is presented that utilizes a pair of memristors, to implement both positive and negative weights. The working scheme of this synapse as an electrical interlink between neurons is explained, and the relative timing of their spiking events is analyzed, which leads to a modulation of the synaptic weight in accordance with the spike timing dependent plasticity (STDP) rule. A digital pulse width modulation technique is proposed to achieve these variable changes to the synaptic weight. The synapse architecture presented is shown to have high accuracy when used in neural networks for classification tasks. Lastly, the energy requirement of the system during various phases of operation is presented.",
"author_names": [
"Md Musabbir Adnan",
"Sagarvarma Sayyaparaju",
"Garrett S Rose",
"Catherine D Schuman",
"Bon Woong Ku",
"Sung Kyu Lim"
],
"corpus_id": 58674949,
"doc_id": "58674949",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "A Twin Memristor Synapse for Spike Timing Dependent Learning in Neuromorphic Systems",
"venue": "2018 31st IEEE International System on Chip Conference (SOCC)",
"year": 2018
},
{
"abstract": "This paper is a review paper of a promising study towards the creation of artificial synaptic networks using memristor based synapse devices and other promising research in the field of neuromorphic circuit development. In 2010, Lu et. al utilized Ag/Si memristors incorporated into crossbar synapse networks with CMOS based pre and post synaptic neurons to effectively demonstrate that changes in both pulse height and width from CMOS neurons caused corresponding changes in memductance of memristor synapse. This proved the memristor neuromorphic circuit exhibited behavior analogous to spike timing dependant plasticity, a process which governs strength of interconnects between neurons and vital to learning and memory processes. In this paper we will present overview of the memristor device, and its applications to mimic the neurological processing.",
"author_names": [
"Nathan Serafino",
"Mona E Zaghloul"
],
"corpus_id": 38699136,
"doc_id": "38699136",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "Review of nanoscale memristor devices as synapses in neuromorphic systems",
"venue": "2013 IEEE 56th International Midwest Symposium on Circuits and Systems (MWSCAS)",
"year": 2013
},
{
"abstract": "The memristive device is a nanoscale nonlinear passive two terminal fourth fundamental circuit element in addition to the three previously known passive fundamental circuit elements namely resistor, capacitor, and inductor. However aside from its non volatile memory nature, this memristor resistance/ memristance controlled in the circuit operation by the amount of charge applied between its terminals. The memristor device SPICE modeling is significant for memristive circuit and neuromorphic system design. Nowadays probabilistic switching behavior observed in many fabricated memristor devices that inspired stochastic learning rule for memristor based neuromorphic learning system application. In this paper, a stochastic metastable switch memristor model (MSSs) is used for binary weighted memristor based artificial synapse circuitry presentation. Using this MSSs memristor SPICE model a binary weighted memristor based artificial synapse circuit presented. The presented circuit shows a binary response to the signal given to the memristor implemented in the binary synaptic circuit using a stochastic memristor device model. The authors left the implementation of the proposed binary synaptic circuit in a memristor based artificial neural network that functions through the clipped perceptron (CP) learning algorithm as future work.",
"author_names": [
"Melaku Nigus",
"Rashmi Priyadarshini",
"Rakesh Mehra"
],
"corpus_id": 210995114,
"doc_id": "210995114",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Binary Weighted Synaptic Circuit for Neuromorphic Learning System Using Stochastic Memristor SPICE Model",
"venue": "2019 International Conference on Computing, Communication, and Intelligent Systems (ICCCIS)",
"year": 2019
},
{
"abstract": "The ability to vary the conductance of a valence change memristor in a continuous manner makes it a prime choice as an artificial synapse in neuromorphic systems. Because synapses are the most numerous components in the brain, exceeding the neurons by several orders of magnitude, the scalability of artificial synapses is crucial to the development of large scale neuromorphic systems but is an issue which is seldom investigated. Leveraging on the conductive atomic force microscopy method, we found that the conductance switching of nanoscale memristors ~25 nm2) is abrupt in a majority of the cases examined. This behavior is contrary to the analoglike conductance modulation or plasticity typically observed in larger area memristors. The result therefore implies that plasticity may be lost when the device dimension is scaled down. The contributing factor behind the plasticity behavior of a large area memristor was investigated by current mapping, and may be ascribed to the disruption of the plurality of conductive filaments happening at different voltages, thus yielding an apparent continuous change in conductance with voltage. The loss of plasticity in scaled memristors may pose a serious constraint to the development of large scale neuromorphic systems.",
"author_names": [
"Diing Shenp Ang",
"Y Zhou",
"Kwang Sing Yew",
"Dan Berco"
],
"corpus_id": 207977176,
"doc_id": "207977176",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "On the area scalability of valence change memristors for neuromorphic computing",
"venue": "Applied Physics Letters",
"year": 2019
},
{
"abstract": "Neuromorphic computing brainlike computing in hardware typically requires myriad CMOS spiking neurons interconnected by a dense mesh of nanoscale plastic synapses. Memristors are frequently cited as strong synapse candidates due to their statefulness and potential for low power implementations. To date, plentiful research has focused on the bipolar memristor synapse, which is capable of incremental weight alterations and can provide adaptive self organisation under a Hebbian learning scheme. In this paper we consider the Unipolar memristor synapse a device capable of switching between only two states (conductive and resistive) through application of a suitable input voltage and discuss its suitability for neuromorphic systems. A self adaptive evolutionary process is used to autonomously find highly fit network configurations. Experimentation on a dynamic reward scenario shows that unipolar memristor networks evolve task solving controllers faster than both generic bipolar memristor networks and networks containing nonplastic connections whilst performing comparably.",
"author_names": [
"Gerard David Howard",
"Larry Bull",
"Ben de Lacy Costello"
],
"corpus_id": 75670,
"doc_id": "75670",
"n_citations": 4,
"n_key_citations": 1,
"score": 0,
"title": "Evolving Unipolar Memristor Spiking Neural Networks",
"venue": "ACALCI",
"year": 2015
},
{
"abstract": "Neuromorphic computing brain like computing in hardware typically requires myriad complimentary metal oxide semiconductor spiking neurons interconnected by a dense mesh of nanoscale plastic synapses. Memristors are frequently cited as strong synapse candidates due to their statefulness and potential for low power implementations. To date, plentiful research has focused on the bipolar memristor synapse, which is capable of incremental weight alterations and can provide adaptive self organisation under a Hebbian learning scheme. In this paper, we consider the unipolar memristor synapse a device capable of non Hebbian switching between only two states (conductive and resistive) through application of a suitable input voltage and discuss its suitability for neuromorphic systems. A self adaptive evolutionary process is used to autonomously find highly fit network configurations. Experimentation on two robotics tasks shows that unipolar memristor networks evolve task solving controllers faster than both bipolar memristor networks and networks containing constant non plastic connections whilst performing at least comparably.",
"author_names": [
"Gerard David Howard",
"Larry Bull",
"Ben de Lacy Costello"
],
"corpus_id": 2638023,
"doc_id": "2638023",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Evolving unipolar memristor spiking neural networks",
"venue": "Connect. Sci.",
"year": 2015
},
{
"abstract": "Modeling and related characterization of memristive neurodynamic systems becomes a critical pathway towards neuromorphic system designs. This paper presents a general class of memristive neural networks with time varying delays. Some improved algebraic criteria for global exponential stability of memristive neural networks are obtained. The criteria improve some previous results and are easy to be verified with the physical parameters of system itself. The proposed framework for theoretical analysis of memristive neurodynamic systems may be useful in developing nanoscale memristor device as synapse in neuromorphic computing architectures.",
"author_names": [
"Ailong Wu",
"Zhigang Zeng"
],
"corpus_id": 62706645,
"doc_id": "62706645",
"n_citations": 20,
"n_key_citations": 3,
"score": 0,
"title": "Improved conditions for global exponential stability of a general class of memristive neural networks",
"venue": "Commun. Nonlinear Sci. Numer. Simul.",
"year": 2015
},
{
"abstract": "Memristors are nanoscale devices that have recently been proposed for use as a synapse in brain inspired computing systems. In this paper, we present a synapse architecture that utilizes two memristors to implement a non volatile synaptic weight that can be configured as both positive and negative. The weight of the proposed synapse has an inherent exponential like dependence on the change in the memristance of the devices, a property that we have capitalized to implement spike timing dependent plasticity (STDP) for on chip learning in spiking neural networks. We discretize the neuron's spike in time and voltage and show that learning rate can be controlled by the clock frequency used. We show that by modulating the duty cycle of the clock, we can alleviate the detrimental effects of switching rate mismatch in the devices. We also simulated a 3 x 3 crossbar structure and presented the weight updates observed therein, hence demonstrating the feasibility of a crossbar with our synapse. We evaluated the energy consumption per spike of our approach and compared it with those in literature.",
"author_names": [
"Sagarvarma Sayyaparaju",
"Sherif Amer",
"Garrett S Rose"
],
"corpus_id": 13721445,
"doc_id": "13721445",
"n_citations": 6,
"n_key_citations": 1,
"score": 0,
"title": "A bi memristor synapse with spike timing dependent plasticity for on chip learning in memristive neuromorphic systems",
"venue": "2018 19th International Symposium on Quality Electronic Design (ISQED)",
"year": 2018
},
{
"abstract": "Abstract The nanoscale memristor device SPICE modeling is significant for memristive circuits and neuromorphic system design applications. In this paper, a novel modified piece wise linear (PWL) window function proposed for the nonlinear property of the memristor SPICE model. The PWL window function used here can address the shortcoming of the parabola and Heaviside step function based typical window functions proposed in the literature, those are established by symmetrical functions. However, in most of the typical window functions, the monotonically increasing and the asymmetrical functions have not been addressed. Also, using this PWL window function based memristor model, a binary weighted memristor based artificial synaptic circuit has been designed. The performance of the device model demonstrated by the efficiency of designed artificial synapse sensitivity to the external input signal.",
"author_names": [
"Melaku Nigus Getachew",
"Rashmi Priyadarshini",
"R M Mehra"
],
"corpus_id": 213385890,
"doc_id": "213385890",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "SPICE model of HP memristor using PWL window function for neuromorphic system design application",
"venue": "",
"year": 2020
}
] |
k⋅p method for strained wurtzite semiconductors | [
{
"abstract": "We derive the effective mass Hamiltonian for wurtzite semiconductors, including the strain effects. This Hamiltonian provides a theoretical groundwork for calculating the electronic band structures and optical constants of bulk and quantum well wurtzite semiconductors. We apply Kane's model to derive the band edge energies and the optical momentum matrix elements for strained wurtzite semiconductors. We then use the k\\ensuremath{\\cdot}p perturbation method to derive the effective mass Hamiltonian, which is then checked with that derived using an invariant method based on the Pikus Bir model. We obtain the band structure \\mathit{A}}_{\\mathit{i} parameters in the group theoretical model explicitly in terms of the momentum matrix elements. We also find the proper definitions of the important physical quantities used in both models and present analytical expressions for the valence band dispersions, the effective masses, and the interband optical transition momentum matrix elements near the band edges, taking into account the strain effects. \\textcopyright{ 1996 The American Physical Society.",
"author_names": [
"Shun Lien Chuang",
"C S Chang"
],
"corpus_id": 122389650,
"doc_id": "122389650",
"n_citations": 848,
"n_key_citations": 40,
"score": 1,
"title": "k.p method for strained wurtzite semiconductors",
"venue": "",
"year": 1996
},
{
"abstract": "Calculations of the electronic properties of AIN, GaN, InN and their alloys are presented. Initial calculations are performed using the first principles pseudopotenial method to obtain accurate lattice constants. Further calculations then investigate bonding in the nitrides through population analysis and density of state calculations, the empirical pseudopotential method is also used in this work. Pseudopotentials 'or each of the nitrides are constructed using a functional form that allows strained material and alloys to be studied. The conventional k,p valence band parameters for both zincblende and wurtzite are obtained from the empirical band structure using two different methods. A Monte Carlo fitting of the k.p band structure to the pseudopotential data (or an effective mass method for the zincblende structure) is used to produce one set. Another set is obtained directly from the momentum matrix elements and energy eigenvalues at the centre of the Brillouin zone. Both methods of calculating k.p parameters produce band structure in excellent agreement with the original empirical band calculations near the centre of the Brillouin zone. The advantage of the direct method is that it produces consistent sets of parameters, and can be used in studies involving a series of alloy compositions. Further empirical pseudopotential method calculations are then performed for alloys of the nitrides. In particular, the variation of the band gap with alloy composition is investigated, and good agreement with theory and experiment is found. The direct method is used to obtain k.p parameters for the alloys, and is contrasted with the fitting approach. The behaviour of the nitrides under strain is also studied. In particular, valence band offsets for nitride heterojunctions are calculated, and a strong forward backward asymmetry in the band offset is found, in good agreement with other results in the literature.",
"author_names": [
"D J David"
],
"corpus_id": 137003732,
"doc_id": "137003732",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Electronic structure calculations on nitride semiconductors and their alloys",
"venue": "",
"year": 2000
},
{
"abstract": "The full zone kp method of band structure calculation is extended to crystals of wurtzite structure, point group C6v. The form of the momentum matrix elements as allowed by symmetry is deduced and used to model the dispersion relations throughout the Brillouin zone for AlN, GaN, and InN. By means of a fitting procedure that refers to an empirical pseudopotential calculation of the eigenvalues at selected high symmetry points, a truncated basis set of 23 states is derived that enables realistic representation of the first ten states, with the remainder serving to encompass all of the deleted remote band interactions. The result is a relatively small dimension effective Hamiltonian suitable for full zone envelope function applications.",
"author_names": [
"Roderic Beresford"
],
"corpus_id": 123048598,
"doc_id": "123048598",
"n_citations": 17,
"n_key_citations": 0,
"score": 0,
"title": "Full zone kp method of band structure calculation for wurtzite semiconductors",
"venue": "",
"year": 2004
},
{
"abstract": "We present a theoretical model for calculating the band structures of strained quantum well wurtzite semiconductors. The theory is based on the Hamiltonian for wurtzite semiconductors and includes the strain effects on the shifts of the band edges. We show new results that include the matrix elements of the Hamiltonian using the finite difference method for the calculations of the valence electronic band structures of quantum well wurtzite semiconductors based on the effective mass theory.",
"author_names": [
"Shun Lien Chuang",
"C S Chang"
],
"corpus_id": 95493795,
"doc_id": "95493795",
"n_citations": 261,
"n_key_citations": 11,
"score": 0,
"title": "A band structure model of strained quantum well wurtzite semiconductors",
"venue": "",
"year": 1997
},
{
"abstract": "A simple theoretical method for deducing the effective bond orbital model (EBOM) of III nitride wurtzite (WZ) semiconductors is presented. In this model, the interaction parameters for zinc blende (ZB) structures are used as an initial guess for WZ structure based on the two center approximation. The electronic band structure of III nitride WZ semiconductors can hence be produced by utilizing this set of parameters modified to include effects due to three center integrals and fitting with first principles calculations. Details of the semi empirical fitting procedure for constructing the EBOM Hamiltonian for bulk III nitride WZ semiconductors are presented. The electronic band structure of bulk AlN, GaN, and InN with WZ structure calculated by EBOM with modified interaction parameters are shown and compared to the results obtained from density functional (DFT) theory with meta generalized gradient approximation (mGGA) The set of parameters are further optimized by using a genetic algorithm. In the end, electronic band structures and electron (hole) effective masses near the zone center calculated by the proposed model with best fitting parameters are analyzed and compared with the \\mathbf{k}\\cdot \\mathbf{p} model.",
"author_names": [
"Fu Chen Hsiao",
"Ching-Tarng Liang",
"Yia-Chung Chang",
"John M Dallesasse"
],
"corpus_id": 102945556,
"doc_id": "102945556",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Effective bond orbital model of III nitride wurtzite structures based on modified interaction parameters of zinc blende structures",
"venue": "Comput. Phys. Commun.",
"year": 2020
},
{
"abstract": "A systematic numerical investigation of spin orbit fields in the conduction bands of III V semiconductor nanowires is performed. Zinc blende InSb nanowires are considered along [001] [011] and [111] directions, while wurtzite InAs nanowires are studied along [0001] and [10$\\overline{1}$0] or [11$\\overline{2}$0] directions. Realistic multiband \\vec{k} \\cdot \\vec{p} Hamiltonians are solved by using plane wave expansions of real space parameters. In all cases the linear and cubic spin orbit coupling parameters are extracted for nanowire widths from 30 to 100 nm. Typical spin orbit energies are on the \\mu$eV scale, except for InAs wurtzite nanowires grown along [10$\\overline{1}$0] or [11$\\overline{2}$0] in which the spin orbit energy is about meV, largely independent of the wire diameter. Significant spin orbit coupling is obtained by applying a transverse electric field, causing the Rashba effect. For an electric field of about 4 mV/nm the obtained spin orbit energies are about 1 meV for both materials in all investigated growth directions. The most favorable system, in which the spin orbit effects are maximal, are InAs WZ nanowires grown along [1010] or [11$\\overline{2}$0] since here spin orbit energies are giant (meV) already in the absence of electric field. The least favorable are InAs WZ nanowires grown along [0001] since here even the electric field does not increase the spin orbit energies beyond 0.1 meV. The presented results should be useful for investigations of optical orientation, spin transport, weak localization, and superconducting proximity effects in semiconductor nanowires.",
"author_names": [
"Tiago de Campos",
"Paulo E Faria Junior",
"Martin Gmitra",
"Guilherme Matos Sipahi",
"Jaroslav Fabian"
],
"corpus_id": 118923673,
"doc_id": "118923673",
"n_citations": 19,
"n_key_citations": 0,
"score": 0,
"title": "Spin orbit coupling effects in zinc blende InSb and wurtzite InAs nanowires: realistic calculations with multiband \\vec{k} \\cdot \\vec{p} method",
"venue": "",
"year": 2018
},
{
"abstract": "Using the effective mass Hamiltonian for an arbitrary direction wurtzite semiconductor on the basis of kp theory, we investigate the strain effects on the optical anisotropy in semi polar and nonpolar GaN planes. The optical matrix elements are formulated for an arbitrary direction and calculated for the A and R planes. It is found that giant optical anisotropy appears in the A and R planes and the biaxial strain significantly changes the polarization properties.",
"author_names": [
"Guo-Dong Hao",
"Ying-fei Chen"
],
"corpus_id": 122789181,
"doc_id": "122789181",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "IN PLANE OPTICAL ANISOTROPY OF STRAINED WURTZITE GaN IN THE A AND R PLANES",
"venue": "",
"year": 2010
},
{
"abstract": "The problem of spin manipulation via the spin orbit interaction in nonmagnetic semiconductors in the absence of magnetic fields is investigated in this work. We begin with a review of the literature on spin dynamics in semiconductors, then discuss the semi empirical k p method of calculating direct gap semiconductor properties, which we use to estimate material parameters significant for manipulation of spin even in the absence of a magnetic field. The total effective magnetic fields and precession lengths are calculated for a variety of quantum well orientations, and a class of devices are proposed that will allow for all electric arbitrary manipulation of spin orientations. The strainand momentum dependent spin splitting coefficient C3 has been calculated using a fourteen band Kane k *p model for a variety of III V semiconductors as well as ZnSe and CdSe. It is observed that the spin splitting parameters C3 and g, corresponding to the strain induced spin orbit interaction and Dresselhaus coefficient, are sensitive to the value of the inter band spin orbit coupling between the p valence and p second conduction band in all cases. The value of has therefore been recalculated in these materials using a tight binding model and modern experimental values of the valence and second conduction band spin orbit splittings. The total effective magnetic field and precession length of spins in strained quantum wells in the (001) (110) and (111) planes are derived with consideration for all known effective magnetic fields except those due to interface effects in noncommon atom heterostructures (native inversion asymmetry) The orientation of the k linear Dresselhaus field and the strain dependent fields vary strongly with the growth axis of the quantum well. The precession length in the (110) and (001) cases can achieve infinite anisotropy, while the precession length of (111) quantum wells is",
"author_names": [
"B J Moehlmann"
],
"corpus_id": 91687374,
"doc_id": "91687374",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Spin transport in strained non magnetic zinc blende semiconductors",
"venue": "",
"year": 2012
},
{
"abstract": "Abstract The electronic band structure of wurtzite semiconductor heterostructures is investigated theoretically using the envelope function k P formalism. We use a Lagrangian formulation for the valence bands so that the order of the derivatives appearing in the multiband description is explicitly specified when Schrodinger's equations for the envelope functions are generated through the application of the principle of least action. The issues of derivative operator ordering and boundary conditions at material interfaces are examined in detail. The theoretical results are presented for arbitrary growth directions and the spin orbit interaction is taken into account. This is of interest, for example, in treating A plane wurtzite heterostructures such as GaN/AlGaN quantum wells grown on R plane sapphire. Strain effects are included using a general rotation method that diagonalizes strain and is appropriate for pseudomorphic wurtzite structures in any allowed orientation. It is shown that inversion asymmetry in the valence band leads to shifts in the band edge energies in the 11 2 0 grown quantum wells. The finite element method is used with the Lagrangian for the composite layered semiconductor structure in order to obtain the energy eigenvalues for multi quantum well systems. Calculations for quantum wells and superlattices are presented.",
"author_names": [
"L R Ram-Mohan",
"A Girgis",
"John D Albrecht",
"Cole W Litton"
],
"corpus_id": 122179673,
"doc_id": "122179673",
"n_citations": 9,
"n_key_citations": 0,
"score": 0,
"title": "Wavefunction engineering of layered wurtzite semiconductors grown along arbitrary crystallographic directions",
"venue": "",
"year": 2006
},
{
"abstract": "Abstract The bond orbital Hamiltonian for wurtzite semiconductors is developed. This method contains no fitting parameters, and all interaction parameters involved are directly related to the k p parameters for describing bulk bands near the Brillouin zone center. A comparative study of wurtzite GaN band structures between the bond orbital model and the k p method is also made.",
"author_names": [
"Chun-Nan Chen"
],
"corpus_id": 121219611,
"doc_id": "121219611",
"n_citations": 4,
"n_key_citations": 1,
"score": 0,
"title": "Bond orbital model for wurtzite semiconductors",
"venue": "",
"year": 2004
}
] |
quantum confined stark effect | [
{
"abstract": "This paper reviews current technological developments in polarization engineering and the control of the quantum confined Stark effect (QCSE) for InxGa1 xN based quantum well active regions, which are generally employed in visible LEDs for solid state lighting applications. First, the origin of the QCSE in III N wurtzite semiconductors is introduced, and polarization induced internal fields are discussed in order to provide contextual background. Next, the optical and electrical properties of InxGa1 xN based quantum wells that are affected by the QCSE are described. Finally, several methods for controlling the QCSE of InxGa1 xN based quantum wells are discussed in the context of performance metrics of visible light emitters, considering both pros and cons. These strategies include doping control, strain/polarization field/electronic band structure control, growth direction control, and crystalline structure control.",
"author_names": [
"Jae-Hyun Ryou",
"P Douglas Yoder",
"Jianping Liu",
"Zachary Lochner",
"Hyunsoo Kim",
"Suk Choi",
"Hee Jin Kim",
"Russell D Dupuis"
],
"corpus_id": 36455639,
"doc_id": "36455639",
"n_citations": 224,
"n_key_citations": 9,
"score": 1,
"title": "Control of Quantum Confined Stark Effect in InGaN Based Quantum Wells",
"venue": "IEEE Journal of Selected Topics in Quantum Electronics",
"year": 2009
},
{
"abstract": "Electro optical effects, such as the Franz Keldysh effect in bulk materials or the quantum confined Stark effect in quantum well structures, lead to strong optoelectronic nonlinearities which form the basis for optical modulators and optically bistable devices. They result from a modification of the optical absorption properties by an applied electric field and are particularly pronounced in the case of low dimensional semiconductors. We review theoretical modelling and computer simulations of such optoelectronic devices in particular for ZnSe based quantum well structures, where excitonic features dominate even at room temperature. The field dependent absorption spectra are calculated by a many body theory including the full electron electron interaction. The transition from the quantum confined Stark effect, which is found for well widths smaller than the exciton Bohr diameter, to the Franz Keldysh effect, which corresponds to the limit of wide wells, is studied. Optical bistability and switching is found in R SEED and D SEED configurations, and the optimization of the device performance is discussed. 85.60.Bt, 42.65.Pc, 78.66.Hf",
"author_names": [
"Eckehard Scholl"
],
"corpus_id": 54623675,
"doc_id": "54623675",
"n_citations": 5,
"n_key_citations": 0,
"score": 1,
"title": "Modelling of devices for optoelectronic applications: The quantum confined Stark effect and self electrooptic effect devices",
"venue": "",
"year": 1999
},
{
"abstract": "The present work is motivated by the tremendous interest in the semiconductor nanostructures. The study of the quantum confined Stark effect (QCSE) in semiconductor superlattices and semiconductor quantum wells has attracted a lot of attention, as it is important both for fundamental physics and in devices for optoelectronic applications. The present paper is a brief review of the main electronic properties, which are the basis for the QCSE device applications of semiconductor superlattices and semiconductor quantum wells.",
"author_names": [
"Stark Effect"
],
"corpus_id": 209493263,
"doc_id": "209493263",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "ON THE MAIN APPLICATION PROPERTIES OF THE QUANTUM CONFINED",
"venue": "",
"year": 2017
},
{
"abstract": "G. D. Sanders et al. J. Vac. Sci. Technol. B, vol. 5, No. 4, Jul/Aug. 1987, \"Theory of Electroabsorption pp. 1295 1299. T. Hiroshima et al. J. Appl. Phys, vol. 62, No. 8, Oct. 1987, \"Quantum Confined Stark pp. 3360 3365. Y. J. Chen et al. Phys. Review B. vol. 36, No. 8, Sep. 15, 1987, \"Effect of Electric Fields.\" pp. 4562 4565. K. Nishi et al. Appi. Phys. Lett. vol. 51, No. 5, Aug. 3, 1987, \"Enhancement of Quantum Confined pp. 320 322. M. N. Islam et al. Appl. Phys. Lett. vol. 50, No. 16,",
"author_names": [
"Keith W Goossen",
"Matawan David",
"A Miller"
],
"corpus_id": 54805204,
"doc_id": "54805204",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "United States Patent 19 Goossen et al 54 SELF ELECTROOPTIC EFFECT DEVICE EMPLOYING ASYMMETRIC QUANTUM",
"venue": "",
"year": 2017
},
{
"abstract": "Germanium/Silicon Germanium (Ge/SiGe) multiple quantum wells receive great attention for the realization of Si based optical modulators, photodetectors, and light emitters for short distance optical interconnects on Si chips. Ge quantum wells incorporated between SiGe barriers, allowing a strong electro absorption mechanism of the quantum confined Stark effect (QCSE) within telecommunication wavelengths. In this review, we respectively discuss the current state of knowledge and progress of developing optical modulators, photodetectors, and emitters based on Ge/SiGe quantum wells. Key performance parameters, including extinction ratio, optical loss, swing bias voltages, and electric fields, and modulation bandwidth for optical modulators, dark currents, and optical responsivities for photodetectors, and emission characteristics of the structures will be presented.",
"author_names": [
"Papichaya Chaisakul",
"V Vakarin",
"Jacopo Frigerio",
"Daniel Chrastina",
"Giovanni Isella",
"Laurent Vivien",
"Delphine Marris-Morini"
],
"corpus_id": 127557781,
"doc_id": "127557781",
"n_citations": 17,
"n_key_citations": 0,
"score": 0,
"title": "Recent Progress on Ge/SiGe Quantum Well Optical Modulators, Detectors, and Emitters for Optical Interconnects",
"venue": "Photonics",
"year": 2019
},
{
"abstract": "Electroabsorptio Abstract Electroabsorption near the optical absorption edge of quantum well materials is interesting both for physics and applications. We briefly summarize the physical mechanisms involved (e.g. the quantum confined Stark effect) and the applications to optical modulators and switching devices. Quantum wells have recently become increasingly interesting for their optical properties, especially those associated with the remarkable excitonic absorption resonances near the optical absorption edge. One particular area of interest is in the changes in optical properties that can be induced by static electric fields; this is interesting both for the physical mechanisms involved, some of which are unique to quantum wells, and also the possibility of practical applications. The activity in both physics and applications of these other quantum well optical effects has been documented in a number of recent review articles'\" and in some extensive journal articles, and we will not attempt to duplicate these here. Instead, we will present only a brief summary of some key topics and refer the reader to other longer articles for more detailed information. Because the layered structure of quantum wells quantum confines the carriers, the optical absorption spectrum breaks up into a series of steps. In addition, however, sharp peaks (the exciton absorption resonances) appear at the edges of the steps. These peaks are much stronger than those observed in the corresponding bulk materials, and can consequently be observed at room temperature. This strength is a direct consequence of the confinement (see e.g. Ref. 5 for a discussion) These peaks also show a number of interesting nonlinear optical effects associated with absorption saturation .415 AS for changes in optical properties associated with electric fields, there are obviously two distinct directions in which the electric field can be applied, i.e. parallel to the layers and perpendicular to the layers. For fields parallel to the layers, the resulting changes in the optical absorption near to the band gap energy are qualitatively similar to those seen in bulk direct gap semiconductors at low temperature; the exciton peaks broaden and disappear with field because the exciton is rapidly field ionized, leading to a life time broadening of the resonance.6 The fact that this phenomenon can be clearly observed in quantum wells at room temperature has made it feasible to perform very high speed tests of the speed of this electroabsorption, with response 500 fs observed,7 the fastest electroabsorption ever reported to our knowledge. For perpendicular field, the behavior is quite different; the peaks are not strongly broadened with field, and the lowest peaks shift to lower energy by substantial amounts. This effect can be understood through a mechanism called the quantum confined Stark effect (QCSE).6/8 m this case, the field ionization is suppressed by the walls of the quantum well, and very large Stark shifts of the exciton are possible without large broadening. In the limit where the excitonic effects are neglected, the resulting shifts reduce to the sum of the shifts of the single particle electron and hole shifts resulting from the skewing of the quantum well by the applied field. It is, however, important to remember that it is the persistence of the exciton resonance that gives the QCSE much of its practical interest and that enables us to resolve the shift at all. As the peaks shift, they lose some strength because the overlap of electron and hole is reduced as they are pulled apart by the field. Both the shifts*'deg and the overlap^ are in good agreement with theory. The strength lost by the allowed transitions is picked up by the appearance of forbidden transitions,9 which leads to the sum rules for the quantum well electroabsorption.9 The forbidden transitions are also important in linking the QCSE to bulk electroabsorption;10 in the simplifying approximation in which the excitonic effects are neglected (an approximation that we can refer to as the quantum confined Franz Keldysh approximation) it can be shown that the QCSE is the quantum confined limit of the Franz Keldysh electroabsorption of bulk semiconductors.",
"author_names": [
"D A B Miller"
],
"corpus_id": 103516599,
"doc_id": "103516599",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Quantum wells have recently become increasingly",
"venue": "",
"year": 2017
},
{
"abstract": "D. A. B. Miller et al. Physical Review Letters, vol. 53, No. 22, Nov. 26, 1984, \"Band Edge Electroabsorption in Quantum Well Structures: The Quantum Confined Stark Effect,\" pp. 2173 2176. Y. Silberberg et al. Applied Physics Letters, vol. 46, No. 8, Apr. 15, 1985, \"Fast Nonlinear Optical Response from Proton Bombarded Multiple Quantum Well Structure, pp. 701 703. M. Wegener et al. Applied Physics Letters, vol. 55, No. 6. Aug. 7, 1989, \"Electroabsorption and Refraction by 73 Assignee:",
"author_names": [
"Firm-Gregory C Ranieri"
],
"corpus_id": 199371099,
"doc_id": "199371099",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Fast Nonlinear Optical Response from Proton Bombarded Multiple Quantum Well Structure",
"venue": "",
"year": 2017
},
{
"abstract": "In this chapter we overview recent achievements in the synthesis and investigation of optical properties of the new type of quantum sized semiconductor nanocrystals 2D nanoplatelets. Thin, atomically flat AIIBVI nanoplatelets prepared by colloidal chemistry routes are good model objects for studying optical properties of 2D semiconductor structures. Due to their discrete thickness, nanoplatelets exhibit spectrally narrow excitonic optical transitions in absorption and photoluminescence. Large lateral size of semiconductor nanoplatelets results in very efficient light absorption with the molar absorption coefficient an order of magnitude greater than that of 0D quantum dots and 1D nanorods. Sharp excitonic absorption bands of CdSe nanoplatelets allow observation of large electro optical Quantum Confined Stark effect which is much stronger than in the corresponding nanorods, or quantum dots. Besides binary core CdSe, CdS, CdTe nanoplatelets, more complex CdSe/CdS core shell and unique core wings CdSe CdS, CdSe CdTe and CdTe CdSe heteronanoplatelets with type I and type II optical transitions and bright photoluminescence can be synthesized. This expands the field of potential practical applications of nanoplatelets as efficient light convertors and fluorescent markers even further.",
"author_names": [
"Artsiom Antanovich",
"Anatol V Prudnikau",
"Mikhail V Artemyev"
],
"corpus_id": 138701225,
"doc_id": "138701225",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Optical Properties of Semiconductor Colloidal Quantum Wells",
"venue": "",
"year": 2016
},
{
"abstract": "Vertical cavity surface emitting lasers (VCSELs) are promising in various applications including full color mobile projectors, laser precision processing, display, armarium and high speed air water optical wireless communication system with a unique combination of advantages. However, GaN based VCSELs with emission wavelengths in green are challenging because of the low emission efficiency of green emitting InGaN QWs. This is well known as the \"Green Gap\" which is mainly caused by Quantum Confined Stark effect (QCSE) and the high density of defects and dislocations. In this paper, we would like to discuss the origin of \"green gap\" and possible approaches to overcome it, and then review our recent progress in green VCSELs: (1) Lasing from 479.6 nm to 565.7 nm by using QD active area (2) Lasing at 545 nm by using QD in QW active structure; (3) Lasing at 493 nm by utilizing blue emitting InGaN QWs with the combination of cavity effect.",
"author_names": [
"Huan Xu",
"Yang Mei",
"Xu Rongbin",
"Leiying Ying",
"Xuliang Su",
"Jianping Liu",
"Baoping Zhang"
],
"corpus_id": 219517174,
"doc_id": "219517174",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Green VCSELs based on nitride semiconductors",
"venue": "",
"year": 2020
},
{
"abstract": "Abstract. There have been recent research advances in AlGaN based self assembled nanowires (NWs) as building blocks for ultraviolet (UV) optoelectronics grown by plasma assisted molecular beam epitaxy. We review the basic growth kinetics on various foundry compatible metal/silicon based substrates and the epistructure design for UV devices. We highlight the use of diffusion barrier metal thin film on silicon substrate as a solution to enhance device performance. NWs offer the opportunity to mitigate the detrimental quantum confined Stark effect (QCSE) which lowers the recombination rate thereby reducing the device efficiency. On the other hand, the polarization induced doping from the graded composition along NWs can be advantageous for eluding the inefficient doping in AlGaN based UV devices. Sidewall surface states and the associate passivation treatment, as well as the use of ultrafast electron microscopy characterization, are crucial investigations in shedding light on device performance under the influence of surface dangling bonds. For investigating the electrical performance of individual NWs and NWs light emitting diode as a single entity, recent reports based on conductive atomic force microscopy measurements provide fast prototyping in process pass fail evaluation and a means of improving growth for high performance devices. Stress tests of NWs devices, crucial for reliable operation, are also discussed. Beyond applications in LEDs, an AlGaN based NWs solar blind photodetector demonstrated leveraging on the dislocation free active region, reduced QCSE, enhanced light absorption, and tunable composition features. The review opens pathways and offers insights for practical realization of AlGaN based axial NWs devices on scalable and low cost silicon substrates.",
"author_names": [
"Jung-Wook Min",
"Davide Priante",
"Malleswararao Tangi",
"Guangyu Liu",
"Chun Hong Kang",
"Aditya Prabaswara",
"Chao Zhao",
"Latifah Al-Maghrabi",
"Yazeed Alaskar",
"A M Albadri",
"Ahmed Y Alyamani",
"Tien Khee Ng",
"Boon Siew Ooi"
],
"corpus_id": 55562307,
"doc_id": "55562307",
"n_citations": 19,
"n_key_citations": 1,
"score": 0,
"title": "Unleashing the potential of molecular beam epitaxy grown AlGaN based ultraviolet spectrum nanowires devices",
"venue": "",
"year": 2018
}
] |
Plasmonic photocatalysts: harvesting visible light with noble metal nanoparticles | [
{
"abstract": "The efforts to produce photocatalysts operating efficiently under visible light have led to a number of plasmonic photocatalysts, in which noble metal nanoparticles are deposited on the surface of polar semiconductor or insulator particles. In the metal semiconductor composite photocatalysts, the noble metal nanoparticles act as a major component for harvesting visible light due to their surface plasmon resonance while the metal semiconductor interface efficiently separates the photogenerated electrons and holes. In this article, we survey various plasmonic photocatalysts that have been prepared and characterized in recent years.",
"author_names": [
"Peng-peng Wang",
"Baibiao Huang",
"Ying Dai",
"Myung-Hwan Whangbo"
],
"corpus_id": 205812503,
"doc_id": "205812503",
"n_citations": 626,
"n_key_citations": 3,
"score": 1,
"title": "Plasmonic photocatalysts: harvesting visible light with noble metal nanoparticles.",
"venue": "Physical chemistry chemical physics PCCP",
"year": 2012
},
{
"abstract": "Harvesting abundant and renewable sunlight in energy production and environmental remediation is an emerging research topic. Indeed, research on solar driven heterogeneous photocatalysis based on surface plasmon resonance has seen rapid growth and potentially opens a technologically promising avenue that can benefit the sustainable development of global energy and the environment. This review briefly summarizes recent advances in the synthesis and photocatalytic properties of plasmonic composites (e.g. hybrid structures) formed by noble metal (e.g. gold, silver) nanoparticles dispersed on a variety of substrates that are composed of metal oxides, silver halides, graphene oxide, among others. Brief introduction of surface plasmon resonance and the synthesis of noble metal based composites are given, followed by highlighting diverse applications of plasmonic photocatalysts in mineralization of organic pollutants, organic synthesis and water splitting. Insights into surface plasmon resonance mediated photocatalysis not only impact the basic science of heterogeneous photocatalysis, but generate new concepts guiding practical technologies such as wastewater treatment, air purification, selective oxidation reactions, selective reduction reactions, and solar to hydrogen energy conversion in an energy efficient and environmentally benign approach. This review ends with a summary and perspectives.",
"author_names": [
"Xuemei Zhou",
"Gang Liu",
"Jiaguo Yu",
"Wenhong Fan"
],
"corpus_id": 95651475,
"doc_id": "95651475",
"n_citations": 392,
"n_key_citations": 1,
"score": 0,
"title": "Surface plasmon resonance mediated photocatalysis by noble metal based composites under visible light",
"venue": "",
"year": 2012
},
{
"abstract": "Semimetal bismuth with plasmonic properties has triggered increased interests. In this work, a facile strategy was developed to synthesize the Bi/(BiO)2CO3 (Bi BOC) nanocomposites and Bi elemental photocatalysts. The Bi nanoparticles were produced via the insitu reduction of (BiO)2CO3 by NaBH4. The catalysts were utilized for the photocatalytic NO removal under visible light and UV illumination. Significantly, the photocatalytic capability of the Bi BOC was highly enhanced with an unprecedented NO removal of 63.6% The Bi metal demonstrated a direct plasmonic photocatalytic NO removal ratio of 53.6% under UV irradiation. The significantly enhanced photocatalytic capability of Bi BOC can be ascribed to the synergistic effects of the SPR effect, enhanced visible light harvesting and the efficient electron hole separation induced by Bi nanoparticles. The Bi nanoparticles can perform as a non noble metal based plasmonic cocatalyst for advancing photocatalytic ability. The mechanism of photocatalytic NO oxidation was proposed and compared under both visible light and UV illumination. Furthermore, the Bi BOC photocatalysts showed good photochemical stability under repeated tests. This work could not only offer new insights into in situ fine tune reduction strategy for Bi based photocatalysts, but also proves the potentials of utilizing low cost Bi cocatalysts as a substitute for noble metals to improve other photocatalysts.",
"author_names": [
"Yanjuan Sun",
"Zaiwang Zhao",
"Wendong Zhang",
"Chunfeng Gao",
"Yuxin Zhang",
"Fan Dong"
],
"corpus_id": 13459725,
"doc_id": "13459725",
"n_citations": 41,
"n_key_citations": 0,
"score": 0,
"title": "Plasmonic Bi metal as cocatalyst and photocatalyst: The case of Bi/(BiO)2CO3 and Bi particles.",
"venue": "Journal of colloid and interface science",
"year": 2017
},
{
"abstract": "Octahedral anatase particles (OAP) with eight equivalent {101} facets and decahedral anatase particles (DAP) with two additional {001} facets were modified with nanoparticles of noble metals (silver, copper, gold and platinum) by photodeposition, and applied for inactivation of Escherichia coli K12. XRD, DRS, XPS and STEM analyses confirmed the presence of noble metals nanoparticles (NPs) on the surface of faceted titania samples. Both OAP and DAP samples modified with silver and copper exhibited high bactericidal activities under visible light irradiation. It was also found that DAP under UV irradiation showed surprisingly high bactericidal activity, which could be attributed to efficient generation of reactive oxygen species, due to intrinsic properties of DAP, i.e. charge carriers' separation (migration of electrons and holes to {101} and {001} facets, respectively) However, an unexpected decrease in activity after DAP modification with gold and platinum NPs (mainly deposited on {101} facets) suggested that bacteria cells were directly decomposed on DAP surface. SEM images revealed that silver modified samples caused severe damages of cell walls and membranes, due to antibacterial properties of silver (in the dark) and photocatalytic effect under visible and UV irradiation.",
"author_names": [
"Maya Endo",
"Marcin Janczarek",
"Zhishun Wei",
"Kunlei Wang",
"Agata Markowska-Szczupak",
"Bunsho Ohtani",
"Ewa Kowalska"
],
"corpus_id": 53522724,
"doc_id": "53522724",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "Bactericidal Properties of Plasmonic Photocatalysts Composed of Noble Metal Nanoparticles on Faceted Anatase Titania.",
"venue": "Journal of nanoscience and nanotechnology",
"year": 2019
},
{
"abstract": "The utilisation of sunlight as an abundant and renewable resource has motivated the development of sustainable photocatalysts that can collectively harvest visible light. However, the bottleneck in utilising the low energy photons has led to the discovery of plasmonic photocatalysts. The presence of noble metal on the plasmonic photocatalyst enables the harvesting of visible light through the unique characteristic features of the noble metal nanomaterials. Moreover, the formation of interfaces between noble metal particles and semiconductor materials further results in the formation of a Schottky junction. Thereby, the plasmonic characteristics have opened up a new direction in promoting an alternative path that can be of value to the society through sustainable development derived through energy available for all for diverse applications. We have comprehensively prepared this review to specifically focus on fundamental insights into plasmonic photocatalysts, various synthesis routes, together with their strengths and weaknesses, and the interaction of the plasmonic photocatalyst with pollutants as well as the role of active radical generation and identification. The review ends with a pinnacle insight into future perspectives regarding realistic applications of plasmonic photocatalysts.",
"author_names": [
"Kah Hon Leong",
"Azrina Abd Aziz",
"Lan Ching Sim",
"Pichiah Saravanan",
"Min Jang",
"Detlef W Bahnemann"
],
"corpus_id": 3497282,
"doc_id": "3497282",
"n_citations": 38,
"n_key_citations": 1,
"score": 0,
"title": "Mechanistic insights into plasmonic photocatalysts in utilizing visible light",
"venue": "Beilstein journal of nanotechnology",
"year": 2018
},
{
"abstract": "Abstract Pd doped Bi 2 MoO 6 was prepared and investigated for the first time. The prepared samples were characterized by their crystal structures, chemical states, atomic compositions, optical properties and morphologies. The photocatalytic activities of prepared samples under visible light irradiation were determined by degradation of phenol, which is widely found in wastewater from many industrial processes and is difficult to destroy. The sample exhibiting the highest removal efficiency with respect to the degradation of phenol contained 2% Pd. The enhancement effect can be interpreted as the integrated effects of a reduction in the rate of electron hole recombination, surface plasmon resonance, and production of Cl 0 This work sheds light on the potential applications of noble metal nanoparticles in visible light driven photocatalysis.",
"author_names": [
"Xiangchao Meng",
"Zisheng Zhang"
],
"corpus_id": 99718112,
"doc_id": "99718112",
"n_citations": 89,
"n_key_citations": 2,
"score": 0,
"title": "Pd doped Bi 2 MoO 6 plasmonic photocatalysts with enhanced visible light photocatalytic performance",
"venue": "",
"year": 2017
},
{
"abstract": "Abstract Metal organic framework (MOF) is one of the most promising porous materials in photocatalysis. In this study, copper was deposited on as well as encapsulated in a semiconductor like MOF (UiO 66) to fabricate the Cu/Cu@UiO 66 catalyst via an advanced double solvent approach followed by one step reduction. Even with ultralow amount of copper, Cu/Cu@UiO 66 shows significantly enhanced photocatalytic activity as well as stability for partial oxidation of aromatic alcohols under visible light irradiation. The result is attributed to the integration of plasmonic effect (Cu nanoparticles on UiO 66) and Schottky junction (Cu quantum dots encapsulated in UiO 66) which can be considered as a promising noble metal free way for the enhancement of visible light driven photocatalytic activity of MOFs.",
"author_names": [
"Liang Xiao",
"Qi Zhang",
"Peng Chen",
"Lang Chen",
"Feng Ding",
"Jie Tang",
"You-ji Li",
"Chak-tong Au",
"Shuang-Feng Yin"
],
"corpus_id": 104328984,
"doc_id": "104328984",
"n_citations": 39,
"n_key_citations": 0,
"score": 0,
"title": "Copper mediated metal organic framework as efficient photocatalyst for the partial oxidation of aromatic alcohols under visible light irradiation: Synergism of plasmonic effect and schottky junction",
"venue": "Applied Catalysis B: Environmental",
"year": 2019
},
{
"abstract": "Visible light driven water splitting (VLWS) into hydrogen and oxygen is attractive and depends on efficient photocatalysts. Herein, we demonstrate the first exploration of the capability to control the morphology of nanostructured TiO2 in conjunction with the choice of a suitable plasmonic metal (PM) to fabricate novel photocatalysts that are capable of harvesting visible light for more efficient VL fuel conversion. This methodology affords us to successful access to the novel plasmonic Pt/TiO2 HA (large Pt nanoparticles (NPs) supported on TiO2 hierarchical nano architecture (TiO2 HA) photocatalysts that exhibit plasmon absorption in the visible range and consequent outstanding activity and durability for VLWS. Particularly, the Pt/TiO2 HA shows an excellent photocatalytic activity for overall water splitting rather than only for hydrogen evolution (HE) which is superior to those of the conventional plasmonic Au/TiO2 photocatalysts. The synergistic effects of the high Schottky barrier at the Pt TiO2 HA interface, which induces the stronger reduction ability of hot electrons, and intrinsic Pt catalytic activity are responsible for the exceptional photocatalytic performance of Pt/TiO2 HA and simplify the composition of plasmonic photocatalysts.",
"author_names": [
"Lipei Qin",
"Guojing Wang",
"Yiwei Tan"
],
"corpus_id": 53153813,
"doc_id": "53153813",
"n_citations": 27,
"n_key_citations": 0,
"score": 0,
"title": "Plasmonic Pt nanoparticles TiO2 hierarchical nano architecture as a visible light photocatalyst for water splitting",
"venue": "Scientific Reports",
"year": 2018
},
{
"abstract": "Abstract The antimicrobial properties of silver and copper have been exploited since ancient times. Presently, their bactericidal properties are commonly used in the application of noble metals in the form of nanoparticles or nanofilms. Photocatalysis is considered one of the best methods for environmental purification because additional chemical compounds, such as strong oxidants, are not introduced into an environment. The enhancement of antimicrobial properties of heterogeneous photocatalysts (e.g. titania) modified with noble metals under irradiation is probably caused by synergism between dark antimicrobial properties of noble metals and photodisinfection properties of photocatalyst (e.g. reactive oxygen species generated on the surface of irradiated semiconductor) Moreover, it is thought that the additional antimicrobial properties originated from plasmonic heating (under visible light irradiation) may enhance final antimicrobial effect. In this chapter, examples of the application of noble metal based materials for decomposition of both chemical and microbiological pollutants are shortly discussed.",
"author_names": [
"Ewa Kowalska",
"Maya Endo",
"Zhishun Wei",
"Kunlei Wang",
"Marcin Janczarek"
],
"corpus_id": 139596446,
"doc_id": "139596446",
"n_citations": 10,
"n_key_citations": 0,
"score": 0,
"title": "Noble Metal Nanoparticles for Water Purification",
"venue": "",
"year": 2019
},
{
"abstract": "Visible light harvesting by heterogeneous photocatalysts and their applications in organic transformation reactions for the synthesis of target molecules are quite demanding science in the current scenario. In this regard, herein, a novel metal (Au/Pd) functionalized metal organic framework (UiO 66 NH2) was synthesized to carry out the Suzuki Miyaura coupling (SMC) reaction under visible light irradiation at ambient conditions. In order to justify the claim regarding the formation of alloys, crystallinity, morphology, particle size, proper separation of excitons, elemental content and their environment, various sensitive characterization techniques such as XRD, XPS, HRTEM, BET surface area and UV vis analysis were employed. A mechanistic approach by means of experimental investigations revealed that the strong LSPR effect of Au facilitated the transfer of electrons to the Pd surface to make the surface negatively charged and suitable for the activation of aryl halides. The formed electropositive Au nanoparticles were converted to Au0 by accepting the photo induced electrons from pristine UiO 66 NH2 and made available only holes at VB for the activation of phenylboronic acid. Among all the synthesized photocatalysts (1 2) Au/Pd@UiO 66 NH2 showed the highest activity >99% with TOF 426 h 1 in an EtOH/H2O medium towards the SMC reaction, and the highest activity of this catalyst was supported by the electron gas model, LSPR effect (UV vis) and active species separation (PL) analysis. The bimetallic noble nanoparticle anchored UiO 66 NH2 not only expands the synthesis scope of C C coupling by the SMC reaction under ambient conditions but will also inspire the further exploration of the activation of various reactants towards a wide range of organic transformation reactions.",
"author_names": [
"Satyabrata Subudhi",
"Sriram Mansingh",
"Suraj Prakash Tripathy",
"Ashutosh Mohanty",
"Priyabrat Mohapatra",
"Dharitri Rath",
"Kulamani Parida"
],
"corpus_id": 209717441,
"doc_id": "209717441",
"n_citations": 19,
"n_key_citations": 0,
"score": 0,
"title": "The fabrication of Au/Pd plasmonic alloys on UiO 66 NH2: an efficient visible light induced photocatalyst towards the Suzuki Miyaura coupling reaction under ambient conditions",
"venue": "",
"year": 2019
}
] |
"Irina V Grigorieva" | [
{
"abstract": "Research on black phosphorus has been experiencing a renaissance over the last years, after the demonstration that few layer crystals exhibit high carrier mobility and a thickness dependent bandgap. Black phosphorus is also known to be a superconductor under high pressure exceeding 10 GPa. The superconductivity is due to a structural transformation into another allotrope and accompanied by a semiconductor metal transition. No superconductivity could be achieved for black phosphorus in its normal orthorhombic form, despite several reported attempts. Here we describe its intercalation by several alkali metals (Li, K, Rb and Cs) and alkali earth Ca. All the intercalated compounds are found to be superconducting, exhibiting the same (within experimental accuracy) critical temperature of 3.8+ 0.1 K and practically identical characteristics in the superconducting state. Such universal superconductivity, independent of the chemical composition, is highly unusual. We attribute it to intrinsic superconductivity of heavily doped individual phosphorene layers, while the intercalated layers of metal atoms play mostly a role of charge reservoirs.",
"author_names": [
"R Zhang",
"John Waters",
"Andre K Geim",
"Irina V Grigorieva"
],
"corpus_id": 19583383,
"doc_id": "19583383",
"n_citations": 60,
"n_key_citations": 0,
"score": 0,
"title": "Intercalant independent transition temperature in superconducting black phosphorus",
"venue": "Nature communications",
"year": 2017
},
{
"abstract": "Superconducting layered transition metal dichalcogenides (TMDs) stand out among other superconductors due to the tunable nature of the superconducting transition, coexistence with other collective electronic excitations (charge density waves) and strong intrinsic spin orbit coupling. Molybdenum disulfide (MoS2) is the most studied representative of this family of materials, especially since the recent demonstration of the possibility to tune its critical temperature, Tc, by electric field doping. However, just one of its polymorphs, band insulator 2H MoS2, has so far been explored for its potential to host superconductivity. We have investigated the possibility to induce superconductivity in metallic polytypes, 1T and 1T' MoS2, by potassium (K) intercalation. We demonstrate that at doping levels significantly higher than that required to induce superconductivity in 2H MoS2, both 1T and 1T' phases become superconducting with Tc 2.8 and 4.6 K, respectively. Unusually, K intercalation in this case is responsible both for the structural and superconducting phase transitions. By adding new members to the family of superconducting TMDs, our findings open the way to further manipulate and enhance the electronic properties of these technologically important materials.",
"author_names": [
"Renyan Zhang",
"I -Ling Tsai",
"James Chapman",
"Ekaterina Khestanova",
"John Waters",
"Irina V Grigorieva"
],
"corpus_id": 21094286,
"doc_id": "21094286",
"n_citations": 82,
"n_key_citations": 1,
"score": 0,
"title": "Superconductivity in Potassium Doped Metallic Polymorphs of MoS2.",
"venue": "Nano letters",
"year": 2016
},
{
"abstract": "Using computer simulation, we have studied the random sequential adsorption of stiff linear segments (needles) onto a square lattice. Each such particle occupies $k$ adjacent lattice sites, thence, it is frequently called a $k$ mer. During deposition, the two mutually perpendicular orientations of the particles are equiprobable, hence, a macroscopically isotropic monolayer is formed. However, this monolayer is locally anisotropic, since the deposited particles tend to form so called `stacks' i.e. domains of particles with the same orientation. Using the `excluded area' concept, we have classified lattice sites into several types and examined how the fraction of each type of lattice site varies as the number of deposited particles increases. The behaviors of these quantities have allowed us to identify the following stages of stack formation (i) the emergence of stack seeds; (ii) the filling of stacks; (iii) densification of the stacks.",
"author_names": [
"Mikhail Ulyanov",
"Yuri Yu Tarasevich",
"Andrei V Eserkepov",
"Irina V Grigorieva"
],
"corpus_id": 219177265,
"doc_id": "219177265",
"n_citations": 0,
"n_key_citations": 0,
"score": 1,
"title": "Stack formation during random sequential adsorption of needles onto a square lattice",
"venue": "",
"year": 2020
},
{
"abstract": "",
"author_names": [
"Irina V Grigorieva",
"Aynakul B Tumanova"
],
"corpus_id": 182147719,
"doc_id": "182147719",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "From the conceptual analysis experience: free associative experiment",
"venue": "",
"year": 2019
},
{
"abstract": "Despite graphene's long list of exceptional electronic properties and many theoretical predictions regarding the possibility of superconductivity in graphene, its direct and unambiguous experimental observation has not been achieved. We searched for superconductivity in weakly interacting, metal decorated graphene crystals assembled into so called graphene laminates, consisting of well separated and electronically decoupled graphene crystallites. We report robust superconductivity in all Ca doped graphene laminates. They become superconducting at temperatures (Tc) between 4 and 6 K, with Tc's strongly dependent on the confinement of the Ca layer and the induced charge carrier concentration in graphene. We find that Ca is the only dopant that induces superconductivity in graphene laminates above 1.8 K among several dopants used in our experiments, such as potassium, caesium and lithium. By revealing the tunability of the superconducting response through doping and confinement of the metal layer, our work shows that achieving superconductivity in free standing, metal decorated monolayer graphene is conditional on an optimum confinement of the metal layer and sufficient doping, thereby bringing its experimental realization within grasp.",
"author_names": [
"James Chapman",
"Y Su",
"Christopher A Howard",
"Dmytro Kundys",
"Alexander N Grigorenko",
"Francisco Guinea",
"Andre K Geim",
"Irina V Grigorieva",
"Rahul R Nair"
],
"corpus_id": 620826,
"doc_id": "620826",
"n_citations": 82,
"n_key_citations": 0,
"score": 0,
"title": "Superconductivity in Ca doped graphene laminates",
"venue": "Scientific reports",
"year": 2016
},
{
"abstract": "Despite being only one atom thick, defect free graphene is considered to be completely impermeable to all gases and liquids 1 10 This conclusion is based on theory 3 8 and supported by experiments 1 9 10 that could not detect gas permeation through micrometre size membranes within a detection limit of 10 5 to 10 6 atoms per second. Here, using small monocrystalline containers tightly sealed with graphene, we show that defect free graphene is impermeable with an accuracy of eight to nine orders of magnitude higher than in the previous experiments. We are capable of discerning (but did not observe) permeation of just a few helium atoms per hour, and this detection limit is also valid for all other gases tested (neon, nitrogen, oxygen, argon, krypton and xenon) except for hydrogen. Hydrogen shows noticeable permeation, even though its molecule is larger than helium and should experience a higher energy barrier. This puzzling observation is attributed to a two stage process that involves dissociation of molecular hydrogen at catalytically active graphene ripples, followed by adsorbed atoms flipping to the other side of the graphene sheet with a relatively low activation energy of about 1.0 electronvolt, a value close to that previously reported for proton transport 11 12 Our work provides a key reference for the impermeability of two dimensional materials and is important from a fundamental perspective and for their potential applications. Graphene is shown to be impermeable to helium and several other gases, except for hydrogen, which is attributed to the strong catalytic activity of ripples in the graphene sheet.",
"author_names": [
"P Z Sun",
"Q Yang",
"Wenjun Kuang",
"Yury V Stebunov",
"Wei Xiong",
"J Yu",
"Rahul R Nair",
"Mikhail I Katsnelson",
"Shengjun Yuan",
"Irina V Grigorieva",
"Marcelo Lozada-Hidalgo",
"F C Wang",
"Andre K Geim"
],
"corpus_id": 211146417,
"doc_id": "211146417",
"n_citations": 62,
"n_key_citations": 0,
"score": 0,
"title": "Limits on gas impermeability of graphene",
"venue": "Nature",
"year": 2020
},
{
"abstract": "",
"author_names": [
"Olga Vygovskaya-Kazarina",
"Nataliya M Shlenskaya",
"Elena A Golubovskaya",
"Natalia Mekeko",
"I G Grigorieva"
],
"corpus_id": 69986685,
"doc_id": "69986685",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "EDUCATIONAL PRINCIPLES IN LANGUAGE LEARNING: TRAINING OF MEDIA TEXT SLANG TRANSLATION",
"venue": "",
"year": 2018
},
{
"abstract": "Raman spectroscopy is an ideal tool for the characterization of strained graphene. Biaxial strain, in particular, allows for more reliable calculation of the Gruneisen parameters than uniaxial strain. However, the application of biaxial strain is rather difficult to achieve experimentally, so all previous studies reported on graphene subjected to relatively small biaxial strains (0.1% 1% in contrast to uniaxial strain above 10% Here, we report a simple fabrication technique to produce pressurized and stable graphene membranes that can support differential pressures up to 14 bar, corresponding to a reversible strain up to ~2% We find that the Gruneisen parameters remain constant even for the largest strains achieved, in agreement with the theoretical predictions. However, for strains above 1% a distinctive broadening of both the G and 2D peaks was observed for biaxial strain. We attribute this to the nanoscale variations of strain in the membrane within an area comparable with the laser spot size.",
"author_names": [
"Yuyoung Shin",
"Marcelo Lozada-Hidalgo",
"J L Sambricio",
"Irina V Grigorieva",
"Andre K Geim",
"Cinzia Casiraghi"
],
"corpus_id": 100355381,
"doc_id": "100355381",
"n_citations": 34,
"n_key_citations": 2,
"score": 0,
"title": "Raman spectroscopy of highly pressurized graphene membranes",
"venue": "",
"year": 2016
},
{
"abstract": "We report on an extensive investigation to figure out the origin of room temperature ferromagnetism that is commonly observed by SQUID magnetometry in highly oriented pyrolytic graphite (HOPG) Electron backscattering and X ray microanalysis revealed the presence of micron size magnetic clusters (predominantly Fe) that are rare and would be difficult to detect without careful search in a scanning electron microscope in the backscattering mode. The clusters pin to crystal boundaries and their quantities match the amplitude of typical ferromagnetic signals. No ferromagnetic response is detected in samples where we could not find such magnetic inclusions. Our experiments show that the frequently reported ferromagnetism in pristine HOPG is most likely to originate from contamination with Fe rich inclusions introduced presumably during crystal growth.",
"author_names": [
"Margherita Sepioni",
"Rahul R Nair",
"I -Ling Tsai",
"Andre K Geim",
"Irina V Grigorieva"
],
"corpus_id": 204936414,
"doc_id": "204936414",
"n_citations": 48,
"n_key_citations": 1,
"score": 0,
"title": "Revealing common artifacts due to ferromagnetic inclusions in highly oriented pyrolytic graphite",
"venue": "",
"year": 2012
},
{
"abstract": "Trapped substances between a 2D crystal, such as graphene, and an atomically flat substrate, for example, hexagonal boron nitride, give rise to the formation of bubbles. We show that the size, shape and internal pressure inside these bubbles are determined by the competition between van der Waals attraction of a 2D crystal to the substrate and the elastic energy needed to deform the atomically thin layer. This presents opportunities to use bubbles to study the elasticity of 2D materials as well as the conditions of confinement, yet none of these have been explored so far, either theoretically or experimentally. We have created a variety of bubbles formed by monolayers of graphene, hBN and MoS2 mechanically exfoliated onto hBN, graphite and MoS2 substrates. Their shapes, analyzed using atomic force microscopy, are found to exhibit universal scaling with well defined aspect ratios, in agreement with theoretical analysis based on general properties of membranes. We also measured the pressure induced by the confinement, which increased with decreasing bubble's size and reached tens on MPa inside submicron bubbles. This agrees with our theory estimates and suggests that for bubbles with radii 10 nm hydrostatic pressures can reach close to 1 GPa, which may modify the properties of a trapped material.",
"author_names": [
"Ekaterina Khestanova",
"Francisco Guinea",
"Laura Fumagalli",
"Andre K Geim",
"Irina V Grigorieva"
],
"corpus_id": 55939789,
"doc_id": "55939789",
"n_citations": 94,
"n_key_citations": 0,
"score": 0,
"title": "Graphene bubbles on a substrate Universal shape and van der Waals pressure",
"venue": "",
"year": 2016
}
] |
Robust design of selectively compliant flexure-based precision mechanisms | [
{
"abstract": "Acknowledgments I wish to thank a number of people who have helped me in my professional and personal development during my graduate studies at The University of Texas at Austin. Firstly, I would like to express my sincere gratitude to Prof. Raul G. Lon goria, who has been more than a mentor to me. His guidance, motivation, and support have been critical in all my accomplishments in graduate school. I would like to thank Prof. S. V. Sreenivasan, who helped me to overcome my weaknesses, by instilling discipline and confidence in my work. His professionalism and down to earth demeanor will always be inspirational to me. valuable suggestions in improving the dissertation. I would like to especially thank Dr. Choi and engineers at Molecular Imprints, namely, Pawan Kumar, and Mario Meissl, for their help with the experimental work included in the dissertation. Engineering, and the Office of Graduate Studies for financial support throughout my graduate education. v Finally, a special note of appreciation to my family members. To my beloved wife, Rashmi, whose many sacrifices, and unflinching support carried us through the travails and triumphs of higher education, I couldnt be more thankful. To my parents, for their patience, encouragement, and faith in me, Nano scale positioning and metrology are at the cutting edge of motion control technology, driven by ever increasing number of applications, including semiconductor fabrication, data storage, nano fabrication, biotechnology among others. In this 'very small range (few um) and very high precision (few nm) domain' flexure based mechanisms are the preferred means for the motion guiding systems, because of several exceptional properties like selective compliance, monolithic design, absence of friction, hysteresis, and wear. However, despite their numerous advantages, their motion characteristics are extremely sensitive to thermal variations, material property variations, machining tolerances among others. The geometric errors induced by machining process variations interact with the mechanism geometry, and lead to parasitic motion in directions other than the mechanism degrees of freedom. These errors cannot be completely eliminated by calibration, as they are coupled with the desired mechanism motion. vii This thesis focuses on the problem of parasitic motion in flexure based precision compliant mechanisms in the presence of geometric errors induced by machining tolerances. A spatial kinematics approach based on screw systems is used to model the compliance of the flexure mechanisms. The geometric errors induced by machining tolerances are systematically included in the modeling. The model not only determines the complete spatial",
"author_names": [
"Chinmaya B Patil"
],
"corpus_id": 107812486,
"doc_id": "107812486",
"n_citations": 6,
"n_key_citations": 0,
"score": 1,
"title": "Robust design of selectively compliant flexure based precision mechanisms",
"venue": "",
"year": 2008
},
{
"abstract": "Preface INTRODUCTION COMPLIANCE BASED DESIGN OF FLEXURE HINGES Introduction Generic Mathematical Formulation Single Axis Flexure Hinges for Two Dimensional Applications Multiple Axis Flexure Hinges for Three Dimensional Applications Two Axis Flexure Hinges for Three Dimensional Applications Conclusions STATICS OF FLEXURE BASED COMPLIANT MECHANISMS Introduction Planar Compliant Mechanisms Spatial Compliant Mechanisms DYNAMICS OF FLEXURE BASED COMPLIANT MECHANISMS Introduction Elastic Potential Energy for Individual Flexure Hinges Kinetic Energy for Individual Flexure Hinges Free and Forced Response of Flexure Based Compliant Mechanisms Damping Effects FINITE ELEMENT FORMULATION FOR FLEXURE HINGES AND FLEXURE BASED COMPLIANT MECHANISMS Introduction Generic Formulation Elemental Matrices for Flexure Hinges Elemental Matrices for Rigid Links Application Example Appendix TOPICS BEYOND THE MINIMAL MODELING APPROACH TO FLEXURE HINGES Large Deformations Buckling Torsion of Noncircular Cross Section Flexure Hinges Composite Flexure Hinges Thermal Effects Shape Optimization Means of Actuation Fabrication APPLICATIONS OF FLEXURE BASED COMPLIANT MECHANISMS Macroscale Applications Microscale (MEMS) Applications",
"author_names": [
"Nicolae Lobontiu"
],
"corpus_id": 106467897,
"doc_id": "106467897",
"n_citations": 622,
"n_key_citations": 43,
"score": 0,
"title": "Compliant Mechanisms: Design of Flexure Hinges",
"venue": "",
"year": 2002
},
{
"abstract": "Flexure joints are widely used to approximate the function of traditional mechanical joints, while offering the benefits of high precision, long life, and ease of manufacture. This paper investigates and catalogs the drawbacks of typical flexure connectors and presents several new designs for highlyeffective, kinematically behaved compliant joints. A revolute and a translational compliant joint are proposed (Figure 1) both of which offer great improvements over existing flexures in the qualities of (1) large range of motion, (2) minimal axis drift, (3) increased off axis stiffness, and (4) reduced stressconcentrations. Analytic stiffness equations are developed for each joint and parametric computer models are used to verify their superior stiffness properties. A catalog of design charts based on the parametric models is also presented, allowing for rapid sizing of the joints for custom performance. Finally, two multi degree of freedom joints are proposed as modifications to the revolute joint. These include a compliant universal joint and a compliant spherical joint, both designed to provide high degrees of compliance in the desired direction of motion and high stiffness in other directions.",
"author_names": [
"Brian Trease",
"Yong Mo Moon",
"Sridhar Kota"
],
"corpus_id": 110735691,
"doc_id": "110735691",
"n_citations": 287,
"n_key_citations": 14,
"score": 0,
"title": "DESIGN OF LARGE DISPLACEMENT COMPLIANT JOINTS",
"venue": "",
"year": 2005
},
{
"abstract": "In this paper, a quantitative comparison is made between straight beam and curved beam flexures for application on selectively compliant mechanisms. Following a general procedure previously described in the literature, the closed form compliance equations for both flexural hinges are firstly derived. Then, the two morphologies are compared in terms of maximum achievable rotation and selective compliance (i.e. capability of providing low stiffness along a single desired direction) In particular, the performance of each design solution is quantified by means of purposely defined quality indexes, analytically computed on the basis of the hinges compliance matrix. Finally, the potentials of these types of flexures for the optimal design of compliant robotic fingers are critically discussed.",
"author_names": [
"Giovanni Berselli",
"Farid Parvari Rad",
"Rocco Vertechy",
"Vincenzo Parenti-Castelli"
],
"corpus_id": 18882274,
"doc_id": "18882274",
"n_citations": 11,
"n_key_citations": 1,
"score": 0,
"title": "Comparative evaluation of straight and curved beam flexures for selectively compliant mechanisms",
"venue": "2013 IEEE/ASME International Conference on Advanced Intelligent Mechatronics",
"year": 2013
},
{
"abstract": "This paper introduces the iRobot Harvard Yale (iHY) Hand, an underactuated hand driven by five actuators that is capable of performing a wide range of grasping and in hand repositioning tasks. This hand was designed to address the need for a durable, inexpensive, moderately dexterous hand suitable for use on mobile robots. The primary focus of this paper will be on the novel simplified design of the iHY Hand, which was developed by choosing a set of target tasks around which the hand was optimized. Particular emphasis is placed on the development of underactuated fingers that are capable of both firm power grasps and low stiffness fingertip grasps using only the compliant mechanics of the fingers. Experimental results demonstrate successful grasping of a wide range of target objects, the stability of fingertip grasping, and the ability to adjust the force exerted on grasped objects using high impedance actuators and underactuated fingers.",
"author_names": [
"Lael Odhner",
"Leif P Jentoft",
"Mark R Claffee",
"Nick Corson",
"Yaroslav Tenzer",
"Raymond R Ma",
"Martin Buehler",
"Robert C Kohout",
"Robert D Howe",
"Aaron M Dollar"
],
"corpus_id": 1022095,
"doc_id": "1022095",
"n_citations": 374,
"n_key_citations": 21,
"score": 0,
"title": "A compliant, underactuated hand for robust manipulation",
"venue": "Int. J. Robotics Res.",
"year": 2014
},
{
"abstract": "This paper presents the design and control of a novel gripper device with a passive type of compliant constant force mechanism. The function of constant force output is achieved by using the combination of a positive stiffness and a negative stiffness mechanism. The negative stiffness is generated by a bistable buckled fixed guided beam. Conventionally, when gripping a target object using a high stiffness gripper, both the displacement control and force control are required to prevent the damage of the object. The uniqueness of the developed constant force gripper is that it can eliminate the dependence on force control while keeping the force constant via its mechanical structure. The gripper performance is evaluated by the established analytical model and nonlinear finite element analysis, and validated through experimental study on a fabricated prototype. To achieve a precise position output of the gripper jaw, a discrete time variable structure control strategy based on a nonswitching type of reaching law is realized. The effectiveness of the gripper system is verified by conducting experimental studies on grasp hold release operations of a micro copper wire.",
"author_names": [
"Yilin Liu",
"Yulong Zhang",
"Qingsong Xu"
],
"corpus_id": 11060057,
"doc_id": "11060057",
"n_citations": 55,
"n_key_citations": 0,
"score": 0,
"title": "Design and Control of a Novel Compliant Constant Force Gripper Based on Buckled Fixed Guided Beams",
"venue": "IEEE/ASME Transactions on Mechatronics",
"year": 2017
},
{
"abstract": "This paper presents a line element based approach to the topology synthesis of electrothermal compliant (ETC) mechanisms. A line element is a one dimensional model of the electrical, thermal, and elastic behavior of a beam like continuum. In contrast to topology synthesis of ETC mechanisms by a continuum element based approach, the line element based approach offers significant conceptual and practical advantages. The line element allows for straightforward modeling of surface heat transfer in the topology optimization framework. It also obviates the need to interpolate electrical and thermophysical properties in the topology synthesis procedure. Moreover, this approach results in clean geometries that are easy to fabricate directly in their optimized form. Solutions obtained from this procedure are compared with results from continuum based optimal synthesis procedures as well as intuitive designs reported in the literature. A number of design examples are used to demonstrate the ability of the procedure to generate nonintuitive topologies. The synthesis procedure is also used to study the influence of the direction of output and the electrical and thermal resistance of the workpiece on the resulting optimal topologies.",
"author_names": [
"Nilesh D Mankame",
"G K Ananthasuresh"
],
"corpus_id": 55120608,
"doc_id": "55120608",
"n_citations": 25,
"n_key_citations": 1,
"score": 0,
"title": "Topology synthesis of electrothermal compliant mechanisms using line elements",
"venue": "",
"year": 2004
},
{
"abstract": "The consideration of compliant mechanisms as Microelectromechanical Systems (MEMS) is the focus of this research endeavor. MEMS are micron to millimeter devices that combine electrical, mechanical, and information processing capabilities on the same device. These MEMS need some mechanical motion or parts that move relative to each other. This relative motion, using multiple parts, is not desired because of the assembly requirement and the friction introduced. Compliant devices limits or eliminates friction and the need for multi component assembly. Compliant devices improve designs by creating single piece mechanisms. The purpose of this research is to validate surface micromachining as a viable fabrication process for compliant MEMS designs. Specifically, this research has sought to fabricate a micro compliant gripper and a micro compliant clamp to illustrate the process. While other researchers have created compliant MEMS, most have used comb drive actuation methods and bulk micromachining processes. This research focuses on fully compliant devices that use device flexibility for motion and actuation. Validation of these compliant MEMS is achieved by structural optimization of device design and functional performance testing. This research contributes to the ongoing research in MEMS by evaluating the potential of using surface micromachining as a process for fabricating compliant micro mechanisms.",
"author_names": [
"Joe A Bradley"
],
"corpus_id": 36978275,
"doc_id": "36978275",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Design of Surface Micromachined Compliant MEMS",
"venue": "",
"year": 2002
},
{
"abstract": "Robotic origami design allows creating meso scale robotic systems and mechanisms not limited by degrees of freedom, miniaturization and assembly downsides of conventional transmission mechanisms. However, unlike the traditional rigid approaches, robotic origami application has been limited by the complex deformation and kinematics of the compliant joints and actuation based on active materials or conventional electric motors. To generalize their application at meso scale requires a combination of the predictability of traditional rigid kinematics and the manufacturing flexibility of robotic origami. Here we present a study of conventional transmission mechanisms, including a slider crank and cam follower, made in quasi 2D form by selective machining and stacking of multiple layers of composite material with minimal assembly. Owing to a compliant design powered by low profile piezoelectric motors, our 5.3 mm thick and lightweight mechanisms transmit rotational motion to translational movements in and out of plane. We develop analytic models that we validate in terms of force and motion output on our prototypes.",
"author_names": [
"Frederic Giraud",
"Zhenishbek Zhakypov",
"Jamie Kyujin Paik"
],
"corpus_id": 210970862,
"doc_id": "210970862",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Design of Low Profile Compliant Transmission Mechanisms",
"venue": "2019 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)",
"year": 2019
},
{
"abstract": "Abstract This paper presents the design, development, and control of a large range beam flexure based nano servo system for the micro stereolithography (MSL) process. As a key enabler of high accuracy in this process, a compact desktop size beam flexure based nanopositioner was designed with millimeter range and nanometric motion quality. This beam flexure based motion system is highly suitable for harsh operation conditions, as no assembly or maintenance is required during the operation. From a mechanism design viewpoint, a mirror symmetric arrangement and appropriate redundant constraints are crucial to reduce undesired parasitic motion. Detailed finite element analysis (FEA) was conducted and showed satisfactory mechanical features. With the identified dynamic models of the nanopositioner, real time control strategies were designed and implemented into the monolithically fabricated prototype system, demonstrating the enhanced tracking capability of the MSL process. The servo system has both a millimeter operating range and a root mean square (RMS) tracking error of about 80 nm for a circular trajectory.",
"author_names": [
"Zhen Zhang",
"Peng Yan",
"Guangbo Hao"
],
"corpus_id": 73570634,
"doc_id": "73570634",
"n_citations": 13,
"n_key_citations": 0,
"score": 0,
"title": "A Large Range Flexure Based Servo System Supporting Precision Additive Manufacturing",
"venue": "",
"year": 2017
}
] |
TRANSPARENT CONDUCTING OXIDE FILMS FOR VARIOUS APPLICATIONS: A REVIEW | [
{
"abstract": "Abstract This review encompasses properties and applications of polycrystalline or amorphous, Transparent Conducting Oxides (TCO) semiconductors. Coexistence of electrical conductivity and optical transparency in TCO depends on the nature, number and atomic arrangements of metal cations in oxides, on the resident morphology and presence of intrinsic or introduced defects. Therefore, TCO semiconductors that are impurity doped as well as the ternary compounds and multi component oxides consisting of combinations are discussed. Expanding use of TCO is endangered by scarcity, cost of In, fragility of glass, limited transparency to visible light, instability above >200 degC, non flexible for application of flexible solar cell; thus driving search for alternatives such as graphene or CNT, that are more stable under acidic, alkaline, oxidizing, reducing and elevated temperature. There are reasons to conclude that there is need to develop large area deposition techniques to produce TCO films with high deposition rate. TCOs are mostly n type semiconductors, but p type are also being researched",
"author_names": [
"Rakesh A Afre",
"Nallin Sharma",
"Maheshwar Sharon",
"Madhuri Sharon"
],
"corpus_id": 109934040,
"doc_id": "109934040",
"n_citations": 82,
"n_key_citations": 1,
"score": 1,
"title": "Transparent Conducting Oxide Films for Various Applications: A Review",
"venue": "",
"year": 2018
},
{
"abstract": "Due to its exceptional electrical, optical, chemical and magnetic properties, tin oxide (SnO and SnO2) which is a functional material, has gained enormous attention for use in a variety of applications. Films of SnOX have a direct band gap between the ranges of 2.2 and 3.6 eV, with these films finding usefulness in various functions such as solar cells, transparent conducting oxides for gas sensors, lithium ion batteries and microelectronics, and use in the optoelectronics industries. In order to satisfy the needs of a broad range of these applications, thin films with an extensive properties span defined by film composition, thickness, structural properties and morphology are required. This article explains the theory and research status of the various manufacturing processes of tin oxide. The purpose is to analyze the effects of the thin films through distinct forms of deposition. The general finding summarized in this research on SnOX showed that various researchers studied specific characteristics of tin oxide properties restricted by experimental conditions.",
"author_names": [
"Emeka Charles Nwanna",
"Patrick Ehi Imoisili",
"Tien-Chien Jen"
],
"corpus_id": 228854873,
"doc_id": "228854873",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Fabrication and synthesis of SnOX thin films: a review",
"venue": "",
"year": 2020
},
{
"abstract": "The use of carbon nanotubes (CNTs) as transparent conducting films is one of the most promising aspects of CNT based applications due to their high electrical conductivity, transparency, and flexibility. However, despite many efforts in this field, the conductivity of carbon nanotube network films at high transmittance is still not sufficient to replace the present electrodes, indium tin oxide (ITO) due to the contact resistances and semi conducting nanotubes of the nanotube network films. Many studies have attempted to overcome such problems by the chemical doping and hybridization of conducting guest components by various methods, including acid treatment, deposition of metal nanoparticles, and the creation of a composite of conducting polymers. This review focuses on recent advances in surface modified carbon nanotube networks for transparent conducting film applications. Fabrication methods will be described, and the stability of carbon nanotube network films prepared by various methods will be demonstrated.",
"author_names": [
"Seung Bo Yang",
"Byung-Seon Kong",
"D Jung",
"Youn-Kyoung Baek",
"Chang-Soo Han",
"Sang-keun Oh",
"Hee-Tae Jung"
],
"corpus_id": 24954824,
"doc_id": "24954824",
"n_citations": 83,
"n_key_citations": 3,
"score": 1,
"title": "Recent advances in hybrids of carbon nanotube network films and nanomaterials for their potential applications as transparent conducting films.",
"venue": "Nanoscale",
"year": 2011
},
{
"abstract": "Thin films of transparent conducting oxides (TCO) are technologically important for applications as a visible light transparent electrode in a wide variety of optoelectronic devices. In the last few years, researchers started to explore novel size and shape dependent properties of TCO, where the crystallite size is ~10 nm. So far, the localized surface plasmon resonance (LSPR) properties of TCO nanocrystals (NCs) have been found to be the most interesting. TCOs like Sn doped In2O3, Al doped ZnO and In doped CdO NCs, exhibit LSPR band in near to mid infrared region. LSPR from a TCO NC exhibits many intrinsic differences with that of a metal NC. Carrier density in a TCO NC can easily be tuned by controlling the dopant concentration, which allows the LSPR band to be tuned over a range of ~2000 nm ~0.62 eV) in the near to mid infrared region. This review discusses recent advances in the understanding of plasmonic properties of various TCO NCs and highlights the potential applications of such unique plasmonic properties.",
"author_names": [
"Bharat Tandon",
"Aswathi Ashok",
"Angshuman Nag"
],
"corpus_id": 118227837,
"doc_id": "118227837",
"n_citations": 10,
"n_key_citations": 0,
"score": 0,
"title": "Colloidal transparent conducting oxide nanocrystals: A new infrared plasmonic material",
"venue": "",
"year": 2015
},
{
"abstract": "Recent research papers for zinc oxide (ZnO) thin films prepared by dip coating method are reviewed. The aim is on the factors affecting the properties of ZnO thin films prepared by dip coating method and the preparation of ZnO solution precursor using sol gel process. Several of journals have been discovered to find out the related study on this topic. It was found that solution chemical equilibrium, substrate and thermal processing are the factors that contribute to the various properties of ZnO thin films. This review hopefully can help in improving the properties of ZnO thin film for possible applications to photoconductor, integrated sensor, transparent conducting oxide electrodes, optoelectronic devices and so on.",
"author_names": [
"M F Malek",
"Mohamad Hafiz Mamat",
"Mohamed Zahidi Musa",
"Mohd Zainizan Sahdan",
"Mohamad Rusop Mahmood"
],
"corpus_id": 137588676,
"doc_id": "137588676",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Factors Affecting the Properties of Zinc Oxide Thin Films Prepared by Dip Coating Method: A Review",
"venue": "",
"year": 2013
},
{
"abstract": "Abstract Graphene has been recognised for its various excellent properties and its potential to be applied in various applications such as transparent conducting films (TCF) optoelectronic devices and energy storage. Graphene has been successfully synthesised by various methods including chemical vapour deposition (CVD) exfoliation and solution processed. As synthesised graphene has been used in various applications and its potentials have been realised. However, graphene performance has been compromised due to various factors. In this review, we present the methods to improve graphene performance by doping, enhancement of transfer methods and hybrid films of graphene with other materials. In addition, graphene as TCF for photovoltaic applications has also been described. We also include a discussion on various Figure of Merit (FOM) determinations, to evaluate the performance of graphene as transparent conducting films.",
"author_names": [
"Nurul Nazli Rosli",
"Mohd Adib Ibrahim",
"Norasikin Ahmad Ludin",
"Mohd Asri Mat Teridi",
"Kamaruzzaman Sopian"
],
"corpus_id": 117727691,
"doc_id": "117727691",
"n_citations": 41,
"n_key_citations": 0,
"score": 0,
"title": "A review of graphene based transparent conducting films for use in solar photovoltaic applications",
"venue": "",
"year": 2019
},
{
"abstract": "This article reviews and summarizes work recently performed in this laboratory on the synthesis of advanced transparent conducting oxide nanopowders by the use of plasma. The nanopowders thus synthesized include indium tin oxide (ITO) zinc oxide (ZnO) and tin doped zinc oxide (TZO) aluminum doped zinc oxide (AZO) and indium doped zinc oxide (IZO) These oxides have excellent transparent conducting properties, among other useful characteristics. ZnO and TZO also has photocatalytic properties. The synthesis of these materials started with the selection of the suitable precursors, which were injected into a non transferred thermal plasma and vaporized followed by vapor phase reactions to form nanosized oxide particles. The products were analyzed by the use of various advanced instrumental analysis techniques, and their useful properties were tested by different appropriate methods. The thermal plasma process showed a considerable potential as an efficient technique for synthesizing oxide nanopowders. This process is also suitable for large scale production of nano sized powders owing to the availability of high temperatures for volatilizing reactants rapidly, followed by vapor phase reactions and rapid quenching to yield nano sized powder.",
"author_names": [
"Hong Yong Sohn",
"Arun Murali"
],
"corpus_id": 232259174,
"doc_id": "232259174",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Plasma Synthesis of Advanced Metal Oxide Nanoparticles and Their Applications as Transparent Conducting Oxide Thin Films",
"venue": "Molecules",
"year": 2021
},
{
"abstract": "Abstract Electrochromic devices (ECD) show reversible color change under applied electric field and are predicted to become indispensable in many applications such as low power displays, smart windows to develop energy saving buildings as well as light adapting mirrors in high end cars and aircrafts. Despite the assiduous research work, ECD faces several challenges for practical usage including delamination, durability, lifetime and their integration into multifunctional devices. To improve the performance, different techniques have already been used to deposit single layered thin film, or a stack of promising EC layers on several substrates including transparent conductive oxides (TCO) coated glass and different conducting polymers. These layers can be flat enough or have a definite shape or structure to satisfy the needs of the designed device. Based on their low resistivity and high transparency, fluorine and indium doped tin oxides (FTO, ITO) are mostly used as TCOs whereas polyaniline, polypyrrole and ethylenedioxythiophene are the trending future polymers. In this review, the critical parameters of magnetron sputtering are delineated for the deposited tungsten oxide (WO3) films focused on ITO and FTO layered glass. The main focus of interest is to highlight the recent progress and future trends in this technique, structure introduced with sputtered electrochromic film and their carefully review along with effect of altering these parameters on physical, optical, electrochemical, durability and thus overall performance of the ECD. Finally, it will be intended to underline the future perspectives in realizing smart EC devices with various factual characteristics.",
"author_names": [
"Ahmar Mehmood",
"Xueyuan Long",
"Azhar Ali Haidry",
"Xiaogang Zhang"
],
"corpus_id": 224900235,
"doc_id": "224900235",
"n_citations": 13,
"n_key_citations": 0,
"score": 0,
"title": "Trends in sputter deposited tungsten oxide structures for electrochromic applications: A review",
"venue": "",
"year": 2020
},
{
"abstract": "Abstract Here we present an in depth atomic force microscopy study of aluminum doped zinc oxide (AZO) thin films utilizing various modes (topology, phase and error signal) together with image processing techniques including skew, kurtosis, entropy, autocorrelation and fractal analysis. Fractal dimension has been calculated via cube counting, triangulation, power spectrum and partitioning methods. A correlation has been found between the micromorphological properties and the functional properties of the AZO transparent conducting oxide when annealed at different temperatures. Structural, electrical, morphological and optical properties of AZO thin films were investigated by XRD, 4 Point probe, AFM and UV VIS spectroscopy. The results indicate that the AZO thin film properties are affected by substrate temperature. An optimum figure of merit of 1.518 x 10 3 O 1 is obtained for a substrate temperature of 150 degC It is expected that this work can provide a novel approach towards optimization of transparent conducting oxides, in particular with regards to plasmonics.",
"author_names": [
"Payam Rajabi Kalvani",
"Alireza Jahangiri",
"Samaneh Shapouri",
"Amir Hossein Sari",
"Yousef Seyed Jalili"
],
"corpus_id": 198468676,
"doc_id": "198468676",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "Multimode AFM analysis of aluminum doped zinc oxide thin films sputtered under various substrate temperatures for optoelectronic applications",
"venue": "Superlattices and Microstructures",
"year": 2019
},
{
"abstract": "Abstract The oxides and their interplay with metals are of central importance in solar energy, solar cells and environmental as well as in technological applications. Doping of Mg and Al into ZnO offers an interesting way to alter various electronic, optical and structural properties. In this work, Mg doped (Zn0.98Al0.02O) films with different Mg concentrations (0, 1, 2, 4 and 6% were grown by spray pyrolysis technique and characterized by X ray diffraction (XRD) UV/VIS optical transmission spectroscopy and electrical measurement. XRD analysis of all samples indicates the presence of hexagonal crystal structure with a preferred orientation of the crystallites along the [002] direction perpendicular to the substrate and the absence of any other secondary phase. All samples exhibited interference fringe patterns in the visible region of transmittance spectra with an average transmission of >60% indicating a good optical quality of the deposited films. The optical studies demonstrate also that Mg doping induces an increase of the band gap energy. The dark electrical resistivity decreases with increasing Mg doping amount due to the increase of the grain size and the low electronegativity of Mg2+ than Zn2+",
"author_names": [
"Ouiame Karzazi",
"Lahcen Soussi",
"Ahmed Louardi",
"Abderrahim El Bachiri",
"Mohammed S Khaidar",
"Mohamade Monkade",
"Hassane Erguig",
"M Abu Taleb"
],
"corpus_id": 103787777,
"doc_id": "103787777",
"n_citations": 17,
"n_key_citations": 0,
"score": 0,
"title": "Transparent conducting properties of Mg and Al co doped ZnO thin films deposited by spray pyrolysis technique",
"venue": "Superlattices and Microstructures",
"year": 2019
}
] |
dynamics of competence based competition | [
{
"abstract": "Part I: Elements of a Theory of Competence Based Competition. A systems view of competence based competition (R. Sanchez, A. Heene) Strategic goals (R. Sanchez, H. Thomas) Industry dynamics in competence based competition (P. Gorman, H. Thomas, R. Sanchez) Part II: The Market Test for Competence From skills to competences: the play out of resource bundles across firms (W. Bogner, H. Thomas) Competitive analysis and competence based strategies in the hotel industry (M. Rispoli) Part III: Identifying and Building Competences. Developing and applying a process approach to competence analysis (M.A. Lewis, M.J. Gregory) Competence development by small firms in a vertically constrained industry structure (O. Jensen) Characterizing organizational competences: an industrial networks approaches (G. Easton, L. Araujo) Spinning off capabilities: competence development in knowledge intensive services (T. Elfring, G. Baven) Part IV: Leveraging Existing Competences. Flexible configuration strategies within Philips semiconductors: a strategic process of entrepreneurial revitalization (H.W. Volberda) From national to global product development competence in the telecommunications industry: structure and process in leveraging core capabilities (B.C. Winterscheid, S. McNabb) \"Quick Connect\" technologies for product creation: implications for competence based competition (R. Sanchez) Part V: Competence Building as the Driver of Industry Dynamics. The role of imitable vs. inimitable competences in the evolution of the semiconductor industry (R.W. Wright) Competence based competition and the evolution of strategic configurations (S. Tallman, D.L. Atchison) The role of international R&D in the competence building strategies of Japanese pharmaceutical firms (T. Roehl)",
"author_names": [
"Ron Sanchez",
"Aime Heene",
"Howard Thomas"
],
"corpus_id": 154792672,
"doc_id": "154792672",
"n_citations": 504,
"n_key_citations": 17,
"score": 1,
"title": "Dynamics of competence based competition: Theory and practice in the new strategic management",
"venue": "",
"year": 1997
},
{
"abstract": "",
"author_names": [
"Howard Thomas",
"Phil Gorman",
"Ron Sanchez"
],
"corpus_id": 166848495,
"doc_id": "166848495",
"n_citations": 11,
"n_key_citations": 0,
"score": 1,
"title": "Industry Dynamics in Competence Based Competition",
"venue": "",
"year": 1996
},
{
"abstract": "This article develops the reward punishment issue model of voting using a newly collated aggregate measure of issue competence in Britain between 1971 and 1997, revealing systematic differences between governing and opposition parties in the way citizens' evaluations of party competence are related to vote intention. Using monthly Gallup 'best party to handle the most important problem' and vote intention data, time series Grangercausation tests give support to a classic issue reward punishment model for incumbents. However, for opposition parties this reward punishment model does not hold: macro issue competence evaluations are Granger caused by changes in vote choice or governing party competence. An explanation is offered based upon the differentiating role of policy performance and informational asymmetries, and the implications are considered for comparative studies of voting, public opinion and for political party competition.",
"author_names": [
"Jane Green",
"Will Jennings"
],
"corpus_id": 154110717,
"doc_id": "154110717",
"n_citations": 85,
"n_key_citations": 1,
"score": 0,
"title": "The dynamics of issue competence and vote for parties in and out of power: An analysis of valence in Britain, 1979 1997",
"venue": "",
"year": 2012
},
{
"abstract": "In times of increasing use of project based structures, the capability of managing and organising projects becomes critical for competition. Previous research has documented the problems and possibilities of cross project learning and various mechanisms that organisations can use to stimulate and facilitate learning. Moreover, research on project competence and project capabilities has positioned these capabilities within a knowledge based theory of the firm. This paper tries to integrate these streams of research and attempts to broaden our current conceptual frameworks of how firms develop project competence. Based on an exploratory multiple case study of six firms, it is suggested that a more fine grained analysis of competence dynamics is required. We identify three different learning processes that contribute to the competence dynamics operating in project based organisations. The first one labelled \"shifting\" revolves around the major shifts in the project operations of the firm. It is suggested that such major shifts play an important role in laying the foundation and rejuvenating the challenges of project organising. The second learning process identified, labelled \"adapting\" focuses on the continuous learning that takes place within project operations of the firm, between project generation, project organising, project leadership and project teamwork. The third and final learning process \"leveraging\" emphasises the role of knowledge transfer across projects; across similar projects, across different types of projects. It is suggested that empirical research into competence dynamics in project based organisations should consider all three types of learning processes and further develop our understanding how these processes are linked to each other.",
"author_names": [
"Jonas Soderlund"
],
"corpus_id": 153325383,
"doc_id": "153325383",
"n_citations": 49,
"n_key_citations": 6,
"score": 1,
"title": "COMPETENCE DYNAMICS AND LEARNING PROCESSES IN PROJECT BASED FIRMS: SHIFTING, ADAPTING AND LEVERAGING",
"venue": "",
"year": 2008
},
{
"abstract": "COMPETENCE CONCEPTS FOR MANAGEMENT: The Emergence of the Competence Perspective in Management Research Competence Based Strategic Management Competence Theory Building MANAGING COMPETENCE DYNAMICS: Strategic Renewal within Complex Organizations Strategizing for Innovation Assessing the Organizational Capacity to Change Customers as the Originators for Change in Competence Building Strategic Defence and Competence Based Competition MANAGING COMPETENCE SYSTEMICS: Competence Levels within Firms Integrating Corporate Strategy and Competence Building Processes MANAGING ORGANIZATIONAL COGNITION: The Blind Spots of Competence Identification On Building and Leveraging Competencies across Organizational Borders MANAGING COMPETENCE HOLISTICALLY: Dynamic Corporate Coherence Reflection as a Building Block for Renewed Strategic Thinking Bringing the Environment into the Resource Based View of Strategy.",
"author_names": [
"Ron Sanchez",
"Aime Heene"
],
"corpus_id": 166890018,
"doc_id": "166890018",
"n_citations": 318,
"n_key_citations": 1,
"score": 2,
"title": "Competence based Strategic Management",
"venue": "",
"year": 1996
},
{
"abstract": "One of the most important challenges for economic policy in the 21st century is the ubiquitous process of globalisation. Traditional governance concepts based on sovereign nation states are increasingly called into question. This is the reason why alternative modes of governance such as network governance or the European Open Method of Coordination have become popular. However, the bulk of the relevant literature leaves the important issue of the dynamics of competence allocation unexplored. Most commonly it is left untouched and treated as a \"blackbox\" instead. We aim to show that the more general framework of multilevel systems of institutions can contribute to a deeper understanding of the dynamics that determine the allocation of competences in such systems and its evolution. We present an institutional economic analysis that views this allocation and its dynamics as the result of self interested, strategically behaving agents. Thus, we contribute towards a clarification of the \"blackbox\" of complex governance processes that will play a dominating role in 21st century's international economic policy. In this paper, we apply our approach to the specific field of EU competition policy. We examine in depth the fundamental changes currently going on in this field.",
"author_names": [
"Oliver Budzinski",
"Arndt Christiansen"
],
"corpus_id": 152638776,
"doc_id": "152638776",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Looking Inside the Blackbox: Competence Allocation in EU Competition Policy from an Actor Centred Perspective",
"venue": "",
"year": 2004
},
{
"abstract": "The social and didactic dynamics produced in implementations of the negotiation oriented and partly web based game aEURoeSurfing Global ChangeaEUR (SGC) was analyzed by independent experts after their observations in advanced interdisciplinary university courses. It could be empirically demonstrated that the intended didactics of SGC were successful; namely that they were grounded on aEURoeactive, self organized learningaEUR training of aEURoecompetence to actaEUR and on responsibility for both practicable and sustainable solutions for the future society. The outlay of SGC succeeds in equilibrating competition vs. consensus, self study vs. team work, sharpening the individual standpoint vs. readiness to compromise, differentiation into details vs. integration into a whole and hence mirrors professional realities. In this spirit, the architecture of SGC gives a framework for aEURoegame based learningaEUR along its five interactive game levels. The conclusion is made that the set of game rules acts as a boundary condition for expected processes of social self organization. The independent expert opinions express the importance of self responsibility, for example when defining team size (ideally 3 5) during the identification of students with a project relevant to real life, and with the trainer staying on the meta level without entering into student discussions. Hence, self organization in SGC allows for self responsibility.",
"author_names": [
"Gilbert Ahamer"
],
"corpus_id": 26133559,
"doc_id": "26133559",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Conclusions from Social Dynamics in Collaborative Environmental Didactics",
"venue": "Int. J. Technol. Educ. Mark.",
"year": 2015
},
{
"abstract": "The psychological contract as a manifestation of employment relationship needs to touch the motivational aspect of employees in line with the increasingly intense competition in recruiting and maintaining the talented worker, especially the millenial generation that currently occupies the largest portion of the workforce. Work characteristics and values of the millennial generation affect the dynamics of psychological contract management that has become more focused on flexibility and employability skill development. Millenial workers motivated to develop professional competence tend to like collaborative work environments. Based on the social constructivist paradigm, organizations can facilitate learning process of millennial workers through social interaction. The process of sharing knowledge becomes the focus of millenial workers in order to improve decision making ability, problem solving and communication building. The social constructivist approach becomes relevant in managing psychological contracts in the context of millennial workers, especially in encouraging their participation and contribution as a form of self esteem fulfillment and self actualization. This chapter presents practical implications of millenial worker collective activity in developing millennial worker knowledge, especially related to the organizational efforts in building learning culture. In addition, human resource practitioners are expected to be able to gain a valuable guidance in devising strategies to maintain millenial workers by focusing on building professional and social competence. There are also mentoring guidelines for career development based on millenial worker characteristics.",
"author_names": [
"Ade Irma Anggraeni"
],
"corpus_id": 169817159,
"doc_id": "169817159",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Millennial and Psychological Contract: Social Constructivist Approach",
"venue": "",
"year": 2018
},
{
"abstract": "Companies increasingly rely on external partners when starting their innovation initiatives. Emergent innovation ecosystems of heterogeneous actors proved to be successful in leveraging combined competence for the creation of the new ventures. However, constantly changing environment of simultaneous competition and cooperation coopetition, presents a challenge for the ecosystem management. Drawing on the network orchestration and coopetition research, I analyze management practices and coopetition dynamics in the digital creative industry in Northern Sweden. Based on the analysis, I offer two main contributions. First, I provide a detailed account of innovation ecosystem orchestration within the digital creative industry, including its chronological evolution and the challenges related to it. Second, the application of coopetition notion to the innovation ecosystem context brings forward tensions that should be further scrutinized in order to develop better management practices for such innovation networks.",
"author_names": [
"Vasili Mankevich"
],
"corpus_id": 106716659,
"doc_id": "106716659",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Managing Innovation Networks Exploring Coopetition Dynamics in Innovation Ecosystems",
"venue": "",
"year": 2014
},
{
"abstract": "In today's turbulent environment, customers are playing a more important role in competition, which can be reflected by customers as co producer, value co producer, or co developer of knowledge and competencies, etc. Accordingly, business priority should be given to what customers really value. Unlike previous studies, which emphasize market performance mainly from the internal or firm's perspective, this paper proposes that firms should prioritize customer focused performance, defined totally from an external perspective of targeted customers. The paper examines the important role of customer focused performance and its interactive relationships with other dimensions of the overall performance system, and goes further to analyze the components and dynamics of customer focused performance. Finally, attention is given to the dynamic competence building and leveraging process and its key elements, which determines the customer focused performance in perspective of resource based views. Important propositions are presented and future implications discussed.",
"author_names": [
"Yonggui Wang",
"Hing Po Lo"
],
"corpus_id": 141934251,
"doc_id": "141934251",
"n_citations": 108,
"n_key_citations": 3,
"score": 0,
"title": "Customer focused performance and the dynamic model for competence building and leveraging",
"venue": "",
"year": 2003
}
] |
Pulse-Width Modulated DC-DC Power Converters Solution manual | [
{
"abstract": "Preface. About the Author. List of Symbols. 1 Introduction. 1.1 Classification of Power Supplies. 1.2 Basic Functions of Voltage Regulators. 1.3 Power Relationships in DC DC Converters. 1.4 DC Transfer Functions of DC DC Converters. 1.5 Static Characteristics of DC Voltage Regulators. 1.6 Dynamic Characteristics of DC Voltage Regulators. 1.7 Linear Voltage Regulators. 1.8 Topologies of PWM DC DC Converters 1.9 Relationships among Current, Voltage, Energy, and Power. 1.10 Electromagnetic Compatibility. 1.11 Summary. 1.12 References. 1.13 Review Questions. 1.14 Problems. 2 BuckPWMDC DCConverter. 2.1 Introduction. 2.2 DC Analysis of PWM Buck Converter for CCM. 2.3 DC Analysis of PWM Buck Converter for DCM. 2.4 Buck Converter with Input Filter. 2.5 Buck Converter with Synchronous Rectifier. 2.6 Buck Converter with Positive Common Rail. 2.7 Tapped Inductor Buck Converters. 2.8 Multiphase Buck Converter. 2.9 Summary. 2.10 References. 2.11 Review Questions. 2.12 Problems. 3 Boost PWM DC DC Converter. 3.1 Introduction. 3.2 DC Analysis of PWM Boost Converter for CCM. 3.3 DC Analysis of PWM Boost Converter for DCM. 3.4 Bidirectional Buck and Boost Converters. 3.5 Tapped Inductor Boost Converters. 3.6 Duality. 3.7 Power Factor Correction. 3.8 Summary. 3.9 References. 3.10 Review Questions. 3.11 Problems. 4 Buck Boost PWM DC DC Converter. 4.1 Introduction. 4.2 DC Analysis of PWM Buck Boost Converter for CCM. 4.3 DC Analysis of PWM Buck Boost Converter for DCM. 4.4 Bidirectional Buck Boost Converter. 4.5 Synthesis of Buck Boost Converter. 4.6 Synthesis of Boost Buck (Cuk) Converter. 4.7 Noninverting Buck Boost Converters. 4.8 Tapped Inductor Buck Boost Converters. 4.9 Summary. 4.10 References. 4.11 Review Questions. 4.12 Problems. 5 Flyback PWM DC DC Converter. 5.1 Introduction. 5.2 Transformers. 5.3 DC Analysis of PWM Flyback Converter for CCM. 5.4 DC Analysis of PWM Flyback Converter for DCM. 5.5 Multiple Output Flyback Converter. 5.6 Bidirectional Flyback Converter. 5.7 Ringing in Flyback Converter. 5.8 Flyback Converter with Active Clamping. 5.9 Two Transistor Flyback Converter. 5.10 Summary. 5.11 References. 5.12 Review Questions. 5.13 Problems. 6 Forward PWM DC DC Converter. 6.1 Introduction. 6.2 DC Analysis of PWM Forward Converter for CCM. 6.3 DC Analysis of PWM Forward Converter for DCM. 6.4 Multiple Output Forward Converter. 6.5 Forward Converter with Synchronous Rectifier. 6.6 Forward Converters with Active Clamping. 6.7 Two Switch Forward Converter. 6.8 Summary. 6.9 References. 6.10 Review Questions. 6.11 Problems. 7 Half Bridge PWM DC DC Converter. 7.1 Introduction. 7.2 DC Analysis of PWM Half Bridge Converter for CCM. 7.3 DC Analysis of PWM Half Bridge Converter for DCM. 7.4 Summary. 7.5 References. 7.6 Review Questions. 7.7 Problems. 8 Full Bridge PWM DC DC Converter. 8.1 Introduction. 8.2 DC Analysis of PWM Full Bridge Converter for CCM. 8.3 DC Analysis of PWM Full Bridge Converter for DCM. 8.4 Phase Controlled Full Bridge Converter. 8.5 Summary. 8.6 References. 8.7 Review Questions. 8.8 Problems. 9 Push Pull PWM DC DC Converter. 9.1 Introduction. 9.2 DC Analysis of PWM Push Pull Converter for CCM. 9.3 DC Analysis of PWM Push Pull Converter for DCM. 9.4 Comparison of PWM DC DC Converters. 9.5 Summary. 9.6 References. 9.7 Review Questions. 9.8 Problems. 10 Small Signal Models of PWM Converters for CCM and DCM. 10.1 Introduction. 10.2 Assumptions. 10.3 Averaged Model of Ideal Switching Network for CCM. 10.4 Averaged Values of Switched Resistances. 10.5 Model Reduction. 10.6 Large Signal Averaged Model for CCM. 10.7 DC and Small Signal Circuit Linear Models of Switching Network for CCM. 10.8 Family of PWM Converter Models for CCM. 10.9 PWM Small Signal Switch Model for CCM. 10.10 Modeling of the Ideal Switching Network for DCM. 10.11 Averaged Parasitic Resistances for DCM. 10.12 Small Signal Models of PWM Converters for DCM. 10.13 Summary. 10.14 References. 10.15 Review Questions. 10.16 Problems. 11 Open Loop Small Signal Characteristics of Boost Converter for CCM. 11.1 Introduction. 11.2 DC Characteristics. 11.3 Open Loop Control to Output Transfer Function. 11.4 Delay in Open Loop Control to Output Transfer Function. 11.5 Open Loop Audio Susceptibility. 11.6 Open Loop Input Impedance. 11.7 Open Loop Output Impedance. 11.8 Open Loop Step Responses. 11.9 Summary. 11.10 References. 11.11 Review Questions. 11.12 Problems. 12 Voltage Mode Control of Boost Converter. 12.1 Introduction. 12.2 Circuit of Boost Converter with Voltage Mode Control. 12.3 Pulse Width Modulator. 12.4 Transfer Function of Modulator, Boost Converter Power Stage, and Feedback Network. 12.5 Error Amplifier. 12.6 Integral Single Lead Controller. 12.7 Integral Double Lead Controller. 12.8 Loop Gain. 12.9 Closed Loop Control to Output Voltage Transfer Function. 12.10 Closed Loop Audio Susceptibility. 12.11 Closed Loop Input Impedance. 12.12 Closed Loop Output Impedance. 12.13 Closed Loop Step Responses. 12.14 Closed Loop DC Transfer Functions. 12.15 Summary. 12.16 References. 12.17 Review Questions. 12.18 Problems. 13 Current Mode Control. 13.1 Introduction. 13.2 Principle of Operation of PWM Converters with Peak Current Mode Control. 13.3 Relationship between Duty Cycle and Inductor Current Slopes. 13.4 Instability of Closed Current Loop. 13.5 Slope Compensation. 13.6 Sample and Hold Effect on Current Loop. 13.7 Current Loop in s Domain. 13.8 Voltage Loop of PWM Converters with Current Mode Control. 13.9 Feedforward Gains in PWM Converters with Current Mode Control without Slope Compensation. 13.10 Feedforward Gains in PWM Converters with Current Mode Control and Slope Compensation. 13.11 Closed Loop Transfer Functions with Feedforward Gains. 13.12 Slope Compensation by Adding a Ramp to Inductor Current. 13.13 Relationships for Constant Frequency Current Mode On Time Control. 13.14 Summary. 13.15 References. 13.16 Review Questions. 13.17 Problems. 13.18 Appendix: Sample and Hold Modeling. 14 Current Mode Control of Boost Converter. 14.1 Introduction. 14.2 Open Loop Small Signal Transfer Functions. 14.3 Open Loop Step Responses of Inductor Current. 14.5 Closed Voltage Loop Transfer Functions. 14.6 Closed Loop Step Responses. 14.7 Closed Loop DC Transfer Functions. 14.8 Summary. 14.9 References. 14.10 Review Questions. 14.11 Problems. 15 Silicon and Silicon Carbide Power Diodes. 15.1 Introduction. 15.2 Electronic Power Switches. 15.3 Intrinsic Semiconductors. 15.4 Extrinsic Semiconductors. 15.5 Silicon and Silicon Carbide. 15.6 Physical Structure of Junction Diodes. 15.7 Static I V Diode Characteristic. 15.8 Breakdown Voltage of Junction Diodes. 15.9 Capacitances of Junction Diodes. 15.10 Reverse Recovery of pn Junction Diodes. 15.11 Schottky Diodes. 15.12 SPICE Model of Diodes. 15.13 Summary. 15.14 References. 15.15 Review Questions. 15.16 Problems. 16 Silicon and Silicon Carbide Power MOSFETs. 16.1 Introduction. 16.2 Physical Structure of Power MOSFETs. 16.3 Principle of Operation of Power MOSFETs. 16.4 Derivation of Power MOSFET Characteristics. 16.5 Power MOSFET Characteristics. 16.6 Mobility of Charge Carriers. 16.7 Short Channel Effects. 16.8 Aspect Ratio of Power MOSFETs. 16.9 Breakdown Voltage of Power MOSFETs. 16.10 Gate Oxide Breakdown Voltageof Power MOSFETs. 16.11 Resistance of Drift Region. 16.12 Figures of Merit. 16.13 On Resistance of Power MOSFETs. 16.14 Capacitances of Power MOSFETs. 16.15 Switching Waveforms. 16.16 SPICE Model of Power MOSFETs. 16.17 Insulated Gate Bipolar Transistors. 16.18 Heat Sinks. 16.19 Summary. 16.20 References. 16.21 Review Questions. 16.22 Problems. 17 Soft Switching DC DC Converters. 17.1 Introduction. 17.2 Zero Voltage Switching DC DC Converters. 17.3 Buck ZVS Quasi Resonant DC DC Converter. 17.4 Boost ZVS Quasi Resonant DC DC Converter. 17.5 Zero Current Switching DC DC Converters. 17.6 Boost ZCS Quasi Resonant DC DC Converter. 17.7 Multiresonant Converters. 17.8 Summary. 17.9 References. 17.10 Review Questions. 17.11 Problems. Appendix A Introduction to SPICE. Appendix B Introduction to MATLAB. Answers to Problems. Index.",
"author_names": [
"Marian K Kazimierczuk"
],
"corpus_id": 109665295,
"doc_id": "109665295",
"n_citations": 655,
"n_key_citations": 81,
"score": 1,
"title": "Pulse Width Modulated DC DC Power Converters",
"venue": "",
"year": 2008
},
{
"abstract": "",
"author_names": [
"Marian K Kazimierczuk"
],
"corpus_id": 63476315,
"doc_id": "63476315",
"n_citations": 331,
"n_key_citations": 0,
"score": 0,
"title": "Pulse Width Modulated DC DC Power Converters: Kazimierczuk/Pulse width Modulated DC DC Power Converters",
"venue": "",
"year": 2008
},
{
"abstract": "",
"author_names": [
"Marian K Kazimierczuk"
],
"corpus_id": 113885783,
"doc_id": "113885783",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Pulse Width Modulated DC DC Power Converters: Kazimierczuk/Pulse Width",
"venue": "",
"year": 2013
},
{
"abstract": "Visible light communication (VLC) has gained relevance during the last few years. It consists in using high brightness LEDs (HB LEDs) both for lighting and transmitting information by changing the light intensity rapidly. However, there are some bottlenecks that are slowing down the deployment of this technology. One of the most important problems is that the HB LED drivers proposed for addressing high data rates in VLC achieve poor power efficiency. Since these HB LED drivers must be able to reproduce fast current waveforms, the use of linear power amplifiers has been adopted, which clearly damages the power efficiency of HB LED lighting. In order to alleviate this problem, an HB LED driver made up of two DC DC power converters is presented in this work. One of them is responsible for performing the communication functionality by operating at high switching frequency (10 MHz) whereas the second converter fulfills the illumination functionality by ensuring a certain biasing point. The split of the power allows us to minimize the power delivered by the fast response DC DC power converter, which suffers from high switching losses. Thus, the overall efficiency can be maximized for each particular communication scenario and for scenarios with changing conditions (i.e. mobile transmitter and/or receiver, presence of mobile obstacles, etc. In this sense, how the lighting level and the communication signal power affect both the power efficiency and the communication efficiency is deeply analyzed in the experimental section. The implemented prototype achieves an overall efficiency around 90% In addition, the proposed VLC transmitter is able to reproduce a wide range of digital modulation schemes, including the preferred one for wireless communications: orthogonal frequency division multiplexing.",
"author_names": [
"Juan Rodriguez",
"Diego G Lamar",
"Pablo Fernandez Miaja",
"Daniel Garcia Aller",
"Javier Sebastian"
],
"corpus_id": 56596251,
"doc_id": "56596251",
"n_citations": 19,
"n_key_citations": 1,
"score": 0,
"title": "Power Efficient VLC Transmitter Based on Pulse Width Modulated DC DC Converters and the Split of the Power",
"venue": "IEEE Transactions on Power Electronics",
"year": 2019
},
{
"abstract": "This book is a comprehensive textbook in the areas of electrical, electronics, and telecommunications engineering. It consists of 17 chapters and two appendices. Some of the topics covered include: buck PWM DC DC converters; boost PWM DC DC converters; buck boost PWM DC DC converters; half bridge and full bridge converters; push pull PWM DC DC converters; open loop small signal characteristics of boost converters for CCM; current mode control of boost converters; silicon and silicon carbide power diodes; and soft switching DC DC converters. Appendix A is an introduction to SPICE and Appendix B provides an introduction to MATLAB. Answers to problems and the index are also included at the end of the book. The book is recommended for senior undergraduate and graduate students but also for practicing engineers working with switch mode power supplies, within applications such as computers, telecommunications, industrial electronic systems, automobile electronics, medical equipment, radars, and aerospace power technology.",
"author_names": [
"Marian P Kazmierkowski"
],
"corpus_id": 29870901,
"doc_id": "29870901",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Power converters and amplifiers (review of \"Pulse Width Modulated DC DC Power Converters\" by Kazimierczuk, M.K. 2008) [Book News]",
"venue": "IEEE Industrial Electronics Magazine",
"year": 2009
},
{
"abstract": "The electric vehicle (EV) charging systems employ dc dc power converters as EV chargers. Currently, the expected high penetration of electric vehicle (EV) demands for the integration of the renewable energy sources (RES) into the electric vehicle charging system as a promising solution to cut down the load on the electrical grid. These systems interface with RES by implementing dc dc power converters. Moreover, with the advent of high power dc charging, the charging efficiency is largely dependent on the performance of the power converters. Hence, to improve the charging, the soft switching dc dc converters are implemented to maintain low switching losses and to achieve high efficiency operation. This paper reviews the non isolated, soft switching dc dc power converters for EV charging application. For this purpose, different types of soft switching topologies, namely the snubber, the series resonant, the shunt resonant and the pulse frequency modulated converters are investigated. The advantages and the disadvantages associated with these converters are highlighted. Furthermore, to perform a comparative evaluation, the topologies are simulated in a standard simulation platform. Consequently, the relative standing of the converters depending on several parameters, i.e. the component count, the output voltage and current ripple, the soft switching range, and the power losses are established. Finally, based on these results, the optimum applicability of the converters in the EV charging application is determined. GUB JOURNAL OF SCIENCE AND ENGINEERING, Vol 6(1) Dec 2019 P 60 74",
"author_names": [
"Ratil Hasnat Ashique"
],
"corpus_id": 234653608,
"doc_id": "234653608",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "A Review of High Efficiency Non Isolated DC DC Power Converters for Electric Vehicle Charging Application",
"venue": "",
"year": 2020
},
{
"abstract": "Regan Zane and Dragan Maksimovic, Nonlinear Carrier Control for High Power Factor Rectifiers Based on Up Down Switching Converters, IEEE Transactions on Power Electronics, vol. 13, No. 2, Mar. 1998 pp. 213 221. Luigi Calderone, Lician Pinola and Vincenzo Varoli; Opti mal Feed Forward Compensation for PWM DC/DC Con verters with \"Linear\" and \"Ouadratic' Conversion Ratio, IEEE Transactions on Power Electronics, vol. 7, No. 2, Apr. 1992 pp. 349 355. Fakhralden A. Huliehel, Wei Tang, Fred C. Lee and Bo H. Cho; Modeling, Analysis, and Design of the Quasi Charge Control, IEEE Transactions on Power Electronics, vol. 10, No. 5, Sep. 1995, pp. 597 604. Wei Tang, Fred C. Lee, Raymond B. Ridley and Isaac Cohen, Charge Control: Modeling, Analysis, and Design, IEEE Transaction on Power Electronics, vol. 8, No. 4, Oct. 1993 pp. 396 403.",
"author_names": [
"Vincenzo Varoli",
"Fakhralden A Huliehel",
"Wei Tang"
],
"corpus_id": 73612345,
"doc_id": "73612345",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "PULSE. WIDTH MODULATED DC DC CONVERTER WITH A RAMP GENERATOR BACKGROUND OF THE INVENTION",
"venue": "",
"year": 2017
},
{
"abstract": "DC DC pulse width modulated (PWM) converters are nonlinear systems that require control circuits to obtain the desired output voltage. These control circuits are often designed using linearized models of the converters, so modeling is a relevant topic for the design of performing closed loop converters. In this paper, the nonlinear nature of DC DC PWM converters operated under continuous conduction mode (CCM) is considered. It is first shown how the exact periodic solutions can be analytically computed for the nonlinear converter model in the high frequency steady state operating condition. Also, a nonlinear variation model, which characterizes the closed loop dynamics, induced by perturbations of the steady state, is provided. The nonlinear models and the analytical periodic solutions are implemented in MATLAB and SIMULINK and applied to a boost converter subject to parasitic components. In particular, the behavior to step changes in duty cycle, input voltage, and load resistance are compared with the results obtained using small signal circuit averaging techniques.",
"author_names": [
"Alberto Reatti",
"Fabio Corti",
"Alberto Tesi",
"A Torlai",
"Marian K Kazimierczuk"
],
"corpus_id": 155823872,
"doc_id": "155823872",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Nonlinear Exact Analysis and Solution of Power Stage of DC DC PWM Boost Converter",
"venue": "2019 IEEE International Symposium on Circuits and Systems (ISCAS)",
"year": 2019
},
{
"abstract": "This study proposes an extension to the well known Fryze power theory, which allows the development of a mathematical procedure that defines a global factor for the active and non active power processing in pulse width modulated (PWM) dc dc converters. This global factor is the dc power factor. The proposed extension is a vector representation of periodic currents and voltages mapped into a k dimensional Euclidean space, which permits that all non active power of all converter elements to be collected into a single figure of merit. To validate the approaches, a 220 W prototype of an isolated dc dc Cuk converter architecture was implemented and evaluated. Experimental results have confirmed that both total non active power, the proposed dc power factor, and system efficiency are correlated. In the worst case of step down mode, the converter prototype presented the lowest total non active power of ~25 var for the turns ratio of 0.567, resulting in the highest dc power factor of 0.135 and prototype efficiency of 80.6% In step up mode, it was obtained the lowest total non active power of ~1.14 kvar for the turns ratio of 1.764, resulting in the highest efficiency of 88.3% and dc power factor of 0.145.",
"author_names": [
"Niwton Gabriel Feliciani dos Santos",
"Helio Leaes Hey",
"Jonatan Rafael Rakoski Zientarski",
"Mario L S Martins"
],
"corpus_id": 216478144,
"doc_id": "216478144",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Piecewise Fryze power theory analysis applied to PWM DC DC converters",
"venue": "",
"year": 2020
},
{
"abstract": "Pulse width modulated power converters are devices which transform voltages and currents between different levels to meet the requirements of the appliances. In contrast to conventional transformers, they use transistors and other semiconductor components to abruptly switch on and off the input voltage source to generate an output voltage or current which, averaged in time, equals the desired values. The so generated pulsed signal is usually filtered by an active or passive filter to suppress the high frequency components and thus smoothen the output. The numerical simulation of these devices is computationally expensive since with conventional time discretization very small time steps are necessary to properly represent the steep transients induced by the abrupt switching of the semiconductor devices. If the semiconductor behavior is idealized, a switch event detection is often necessary to prevent a failure of the time integration algorithm. In this dissertation a multirate approach is developed to efficiently tackle these problems. The idea is to split the solution of the ordinary differential or differential algebraic equations describing the power converters into slowly varying parts and fast varying parts. The output of the converter is represented as a sum of fast periodically varying ripples and a slowly varying envelope. The differential equations are, in a first step, reformulated into so called multirate partial differential equations (MPDEs) which allow to explicitly split the solution by associating the different components to different artificial time scales. The MPDEs are solved using a combination of two methods. First, a Galerkin approach is applied to solve along the fast time scale. Three different types of basis functions, namely PWM basis functions, PWM eigenfunctions and B spline basis functions, are employed. Second, a conventional time integration algorithm is used on the remaining differential equation system. It is assumed that the semiconductor switching behavior can be idealized as such that it can be represented by an ideal pulsed voltage source. The solution components along the fast varying time scale, i.e. the ripples, are represented by basis functions, which are specifically designed for this purpose. Since in some of the solution components the ripples are only continuous and not smooth, the basis functions take these points of C0 continuity at the proper position into account by construction. The MPDE approach is applied to different examples to demonstrate its accuracy and efficiency. It is applicable to single phase DC DC and DC AC power converters. If the power converter or the application consists of nonlinear elements the computational effort increases. For nonlinear elements, e.g. nonlinear inductors, a simplification is proposed which keeps the simulation efficient. To generate the pulsed excitation, a pulse width modulation (PWM) with constant switching frequency and varying duty cycle is applicable. It is generated by either sawtooth or triangle carriers. Both natural or regular sampling are supported. Besides circuit simulation the method is also applied to a field circuit coupled model.",
"author_names": [
"Andreas Pels"
],
"corpus_id": 213029154,
"doc_id": "213029154",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Multirate modeling and simulation of pulse width modulated power converters",
"venue": "",
"year": 2020
}
] |
photonic crystal machine learning | [
{
"abstract": "Using machine learning, we optimized an ultrasmall photonic crystal nanocavity to attain a high $Q$Q. Training data were collected via finite difference time domain simulation for models with randomly shifted holes, and a fully connected neural network (NN) was trained, resulting in a coefficient of determination between predicted and calculated values of 0.977. By repeating NN training and optimization of the $Q$Q value on the trained NN, the $Q$Q was roughly improved by a factor of 10 20 for various situations. Assuming a 180 nm thick semiconductor slab at a wavelength approximately 1550 nm, we obtained $Q={1}{011}{400}$Q=1,011,400 in air; 283,200 in a solution, which was suitable for biosensing; and 44,600 with a nanoslot for high sensitivity. Important hole positions were also identified using the linear Lasso regression algorithm.",
"author_names": [
"Ryotaro Abe",
"Taichi Takeda",
"Ryo Shiratori",
"Shinichi Shirakawa",
"S Saito",
"Toshihiko Baba"
],
"corpus_id": 214562005,
"doc_id": "214562005",
"n_citations": 5,
"n_key_citations": 0,
"score": 1,
"title": "Optimization of an H0 photonic crystal nanocavity using machine learning",
"venue": "",
"year": 2020
},
{
"abstract": "By utilizing random localization patterns as training data for machine learning, we achieved a 0.2 nm wavelength resolution with a fabricated photonic crystal wavemeter, which greatly exceeds the limit imposed by the fabrication.",
"author_names": [
"Jocelyn Hofs",
"Takumasa Kodama",
"Shengji Jin",
"Takasumi Tanabe"
],
"corpus_id": 221717704,
"doc_id": "221717704",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Breaking the Fabrication Determined Resolution Limit of Photonic Crystal Wavemeter by Machine Learning",
"venue": "2020 Conference on Lasers and Electro Optics (CLEO)",
"year": 2020
},
{
"abstract": "Abstract In this paper, a machine learning (ML) based approach is described to design a photonic crystal (PhC) gas sensor for identification and estimation of three greenhouse gases, namely S F 6 C H 4 and C O 2 Exploiting the refractive index dependence of the defect layer positions in the photonic bandgap (PBG) in the transmission spectrum of a PhC, structures are proposed to detect different types of gases. First, a pre trained classifier is used to identify the gases. Support Vector Machine (SVM) and Random Forest (RF) classifiers are used for performance evaluation with hyper parameter optimization. Random forest classifier yields the highest accuracy of 100% for the gas identification stage. In the next step, the densities of the gases are predicted using three pre trained artificial neural networks (ANNs) separately for each of the gases. The results show that the present approach helps design of a precision gas sensor even using a simple PhC structure.",
"author_names": [
"Alekhya Ghosh",
"Arghadeep Pal",
"Nikhil Ranjan Das"
],
"corpus_id": 213120463,
"doc_id": "213120463",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "An approach to design photonic crystal gas sensor using machine learning",
"venue": "",
"year": 2020
},
{
"abstract": "We train a neural network to predict the optical properties (center wavelength l0, linewidth, sensitivity S) of photonic crystal slab structures. We are able to faithfully model the results to within 1% for l0 and S.",
"author_names": [
"Eric Yi Zhu",
"Li Qian",
"Ofer Levi"
],
"corpus_id": 229528811,
"doc_id": "229528811",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Identifying Optimal Photonic Crystal Sensor Designs with Machine Learning",
"venue": "",
"year": 2020
},
{
"abstract": "Photonic crystal fibers (PCFs) are the specialized optical waveguides that led to many interesting applications ranging from nonlinear optical signal processing to high power fiber amplifiers. In this paper, machine learning techniques are used to compute various optical properties including effective index, effective mode area, dispersion and confinement loss for a solid core PCF. These machine learning algorithms based on artificial neural networks are able to make accurate predictions of above mentioned optical properties for usual parameter space of wavelength ranging from 0.5 1.8 um, pitch from 0.8 2.0 um, diameter by pitch from 0.6 0.9 and number of rings as 4 or 5 in a silica solid core PCF. We demonstrate the use of simple and fast training feed forward artificial neural networks that predicts the output for unknown device parameters faster than conventional numerical simulation techniques. Computation runtimes required with neural networks (for training and testing) and Lumerical MODE solutions are also compared.",
"author_names": [
"Sunny Chugh",
"Aamir Gulistan",
"Souvik Ghosh",
"B M Azizur Rahman"
],
"corpus_id": 209464240,
"doc_id": "209464240",
"n_citations": 17,
"n_key_citations": 1,
"score": 0,
"title": "Machine learning approach for computing optical properties of a photonic crystal fiber.",
"venue": "Optics express",
"year": 2019
},
{
"abstract": "A photonic crystal enhanced fluorescence imaging immunoassay biosensor is capable of detecting NT proBNP as a cardiovascular biomarker at various concentrations. Utilizing machine learning algorithms, we create a predictive model for the analyte quantification. (c) 2019 The Author(s)",
"author_names": [
"Kenneth J Squire",
"Yaodong Zhao",
"Ai-ling Tan",
"Kundan Sivashanmugan",
"Joseph A Kraai",
"Gregory L Rorrer",
"Alan X Wang"
],
"corpus_id": 203082873,
"doc_id": "203082873",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Photonic Crystal Enhanced Fluorescence Imaging of Cardiovascular Biomarker with Machine Learning Analysis",
"venue": "",
"year": 2019
},
{
"abstract": "A photonic crystal enhanced fluorescence imaging immunoassay biosensor is capable of detecting NT proBNP as a cardiovascular biomarker at various concentrations. Utilizing machine learning algorithms, we create a predictive model for the analyte quantification. (c) 2019 The Author(s)",
"author_names": [
"Kenneth J Squire",
"Y A Zhao",
"Ai-ling Tan",
"Kundan Sivashanmugan",
"Joseph A Kraai",
"Gregory L Rorrer",
"Alan X Wang"
],
"corpus_id": 164514523,
"doc_id": "164514523",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Photonic Crystal Enhanced Fluorescence Imaging of Cardiovascular Biomarker with Machine Learning Analysis",
"venue": "2019 Conference on Lasers and Electro Optics (CLEO)",
"year": 2019
},
{
"abstract": "When myocardial walls experience stress due to cardiovascular diseases, like heart failure, hormone N terminal pro B type natriuretic peptide (NT proBNP) is secreted into the blood. Early detection of NT proBNP can assist diagnosis of heart failure and enable early medical intervention. A simple, cost effective detection technique such as the widely used fluorescence imaging immunoassay is yet to be developed to detect clinically relevant levels of NT proBNP. In this work, we demonstrate photonic crystal enhanced fluorescence imaging immunoassay using diatom biosilica, which is capable of detecting low levels of NT proBNP in solution with the concentration range of 0~100 pg/mL. By analyzing the fluorescence images in the spatial and spatial frequency domain with principle component analysis (PCA) and partial least squares regression (PLSR) algorithms, we create a predictive model that achieves great linearity with a validation R2 value of 0.86 and a predictive root mean square error of 14.47, allowing for good analyte quantification. To demonstrate the potential of the fluorescence immunoassay biosensor for clinical usage, we conducted qualitative screening of high and low concentrations of NT proBNP in human plasma. A more advanced machine learning algorithm, the support vector machine classification, was paired with the PCA and trained by 160 fluorescence images. In the 40 testing images, we achieved excellent specificity of 93% as well as decent accuracy and sensitivity of 78% and 65% respectively. Therefore, the photonic crystal enhanced fluorescence imaging immunoassay reported in this article is feasible to screen clinically relevant levels of NT proBNP in body fluid and evaluate the risk of heart failure.",
"author_names": [
"Kenneth J Squire",
"Yong Zhao",
"Ai-ling Tan",
"Kundan Sivashanmugan",
"Joseph A Kraai",
"Gregory L Rorrer",
"Alan X Wang"
],
"corpus_id": 133271183,
"doc_id": "133271183",
"n_citations": 10,
"n_key_citations": 1,
"score": 0,
"title": "Photonic Crystal Enhanced Fluorescence Imaging Immunoassay for Cardiovascular Disease Biomarker Screening with Machine Learning Analysis.",
"venue": "Sensors and actuators. B, Chemical",
"year": 2019
},
{
"abstract": "",
"author_names": [
"Takashi Asano"
],
"corpus_id": 199819344,
"doc_id": "199819344",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Machine learning based simultaneous optimization of Q factors of two modes in a photonic crystal nanocavity aimed for the application to Raman silicon laser",
"venue": "",
"year": 2019
},
{
"abstract": "Abstract The prediction and design of photonic features have traditionally been guided by theory driven computational methods, spanning a wide range of direct solvers and optimization techniques. Motivated by enormous advances in the field of machine learning, there has recently been a growing interest in developing complementary data driven methods for photonics. Here, we demonstrate several predictive and generative data driven approaches for the characterization and inverse design of photonic crystals. Concretely, we built a data set of 20,000 two dimensional photonic crystal unit cells and their associated band structures, enabling the training of supervised learning models. Using these data set, we demonstrate a high accuracy convolutional neural network for band structure prediction, with orders of magnitude speedup compared to conventional theory driven solvers. Separately, we demonstrate an approach to high throughput inverse design of photonic crystals via generative adversarial networks, with the design goal of substantial transverse magnetic band gaps. Our work highlights photonic crystals as a natural application domain and test bed for the development of data driven tools in photonics and the natural sciences.",
"author_names": [
"Thomas Christensen",
"Charlotte Loh",
"Stjepan Picek",
"Domagoj Jakobovic",
"Li Jing",
"Sophie Fisher",
"Vladimir Ceperic",
"John D Joannopoulos",
"Marin Soljacic"
],
"corpus_id": 222004306,
"doc_id": "222004306",
"n_citations": 13,
"n_key_citations": 0,
"score": 0,
"title": "Predictive and generative machine learning models for photonic crystals",
"venue": "",
"year": 2020
}
] |
Variable Selection Under Missing Values and Unlabeled Data in Semiconductor Processes | [
{
"abstract": "Manufacturing semiconductor wafers involves many sequential processes, and each process has various equipment related variables or factors, which results in high dimensional data. However, measuring the quality of all wafers is time and cost intensive, and only a small proportion of the wafers is labeled. Further, equipment factors are not always measured by sensors due to the complicated process. Variable selection, which is performed to reduce the dimensionality of the input variable space while improving or preserving regression performance by selecting important input factors, plays an important role in regression problems. We propose a variable selection procedure to find the main equipment factors that affect in process wafer quality in consideration of the following issues: 1) imputation for missing values; 2) semi supervised regression for unlabeled data; and 3) redundancy among variables. In the proposed procedure, partial least squares and least absolute shrinkage and selection operator regression are utilized as prediction models. Experiments using two semiconductor equipment datasets were conducted to evaluate the performance of the proposed procedure.",
"author_names": [
"Kyung-jun Kim",
"Kyu-Jin Kim",
"Chi-Hyuck Jun",
"Il-Gyo Chong",
"Geun-Young Song"
],
"corpus_id": 59526007,
"doc_id": "59526007",
"n_citations": 4,
"n_key_citations": 0,
"score": 1,
"title": "Variable Selection Under Missing Values and Unlabeled Data in Semiconductor Processes",
"venue": "IEEE Transactions on Semiconductor Manufacturing",
"year": 2019
},
{
"abstract": "SUMMARY VarSelLCM allows a full model selection (detection of the relevant features for clustering and selection of the number of clusters) in model based clustering, according to classical information criteria. Data to be analyzed can be composed of continuous, integer and/or categorical features. Moreover, missing values are managed, without any pre processing, by the model used to cluster with the assumption that values are missing completely at random. Thus, VarSelLCM also allows data imputation by using mixture models. A Shiny application is implemented to easily interpret the clustering results. AVAILABILITY AND IMPLEMENTATION VarSelLCM is available to download at https:/CRAN.R project.org/package=VarSelLCM/ TUTORIAL vignette is available online at http:/varsellcm.r forge.r project.org/ SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.",
"author_names": [
"Matthieu Marbac",
"Mohammed Sedki"
],
"corpus_id": 52173418,
"doc_id": "52173418",
"n_citations": 15,
"n_key_citations": 1,
"score": 0,
"title": "VarSelLCM: an R/C+ package for variable selection in model based clustering of mixed data with missing values",
"venue": "Bioinform.",
"year": 2019
},
{
"abstract": "Abstract Longitudinal data with multilevel structures are commonly collected when following up subjects in clusters over a period of time. Missing values and variable selection issues are common for such data. Biased results may be produced if incompleteness of data is ignored in the analysis. On the other hand, incorporating a large number of irrelevant covariates into inferential procedures may lead to difficulty in computation and interpretation. A unified penalized composite likelihood framework is developed to handle data with missingness and variable selection issues. It is flexible to handle the situation where responses and covariates are missing not simultaneously under the assumption of missing not at random. The method is justified both rigorously with theoretical results and numerically with simulation studies. The method is also applied to the Waterloo Smoking Prevention Project data.",
"author_names": [
"Haocheng Li",
"Di Shu",
"Wenqing He",
"Grace Y Yi"
],
"corpus_id": 127408009,
"doc_id": "127408009",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Variable selection via the composite likelihood method for multilevel longitudinal data with missing responses and covariates",
"venue": "Comput. Stat. Data Anal.",
"year": 2019
},
{
"abstract": "We consider the problem of model based clustering in the presence of many correlated, mixed continuous, and discrete variables, some of which may have missing values. Discrete variables are treated with a latent continuous variable approach, and the Dirichlet process is used to construct a mixture model with an unknown number of components. Variable selection is also performed to identify the variables that are most influential for determining cluster membership. The work is motivated by the need to cluster patients thought to potentially have autism spectrum disorder on the basis of many cognitive and/or behavioral test scores. There are a modest number of patients (486) in the data set along with many (55) test score variables (many of which are discrete valued and/or missing) The goal of the work is to (1) cluster these patients into similar groups to help identify those with similar clinical presentation and (2) identify a sparse subset of tests that inform the clusters in order to eliminate unnecessary testing. The proposed approach compares very favorably with other methods via simulation of problems of this type. The results of the autism spectrum disorder analysis suggested 3 clusters to be most likely, while only 4 test scores had high >0.5) posterior probability of being informative. This will result in much more efficient and informative testing. The need to cluster observations on the basis of many correlated, continuous/discrete variables with missing values is a common problem in the health sciences as well as in many other disciplines.",
"author_names": [
"Curtis B Storlie",
"Scott M Myers",
"Slavica K Katusic",
"Amy L Weaver",
"Robert G Voigt",
"Paul E Croarkin",
"Ruth E Stoeckel",
"J David Port"
],
"corpus_id": 21686928,
"doc_id": "21686928",
"n_citations": 6,
"n_key_citations": 0,
"score": 0,
"title": "Clustering and variable selection in the presence of mixed variable types and missing data.",
"venue": "Statistics in medicine",
"year": 2018
},
{
"abstract": "Abstract Semiconductor wafers are fabricated through sequential process steps. Some process steps have a strong relationship with wafer yield, and these are called critical process steps. Because wafer yield is a key performance index in wafer fabrication, the critical process steps should be carefully selected and managed. This paper proposes a systematic and data driven approach for identifying the critical process steps. The proposed method considers troublesome properties of the data from the process steps such as imbalanced data, missing values, and random sampling. As a case study, we analyzed hypothetical operational data and confirmed that the proposed method works well.",
"author_names": [
"Dong-Hee Lee",
"Jin Kyung Yang",
"Cho Heui Lee",
"Kwang-Jae Kim"
],
"corpus_id": 199085827,
"doc_id": "199085827",
"n_citations": 18,
"n_key_citations": 0,
"score": 0,
"title": "A data driven approach to selection of critical process steps in the semiconductor manufacturing process considering missing and imbalanced data",
"venue": "Journal of Manufacturing Systems",
"year": 2019
},
{
"abstract": "The regularization approach for variable selection was well developed for a completely observed data set in the past two decades. In the presence of missing values, this approach needs to be tailored to different missing data mechanisms. In this paper, we focus on a flexible and generally applicable missing data mechanism, which contains both ignorable and nonignorable missing data mechanism assumptions. We show how the regularization approach for variable selection can be adapted to the situation under this missing data mechanism. The computational and theoretical properties for variable selection consistency are established. The proposed method is further illustrated by comprehensive simulation studies and real data analyses, for both low and high dimensional settings.",
"author_names": [
"Jiwei Zhao",
"Yongxiang Yang",
"Yang Ning"
],
"corpus_id": 56306070,
"doc_id": "56306070",
"n_citations": 15,
"n_key_citations": 0,
"score": 0,
"title": "Penalized pairwise pseudo likelihood for variable selection with nonignorable missing data",
"venue": "",
"year": 2017
},
{
"abstract": "Introduction In many studies, covariates are not always fully observed because of missing data process. Usually, subjects with missing data are excluded from the analysis but the number of covariates can be greater than the size of the sample when the number of removed subjects is high. Subjective selection or imputation procedures are used but this leads to biased or powerless models. The aim of our study was to develop a method based on the selection of the nearest covariate to the centroid of a homogeneous cluster of covariates. We applied this method to a forensic medicine data set to estimate the age of aborted fetuses. Analysis Methods We measured 46 biometric covariates on 50 aborted fetuses. But the covariates were complete for only 18 fetuses. First, to obtain homogeneous clusters of covariates we used a hierarchical cluster analysis. Second, for each obtained cluster we selected the nearest covariate to the centroid of the cluster, maximizing the sum of correlations (the centroid criterion) Third, with the covariate selected this way, the sample size was sufficient to compute a classical linear regression model. We have shown the almost sure convergence of the centroid criterion and simulations were performed to build its empirical distribution. We compared our method to a subjective deletion method, two simple imputation methods and to the multiple imputation method. Results The hierarchical cluster analysis built 2 clusters of covariates and 6 remaining covariates. After the selection of the nearest covariate to the centroid of each cluster, we computed a stepwise linear regression model. The model was adequate (R2=90.02% and the cross validation showed low prediction errors (2.23 10 3) The empirical distribution of the criterion provided empirical mean (31.91) and median (32.07) close to the theoretical value (32.03) The comparisons showed that deletion and simple imputation methods provided models of inferior quality than the multiple imputation method and the centroid method. Conclusion When the number of continuous covariates is greater than the sample size because of missing process, the usual procedures are biased. Our selection procedure based on the centroid criterion is a valid alternative to compose a set of predictors.",
"author_names": [
"Jean Gaudart",
"Pascal Adalian",
"Georges Leonetti"
],
"corpus_id": 92087535,
"doc_id": "92087535",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Predictive model in the presence of missing data: the centroid criterion for variable selection",
"venue": "",
"year": 2018
},
{
"abstract": "Abstract Motivation Recent advances in high dimensional phenotyping bring time as an extra dimension into the phenotypes. This promotes the quantitative trait locus (QTL) studies of function valued traits such as those related to growth and development. Existing approaches for analyzing functional traits utilize either parametric methods or semi parametric approaches based on splines and wavelets. However, very limited choices of software tools are currently available for practical implementation of functional QTL mapping and variable selection. Results We propose a Bayesian Gaussian process (GP) approach for functional QTL mapping. We use GPs to model the continuously varying coefficients which describe how the effects of molecular markers on the quantitative trait are changing over time. We use an efficient gradient based algorithm to estimate the tuning parameters of GPs. Notably, the GP approach is directly applicable to the incomplete datasets having even larger than 50% missing data rate (among phenotypes) We further develop a stepwise algorithm to search through the model space in terms of genetic variants, and use a minimal increase of Bayesian posterior probability as a stopping rule to focus on only a small set of putative QTL. We also discuss the connection between GP and penalized B splines and wavelets. On two simulated and three real datasets, our GP approach demonstrates great flexibility for modeling different types of phenotypic trajectories with low computational cost. The proposed model selection approach finds the most likely QTL reliably in tested datasets. Availability and implementation Software and simulated data are available as a MATLAB package 'GPQTLmapping' and they can be downloaded from GitHub (https:/github.com/jpvanhat/GPQTLmapping) Real datasets used in case studies are publicly available at QTL Archive. Supplementary information Supplementary data are available at Bioinformatics online.",
"author_names": [
"Jarno Vanhatalo",
"Zitong Li",
"Mikko J Sillanpaa"
],
"corpus_id": 73489054,
"doc_id": "73489054",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "A Gaussian process model and Bayesian variable selection for mapping function valued quantitative traits with incomplete phenotypic data",
"venue": "Bioinform.",
"year": 2019
},
{
"abstract": "The selection of variables with high dimensional and missing data is a major challenge and very few methods are available to solve this problem. Here we propose a new method adaptive Bayesian SLOPE which is an extension of the SLOPE method of sorted $l_1$ regularization within a Bayesian framework and which allows to simultaneously estimate the parameters and select variables for large data despite missing values. The method follows the idea of the Spike and Slab LASSO, but replaces the Laplace mixture prior with the frequentist motivated \"SLOPE\" prior, which targets control of the False Discovery Rate. The regression parameters and the noise variance are estimated using stochastic approximation EM algorithm, which allows to incorporate missing values as well as latent model parameters, like the signal magnitude and its sparsity. Extensive simulations highlight the good behavior in terms of power, FDR and estimation bias under a wide range of simulation scenarios. Finally, we consider an application of severely traumatized patients from Paris hospitals to predict the level of platelet, and demonstrate, beyond the advantage of selecting relevant variables, which is crucial for interpretation, excellent predictive capabilities. The methodology is implemented in the R package ABSLOPE, which incorporates C+ code to improve the efficiency of the proposed method.",
"author_names": [
"Wei Jiang",
"Malgorzata Bogdan",
"Julie Josse",
"Blazej Miasojedow",
"Veronika Rockova",
"Traumabase Group"
],
"corpus_id": 202577373,
"doc_id": "202577373",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "Adaptive Bayesian SLOPE High dimensional Model Selection with Missing Values",
"venue": "",
"year": 2019
},
{
"abstract": "Longitudinal data are common in various sectors where repeated measurements on a dependent variable are collected for all subjects. Missing data pattern are caused when most planned measurements are unavailable for some subjects. The dropout process may cause three missing values mechanism, namely: Missing Completely at Random (MCAR) Missing at Random (MAR) and Missing Not at Random (MNAR) The missing values have influence on quantitative study that can be serious, leading to biased estimates of parameters, information loss, reduced statistical power, increased standard errors, and weakened generalization of findings. This thesis compared the performance of seven (7) techniques of imputing missing values under the assumptions of MCAR and MAR mechanisms. The study adopted the little's test to check whether a dataset with missing values is MCAR or MAR. The techniques for solving missing values problems were compared using the Generalized Estimating Equation (GEE) model for the complete dataset, the coefficient of determination and root mean squared error (RMSE) The study discovered that when large (above 10% or small (below 10% values are missing at random (MAR) it is important to use multiple imputation or expectation maximization to replace missing values in the dataset. The pairwise deletion is the best under MCAR mechanism. Listwise deletion and the hot deck imputation methods performed poorly under the MCAR mechanism. It is recommended that researchers should understand the patterns of missing values in dataset and clearly recognize missing data problems and the situations under which they occurred. However, further research is needed to find a better method for imputing missing not at random (MNAR) with multiple imputation. This thesis focused on missing values in a longitudinal dataset. However, future research using categorical data is a step in right the direction. iii University of Ghana http:/ugspace.ug.edu.gh",
"author_names": [
"Lotsi Anani",
"Louis Asiedu",
"Johnson Katsekpor"
],
"corpus_id": 125178909,
"doc_id": "125178909",
"n_citations": 3,
"n_key_citations": 1,
"score": 0,
"title": "Comparison of Imputation Methods for Missing Values in Longitudinal Data Under Missing Completely at Random (mcar) mechanism",
"venue": "",
"year": 2017
}
] |
nanocomposite materials: fabrication and its applications | [
{
"abstract": "Zinc oxide (ZnO) is one of the most commonly used semiconductor materials for various applications, namely as photocatalysts, gas sensors, antimicrobial substances, and photovoltaic cells. The performance of the particles is greatly influenced by the morphology and the optical properties of the particles itself. To improve the performance of ZnO, one method which can be applied is by doping support with other semiconductor materials, such as TiO2. This is caused by electron transfers between ZnO and TiO2 which are able to enhance the stability of ZnO and the electron mobility of TiO2. Therefore, the electron hole recombination can be inhibited by this mechanism. Fabrication of ZnO TiO2 can be prepared by several methods, which is gas or liquid phases and solid phase. Spray pyrolysis, chemical vapor deposition, micro arc oxidation, electrospinning and electron beam evaporation are preparation method for gas phase synthesis, while sol gel, hydrothermal, precipitation, solution combustion, pulse plating, and wet impregnation are for liquid phases. In this study, the fabrication methods of ZnO TiO2 and its application have been reviewed as well as the factors that affect the morphology, performance, and the stability of ZnO TiO2 nanocomposite. This review is conducted by comparing the analysis results with their performances. It is clearly found that there is an optimum condition for obtaining the best photocatalytic performance by adjusting the ratio of ZnO to TiO2. Furthermore, ratio of ZnO:TiO2 concentration on antimicrobial activity shows a linear performance, and it is obviously observed that the ZnO TiO2 nanocomposite shows a better performance compared to the pristine ZnO or TiO2 in various applications. We believe that this review will provide valuable information and new insights into possible fabrication methods of ZnO TiO2 nanocomposite materials, which can be used in many applications.",
"author_names": [
"K Kusdianto",
"D F Nugraha",
"A Sekarnusa",
"Suci Madhania",
"Siti Machmudah",
"Suminto Winardi"
],
"corpus_id": 234019089,
"doc_id": "234019089",
"n_citations": 0,
"n_key_citations": 0,
"score": 1,
"title": "ZnO TiO2 nanocomposite materials: fabrication and its applications",
"venue": "",
"year": 2021
},
{
"abstract": "Abstract The nanocomposite rods shows well known properties compared with nano structured materials for various applications like light emitting diodes, electron field emitters, solar cells, optoelectronics, sensors, transparent conductors and fabrication of nano devices. Present paper investigates the properties of ZnO/TiO 2 nanocomposite rods. The bi component of ZnO/TiO 2 nanocomposite rods was synthesized by microwave assisted method which is very simple, rapid and uniform in heating. The frequency of microwaves 2.45 GHz was used and temperature maintained 180 degC. Zinc acetate and titanium isopropoxide precursors were used in the preparation. The obtained ZnO/TiO 2 nanocomposite rods were annealed at 500 degC and 600 degC. ZnO/TiO 2 nanocomposite rods have been characterized by X ray Diffraction (XRD) for average crystallite size and phase of the composite material, Particle Size Analyser (PSA) for average particle size, Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) for morphology study, Energy Dispersive X ray Spectrometry (EDX) for elemental analysis, and Thermal Gravimetric and Differential Thermal Analysis (TG DTA) for thermal property.",
"author_names": [
"Ch Ashok",
"K Venkateswara Rao"
],
"corpus_id": 123179179,
"doc_id": "123179179",
"n_citations": 31,
"n_key_citations": 2,
"score": 0,
"title": "ZnO/TiO2 nanocomposite rods synthesized by microwave assisted method for humidity sensor application",
"venue": "",
"year": 2014
},
{
"abstract": "Zinc oxide nanoparticles have been used in various applications because of its unique physical and chemical properties. Unfortunately, the performance of pristine ZnO is inhibited by electron hole recombination. The zinc oxide performance can be improved by metal doping to enhance its properties. This review paper provides summary of the synthesis and application of zinc oxide doped by silver (Ag) using different synthesis via gas phase methods. From this review, synthesis parameters that will affect the ZnO Ag nanoparticle and its application will be concluded. The gas phase synthesis methods include flame spray pyrolysis, spray pyrolysis, sputtering, plasma enhanced chemical vapor deposition, electron beam evaporation, atomic layer deposition and electrospinning. It is clearly observed that the morphology, crystallinity, and performance of ZnO Ag nanocomposite is significantly affected by the fabrication method. The precursors used, spray rate, deposition rate, precursor concentration, deposition time, morphology of the nanoparticle and deposition or annealing temperature affect the performance capability of ZnO Ag. We believe that this review paper will provide valuable information and new insights into possible fabrication methods of ZnO Ag nanocomposite materials in the gas phase, which can be used for many applications as photocatalyst, anti microbial applications, catalyst for hydrogen production as well as in dye sensitized solar cells and gas sensors.",
"author_names": [
"K Kusdianto",
"T D Sari",
"Maulana Agung Laksono",
"Suci Madhania",
"Suminto Winardi"
],
"corpus_id": 234016907,
"doc_id": "234016907",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Fabrication and application of ZnO Ag nanocomposite materials prepared by gas phase methods",
"venue": "",
"year": 2021
},
{
"abstract": "The search for alternative energy sources has led us to develop solar energy as one of the primary solutions. Infallible Preparation of Titanium Dioxide (TiO2) by Sol Gel technique then embedded into polystyrene (PS) with different ratios to fabricate PS/TiO2 nanocomposite for solar cell usage. The Crystalline framework of TiO2 and PS/TiO2 were investigated through X ray diffraction (XRD) in determining of its crystal size. UV Visible Spectroscopy gave the relation between the absorbance and wavelength of the materials. The evolution of electrical properties of PS/TiO2 nanocomposite is investigated to set the optimum parameter in fabrication PS/TiO2 as solar cell materials.The search for alternative energy sources has led us to develop solar energy as one of the primary solutions. Infallible Preparation of Titanium Dioxide (TiO2) by Sol Gel technique then embedded into polystyrene (PS) with different ratios to fabricate PS/TiO2 nanocomposite for solar cell usage. The Crystalline framework of TiO2 and PS/TiO2 were investigated through X ray diffraction (XRD) in determining of its crystal size. UV Visible Spectroscopy gave the relation between the absorbance and wavelength of the materials. The evolution of electrical properties of PS/TiO2 nanocomposite is investigated to set the optimum parameter in fabrication PS/TiO2 as solar cell materials.",
"author_names": [
"Maytham Qabel Hamzah",
"Abdullah Hasan Jabbar",
"Salim Oudah Mezan",
"Alaa Nihad Tuama",
"Mohd Arif Agam"
],
"corpus_id": 202942082,
"doc_id": "202942082",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Fabrications of PS/TiO2 nanocomposite for solar cells applications",
"venue": "",
"year": 2019
},
{
"abstract": "TiO2, TiO2 ZnO (TZ) nanocomposite and PANI (Poly aniline) have been synthesized by simple sol gel and direct chemical method, respectively, for the application in Dye Sensitized Solar Cell (DSSC) Structural, morphological and optical analyses were carried out using XRD, SEM, EDAX, PL and FTIR. PANI film has been fabricated for solid state DSSC. The photovoltaic performance has been checked for both liquid state and solid state in outdoor and indoor environmental condition. The results show that for TZ showed better performance compared to the monophasic TiO2. Stability test showed that the solid state DSSC shows a better stability under constant illumination. Liquid state DSSC loses its efficiency by about 52.5 while solid state to DSSC by about 13.3 after 5 h of constant illumination.",
"author_names": [
"Bibha Boro",
"Biju Mani Rajbongshi",
"Sanjoy Kumar Samdarshi"
],
"corpus_id": 138727034,
"doc_id": "138727034",
"n_citations": 11,
"n_key_citations": 0,
"score": 0,
"title": "Synthesis and fabrication of TiO2 ZnO nanocomposite based solid state dye sensitized solar cell",
"venue": "Journal of Materials Science: Materials in Electronics",
"year": 2016
},
{
"abstract": "Abstract Hydroxyapatite is the main inorganic component of bones and teeth. It has been extensively used as an implant material for bone substitute owing to its excellent biocompatible properties. Hydroxyapatite based composite materials shows significant properties in the field of biomedical applications. In our present work, Hydroxyapatite was synthesized via wet chemical precipitation reaction. Then four types of Hydroxyapatite based composites with 7.5 wt% each of Zinc oxide (ZnO) Titanium dioxide (TiO2) Ferric oxide (Fe2O3) and Ceria (Ce2O) via conventional sintering. The density of these composite materials was measured experimentally by Archimedes principle and compared with the theoretical density. The porosity of each composite material is calculated. X ray diffraction (XRD) analysis was carried out to identify different phase. Scanning Electron Microscope (SEM) analysis confirms the porosity. Energy dispersive spectroscopy was used to determine the ratio of different elements. The hardness of the composite materials was evaluated using Vickers' hardness tester. The compressive strength was evaluated using Compression test. It was observed that hardness and compressive strength of composite material increased with the addition of Fe2O3, ZnO, CeO2 and TiO2. However, the maximum value of hardness and compressive strength increased with the addition of Fe2O3 and were found to be 7.4 GPa and 406.3 MPa respectively. SEM micrographs clearly exhibit least porosity in HAP Fe2O3 samples which contributes to enhancement of mechanical properties.",
"author_names": [
"Ranveer Singh Soni",
"Vinay Pratap Singh"
],
"corpus_id": 229400787,
"doc_id": "229400787",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Fabrication and experimental analysis of hydroxyapatite based composite materials for medical implants",
"venue": "",
"year": 2020
},
{
"abstract": "Objective: The microbial, physico chemical and optical corruptions threaten a variety of foods and drugs and consequently the human biological safety and its accessible resources. The humanbeing's tendency towards bio based materials and natural plant extracts led to an increase in the usage of antimicrobial biocomposites based on medicinal herbs. Miswak (Salvadora persica L. extract (SPE) has been proved effective for its antimicrobial and other biological activities. Therefore, in this study, titanium dioxide (TiO2) nanoparticles (TONP) and SPE were applied to fabricate antimicrobial carboxymethyl cellulose (Na CMC) based bio nanocomposites which would simultaneously promote some thermo physical and barrier properties. Methods: CMC neat film (C1) CMC/TONP 2% (C2) and CMC/TONP 2% with 150, 300 and 450 mg/mL SPE (SPE150, SPE30 and SPE450, respectively) were fabricated. The physical and mechanical properties; elemental mapping analysis (MAP) X ray diffraction (XRD) scanning electron microscopy (SEM) thermal gravimetric analysis (TGA DTG) fourier transform infrared (FTIR) energy dispersive X ray (EDX) and UV vis spectroscopies were done to further validate the results. Results: Addition of TONP (2% improved the blocking of UV light at 280 nm while SPE containing nanocomposites completely blocked it. FTIR, XRD and SEM confirmed the formation of homogeneous films and high miscibility of applied materials. TONP led to an increase in Young's modulus (YM) and stress at break (SB) while SPE decreased them and enhanced the elongation to break (EB) (flexibility) of the active nanocomposites. Compared to CMC film, the thermo gravimetric analysis (TGA DTG) showed a higher thermal stability for CMC/TONP and CMC/TONP/SPE nanocomposites. The EDX spectroscopy and elemental mapping analysis (MAP) proved the existence and well distributedness of Na, K, Cl, S, Ti, F and N elements in SPE activated nanocomposites. The pure SPE and SPE activated nanocomposites showed a favorable antimicrobial activity against both gram positive (Staphylococcus aureus) and negative (Escherichia coli) bacteria. Conclusion: The CMC TiO2 SPE nanocomposites were homogeneously produced. Combination of TiO2 nanoparticles and dose dependent SPE led to an improvement of thermal stability, and high potential in antimicrobial and UV barrier properties. These results can generally highlight the role of the fabricated antimicrobial bio nanocomposites as a based for different applications especially in food/drug packaging or coating.",
"author_names": [
"Raman Ahmadi",
"Asghar Tanomand",
"Fahimeh Kazeminava",
"Fadhil S Kamounah",
"Ali Ayaseh",
"Khudaverdi Ganbarov",
"Mehdi Yousefi",
"Adib Katourani",
"Bahman Yousefi",
"Hossein Samadi kafil"
],
"corpus_id": 164499991,
"doc_id": "164499991",
"n_citations": 15,
"n_key_citations": 0,
"score": 0,
"title": "Fabrication and characterization of a titanium dioxide (TiO2) nanoparticles reinforced bio nanocomposite containing Miswak (Salvadora persica L. extract the antimicrobial, thermo physical and barrier properties",
"venue": "International journal of nanomedicine",
"year": 2019
},
{
"abstract": "The removal of heavy metal ions and organic materials from wastewater due to their toxicity is necessary. In the present study, the titanium dioxide/zinc oxide (TiO2 /ZnO) nanocomposite has been coated on the sewage sludge carbon (SSC) surface and its application was investigated for the adsorption of Ni(II) Cu(II) and chemical oxygen demands (COD) reduction from aqueous solutions and industrial wastewaters in Eshtehard, Iran. The effect of adsorption parameters in a single system such as TiO2 /ZnO ratio, TiO2 /ZnO concentration, pH, adsorbent dosage, contact time, ionic strength, temperature, and initial concentrations of Ni(II) Cu(II) and COD was investigated on the adsorption capacity of synthesized SSC/TiO2 /ZnO adsorbent. The pseudo second order and Redlich Peterson isotherm models were best described the kinetic and equilibrium data of Ni(II) Cu(II) and COD sorption. The maximum monolayer sorption capacities of Ni(II) Cu(II) and COD were found to be 62.3, 75.1, and 1,120.3 mg/g, respectively. The central composite design was used to investigate the interaction effects of pH and initial concentrations of Ni(II) Cu(II) and COD on the simultaneous removal of Ni(II) Cu(II) and COD from aqueous solutions in a ternary system. The potential of synthesized SSC/TiO2 /ZnO adsorbent was investigated for Ni(II) Cu(II) and COD adsorption from industrial wastewaters of Iran. PRACTITIONER POINTS: The novel sewage sludge carbon/TiO2 /ZnO adsorbent was synthesized. Adsorption of Ni(II) Cu(II) and chemical oxygen demands (COD) from industrial wastewaters was investigated. Maximum Ni(II) Cu(II) and COD sorption capacities were 62.3, 75.1, and 1,120.3 mg/g. Simultaneous removal of Ni(II) Cu(II) and COD was investigated in a ternary system.",
"author_names": [
"Mina Khosravi",
"Naser Mehrdadi",
"Gholam Reza Nabi Bidhendi",
"Majid Baghdadi"
],
"corpus_id": 207946279,
"doc_id": "207946279",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Synthesis of sewage sludge based carbon/TiO2 /ZnO nanocomposite adsorbent for the removal of Ni(II) Cu(II) and chemical oxygen demands from aqueous solutions and industrial wastewater.",
"venue": "Water environment research a research publication of the Water Environment Federation",
"year": 2019
},
{
"abstract": "Abstract ZnO nanomaterials with the stereochemical structure were becoming a research focus in the scope of photocatalytic materials, but the ZnO was sensitive to UV light rather than the solar light source, which considerably prohibited its extended application. ZnO nanomaterials coupled with other nanomaterials could generate the alternative composite heterojunction nanomaterials to promote the photocatalytic activity. Herein, we reported two facile and feasible synthesis methods to fabricate TiO2/ZnO cube nanocomposites and Ag/ZnO hollow spheres by hydrothermal reaction and chemical deposition, respectively. In this regard, these composited nanomaterials have been successfully fabricated with high purities, good morphology, and crystal structure. Noticeably, in contrast with TiO2/ZnO and Ag/ZnO bulk nanocomposites, the Ag/ZnO hollow spheres could offer the higher activity for RhB degradation under the visible light. Moreover, the photocatalytic performance of Ag/ZnO for RhB degradation could be improved synergistically, and the effect of RhB degradation was highest when the Ag mass ratio was modulated at 10% in the sample. Furthermore, it remained a high photocatalytic efficiency even after four cycles. This protocol provided an approvable approach to fabricate efficient photocatalysts with persistent photostability in the wastewater treatment process. Graphical abstract",
"author_names": [
"Yunfeng Liu"
],
"corpus_id": 238241732,
"doc_id": "238241732",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Fabrication of Ag/ZnO hollow nanospheres and cubic TiO2/ZnO heterojunction photocatalysts for RhB degradation",
"venue": "",
"year": 2021
},
{
"abstract": "Abstract Recent developments in nanocomposites have attracted the interest of researchers in synthesizing nanocomposite based photoluminescent materials. Lanthanides have been studied extensively as photoluminescent materials especially the Europium, owing to their simple energy level diagram, long luminescence lifetime, high emission quantum yield, and narrow emission bands in the visible region. The major limitation of using Europium for its practical application as a luminescent material is its low absorption coefficient that prevents the direct excitation of the Eu3+ ions. To improve the absorption, Europium has been doped with Y2O3 due to its similar energy level scheme i.e. 5D2 and 5L6. In our work, we have prepared Europium doped Y2O3:TiO2 nanocomposite and investigated its structural, morphological, and optical properties using characterization tools such as X ray Diffraction (XRD) Scanning electron microscopy (SEM) High resolution transmission electron spectroscopy (HRTEM) Fourier transform infrared spectroscopy (FTIR) Energy dispersive X ray spectroscopy (EDS) Elemental mapping, UV vis IR, and Photoluminescence (PL) spectroscopy. The material showed good optical properties and its application as a thermographic phosphor is studied via coating a NUV LED and observing the change in intensity with varying temperature under UV irradiation. The material can be used as a thermographic phosphor and even for the LED fabrication.",
"author_names": [
"Aamir Ahmed",
"Anoop Singh",
"Asha Sharma",
"",
"Sonali Verma",
"Sarika Mahajan",
"Sandeep Arya"
],
"corpus_id": 235534649,
"doc_id": "235534649",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Investigating the thermographical effect on optical properties of Eu doped Y2O3:TiO2 nanocomposite synthesized via sol gel method",
"venue": "",
"year": 2021
}
] |
Spintronics: A Spin-Based Electronics Vision for the Future | [
{
"abstract": "This review describes a new paradigm of electronics based on the spin degree of freedom of the electron. Either adding the spin degree of freedom to conventional charge based electronic devices or using the spin alone has the potential advantages of nonvolatility, increased data processing speed, decreased electric power consumption, and increased integration densities compared with conventional semiconductor devices. To successfully incorporate spins into existing semiconductor technology, one has to resolve technical issues such as efficient injection, transport, control and manipulation, and detection of spin polarization as well as spin polarized currents. Recent advances in new materials engineering hold the promise of realizing spintronic devices in the near future. We review the current state of the spin based devices, efforts in new materials fabrication, issues in spin transport, and optical spin manipulation.",
"author_names": [
"Stuart A Wolf",
"David D Awschalom",
"Robert A Buhrman",
"J M Daughton",
"Stephan von Molnar",
"Michael L Roukes",
"Almadena Yu Chtchelkanova",
"Daryl M Treger"
],
"corpus_id": 14010432,
"doc_id": "14010432",
"n_citations": 8448,
"n_key_citations": 39,
"score": 1,
"title": "Spintronics: A Spin Based Electronics Vision for the Future",
"venue": "Science",
"year": 2001
},
{
"abstract": "Conventional electronic devices based on the transport of electrical charge carriers electronsin a semiconductor such as silicon. Spintronics is an emerging field of electronics, where instead of using the charge of electrons, devices work by manipulating electron spin. In this paper describe a new paradigm of electronics based on the spin degree of freedom of the electron. Either adding the spin degree of freedom to conventional electronic devices or using the spin alone has the potential advantages of non volatility increased fast speed of data processing decreased electric power consumption, more versatile and increased integration densities compared with conventional semiconductor devices also used in Semiconductor lasers and nanotechnology. Recent research in new materials engineering hold the promise of realizing spintronic devices in near",
"author_names": [
"Vijay Laxmi Kalyani",
"Vaishali Agrawal"
],
"corpus_id": 201676869,
"doc_id": "201676869",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Spintronics A Vision for Future in Electronics and Computers",
"venue": "",
"year": 2015
},
{
"abstract": "In very near future human blood will be streaming with tiny nanorobots to get exact information about the infected cells or as intelligent drug delivery system and transmit the information to wireless cloud. Accordingly, low power and low dimensional electronics technology needs to be incorporated in a single agenda to show the path for development of these types of robots. Hence, the idea is to build low power, low dimensional nano robotic system which can be achieved by new generation ULSI hardware implementation. As an attempt towards this, here we present a straintronics based nano robotic system and its ULSI architecture. Straintronics or strain based spin electronics is an emerging field of IC fabrication technology for modern and future electronics. In straintronics data manipulate, control and store with spin degree of freedom. Electron spin instead of electron charge carries information in these devices. Hence, it requires very low power to operate and also the device can generate its own power from any stress upon it. This aspect offers opportunities for development of new generation of nano robotic devices with spin based electronics.",
"author_names": [
"Sampreet Sarkar",
"Syed Intekhab Alam",
"Varun Ravindran",
"Arpan Banerjee",
"Arghya Debnath",
"Ankush Ghosh"
],
"corpus_id": 90263626,
"doc_id": "90263626",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Spintronics based Systems for AI Nano Robots",
"venue": "2018 International Conference on Computing, Power and Communication Technologies (GUCON)",
"year": 2018
},
{
"abstract": "Metals recovery from electronic product recycling is currently focused on high value precious metals high volume metals that are easily recoverable. Current and future electronics will increasingly contain small quantities of resources which are not currently recovered in today's recycling infrastructure. Trends toward miniaturization, product dematerialization, and increasing materials heterogeneity create increasing challenges with respect to materials recovery, and the financial viability of electronics recycling generally. This situation is bad and getting worse. iNEMI (the International Electronics Manufacturing Initiative) undertook a project, the first phase of which was to examine the role its members could play in increasing metals recovery, while promoting sustainable electronics. In the second phase the project narrowed its focus to specifically address hard disk drives (HDDs) but expanded its focus to include all dimensions of the end of use system (EoU) that impact its financial viability. This included the reuse of HDDs, always the superior option, as well as the reclamation of critical raw materials being lost under the existing recycling paradigm. The report from this second project phase includes, a comprehensive assessment of the annual sales and trends for HDDs, a projection of the quantity of used HDDs available for enhanced value recovery through a stocks and flows analysis using system dynamics, a detailed characterisation of the decision trees employed by HDD EoU processors which determine whether a drive is reused (either directly, white labelled or for parts) or recycled (largely based on shredding) and the parameters that guide these decisions, an overview of data security and data destruction methods employed, an investigation of new pathways to value recovery including automated disassembly, removal and repurposing of magnets, and an industry wide survey examining the barriers and potential solutions to implementing these pathways. The project further examined whether conditions exist, as a way to implement these improvements, to develop a voluntary, community based solution involving adaptive governance systems to self manage common pool resources. This concept was inspired by the work of Dr. Eleanor Ostrom (2009 Nobel Laureate in Economics) It was concluded that the key necessary conditions do exist. Specifically: the system dynamics are sufficiently predictable, the number of users are known, the leadership exists The electronics industry is well organized by industry associations and certain large companies are recognized as leaders, the users of the resources share experience in group processes The industry has worked well together on many initiatives, e.g. RoHS transition, iNEMI, EICC, IEC EPEAT standards, and there exists a recognition of the importance of critical resources and supply risks. In summary the iNEMI study has defined a basis for action to address the disastrous economic situation for EoU electronics by maximizing value recovery opportunities. There are two directions that should be pursued from here: implement the opportunities for HDD value recovery, and conduct comparable analyses for other EoU components and products",
"author_names": [
"Wayne Rifer",
"Carol A Handwerker",
"William Olson",
"Colin Fitzpatrick",
"Willie Cade",
"Haley Fu"
],
"corpus_id": 117653693,
"doc_id": "117653693",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "A Vision for the Circular Economy in Hard Disk Drives Based on Self Management of Common Pool Resources",
"venue": "",
"year": 2017
},
{
"abstract": "Abstract Mass Customization (MC) has become a major trend in the consumer goods market in recent years. While the economic chances and threats are already described very well, the social and environmental impact of MC products remain unclear. Phonebloks, a design study of a modular smartphone launched in 2013, created a vision about fostering sustainability through MC. Teaming up with Google's Project Ara, a modular and customizable smartphone approach seemed very likely to reach market maturity. In 2016, Google canceled Project Ara shortly before the awaited market introduction. Analyzing the rise and fall of the first large scale MC based business model that was initially designed to foster sustainability in the consumer electronics market, gives us the opportunity to revise the economic, social and ecologic potential of modular and customizable smartphones in general. Furthermore, with constantly growing consumer requirements for new product iterations in shorter time frames, traditional measures for success, such as time to market, could change inherently as we are moving closer towards iterative product development processes and much shorter product life cycles. This, in turn, leads to major changes for ramp up processes. Using a qualitative case study approach based on expert interviews at two different stages of the Project Ara development process (2015 and 2017) we shed light on the future of modular and customizable smartphones and their economic, social and ecologic sustainability potential. We show that while Project Ara failed in the end, it had the economic potential to outperform its competitors in the field of modular smartphones. We find that an MC approach could lead to longer smartphone or, at least, component life cycles. Finally, we affirm a positive potential for influencing sociocultural behavior in the long tail of the smartphone market.",
"author_names": [
"Stephan Hankammer",
"Ruth Jiang",
"Robin Kleer",
"Martin Schymanietz"
],
"corpus_id": 85454044,
"doc_id": "85454044",
"n_citations": 13,
"n_key_citations": 0,
"score": 0,
"title": "Are modular and customizable smartphones the future, or doomed to fail? A case study on the introduction of sustainable consumer electronics",
"venue": "",
"year": 2017
},
{
"abstract": "Spin logic devices, due to their programmability and nonvolatility, are deemed as an ideal building block for the next generation of electronics. Though several types of spin logic based on domain wall motion, spin field effect transistor and automata made of magnetic nanoparticles have been proposed, an architecture with scalability, energy efficiency and compatibility with current complementary metal oxide semiconductor technology is still in urgent demand. Here, it is experimentally demonstrated that the spin Hall effect in magnetic films with perpendicular anisotropy can be utilized to construct such a spin logic device. Five commonly used logic gates with nonvolatility in a single device are realized. This demonstration could pave the way towards application of spintronics in logic circuits as well as the memory industry in the near future and could even give birth to logic in memory computing architectures.",
"author_names": [
"Caihua Wan",
"Xuan-tong Zhang",
"Z H Yuan",
"Chi Fang",
"Wenjie Kong",
"Qintong Zhang",
"Hao Wu",
"Usman Khan",
"Xiufeng Han"
],
"corpus_id": 49529412,
"doc_id": "49529412",
"n_citations": 44,
"n_key_citations": 1,
"score": 0,
"title": "Programmable Spin Logic Based on Spin Hall Effect in a Single Device",
"venue": "",
"year": 2017
},
{
"abstract": "Room temperature spin based electronics is the vision of spintronics. Presently, there are few suitable material systems. Herein, we reveal that solution processed mixed phase Ruddlesden Popper perovskite thin films transcend the challenges of phonon momentum scattering that limits spin transfer in conventional semiconductors. This highly disordered system exhibits a remarkable efficient ultrafast funneling of photoexcited spin polarized excitons from two dimensional (2D) to three dimensional (3D) phases at room temperature. We attribute this efficient exciton relaxation pathway towards the lower energy states to originate from the quantum coupling between intermediate states. This process bypasses the omnipresent phonon momentum scattering in typical semiconductors with stringent band dispersion, which causes the loss of spin information during thermalization. Film engineering using graded 2D/3D perovskites allows uni directional out of plane spin funneling over a thickness of ~600 nm. Our findings reveal an intriguing family of solution processed perovskites with extraordinary spin preserving energy transport properties that could reinvigorate the concepts of spin information transport.",
"author_names": [
"David Giovanni",
"Jia Wei Melvin Lim",
"Zhongcheng Yuan",
"Swee Sien Lim",
"Marcello Righetto",
"Jian Qing",
"Qiannan Zhang",
"Herlina Arianita Dewi",
"Feng Gao",
"Subodh Gautam Mhaisalkar",
"Nripan Mathews",
"Tze Chien Sum"
],
"corpus_id": 201316221,
"doc_id": "201316221",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Replication Data For: Ultrafast long range spin funneling in solution processed Ruddlesden Popper halide perovskites",
"venue": "",
"year": 2019
},
{
"abstract": "Room temperature spin based electronics is the vision of spintronics. Presently, there are few suitable material systems. Herein, we reveal that solution processed mixed phase Ruddlesden Popper perovskite thin films transcend the challenges of phonon momentum scattering that limits spin transfer in conventional semiconductors. This highly disordered system exhibits a remarkable efficient ultrafast funneling of photoexcited spin polarized excitons from two dimensional (2D) to three dimensional (3D) phases at room temperature. We attribute this efficient exciton relaxation pathway towards the lower energy states to originate from the energy transfer mediated by intermediate states. This process bypasses the omnipresent phonon momentum scattering in typical semiconductors with stringent band dispersion, which causes the loss of spin information during thermalization. Film engineering using graded 2D/3D perovskites allows unidirectional out of plane spin funneling over a thickness of ~600 nm. Our findings reveal an intriguing family of solution processed perovskites with extraordinary spin preserving energy transport properties that could reinvigorate the concepts of spin information transfer. Spin information transport or transfer is essential for spintronics applications and often relies on high purity and quality materials. Here, the authors report on the defect tolerant solution processed Ruddlesden Popper halide perovskites, where a spin propagation length of 600 nm was achieved via spin funneling.",
"author_names": [
"David Giovanni",
"Jia Wei Melvin Lim",
"Zhongcheng Yuan",
"Swee Sien Lim",
"Marcello Righetto",
"Jian Qing",
"Qiannan Zhang",
"Herlina Arianita Dewi",
"Feng Gao",
"Subodh Gautam Mhaisalkar",
"Nripan Mathews",
"Tze Chien Sum"
],
"corpus_id": 199379244,
"doc_id": "199379244",
"n_citations": 16,
"n_key_citations": 1,
"score": 0,
"title": "Ultrafast long range spin funneling in solution processed Ruddlesden Popper halide perovskites",
"venue": "Nature Communications",
"year": 2019
},
{
"abstract": "Today's world is driven by digital computing and information technology, which has been made possible by the mass production of integrated circuits with faster and smaller transistors. Since the last five decades, the semiconductor industry has been successful in doubling the processing power of a computer chip every 2 years. This has been achieved by making tinier transistors and packing more of them in the same chip. Presently, the transistor sizes are in the order of a few nanometres, approaching the size of atoms (a million times smaller than the diameter of a human hair) However, as the transistor size is reduced further, its performance is adversely affected due to quantum mechanical effects. This has led to the development of alternative technologies for future device applications. This thesis is about one such alternative technology, which utilizes a fundamental property of the electron, known as 'spin' instead of the electronic charge. Spintronics, or spin based electronics, can be utilized to make cheaper, faster and energy efficient devices. The three main challenges in spintronics are the efficient generation, manipulation and detection of spin currents. The experiments presented in this thesis attempt to provide innovative solutions and investigate new ways of tackling these main challenges. Spin transport in a non local geometry is the primary tool that has been used for this research. The experimental chapters investigate different techniques through which spins can be efficiently controlled, viz. spin orbit interaction, heat, curved geometry and magnons. These results have direct implications for spin based memory and logic devices.",
"author_names": [
"Kumar Sourav Das"
],
"corpus_id": 182837920,
"doc_id": "182837920",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Controlling spins in nanodevices via spin orbit interaction, magnons and heat",
"venue": "",
"year": 2019
},
{
"abstract": "Electron spins are envisioned to play a key role in future information technologies. Apart from complementing charge based functionalities, spin based electronics (spintronics) offers entirely new possibilities. They emerge particularly from spintronic effects allowing for the mutual conversion of charge (or heat) and spin currents. Consequently, widespread applications already exist, including the magnetic random access memory, which became commercially available only recently. On the other hand, field effect transistors reaching cut off frequencies of up to 1THz have been demonstrated. This strongly suggests that future spintronic devices eventually need to operate at terahertz (THz) speeds. Consequently, the following questions will be studied in this thesis: Are central spintronic effects operative up to highest THz frequencies? What are the initial elementary processes in their formation? How can we exploit new functionalities? Thereby, intriguing, new phenomena may be found since many fundamental excitations in solids resonate with THz radiation. Most importantly, the spin orbit interaction, one of the cornerstones of spintronics, typically falls into the THz energy range. Apart from these exciting fundamental motivations, innovative spintronic concepts might advance other application fields, in particular THz photonics. In this work, we first demonstrate the anomalous Hall effect at highest THz frequencies in technologically relevant metals. Remarkably, we find an anomalous Hall angle ~2% nearly constant from 1 40 THz. This result is understood in terms of the largely disordered materials, strongly blurring any spectral features. Second, we exploit spintronic effects at THz frequencies to build an efficient and ultrabroadband THz spintronic emitter, based on nanometer thin magnetic and strongly spin orbit coupled metals. It relies on ultrashort photoexcitation and the combination of the ultrafast spin dependent Seebeck effect with the inverse spin Hall effect, and outperforms standard emitters in terms of bandwidth, ease of use, low cost, and scalability. By upscaling, we develop a THz spintronic high field source allowing for nonlinear THz spectroscopy. Furthermore, we use THz emission spectroscopy to characterize spintronic materials all optically. Third, we aim at revealing the fundamental processes in the ultrafast conversion of heat gradients into spin currents. Therefore, we measure the spin Seebeck effect at THz frequencies in prototypical magnetic insulator/normal metal bilayers. We find an ultrafast rise time of ~100 fs, which is ascribed to carrier multiplication during the thermalization of the photo excited metal electrons. Our findings are relevant for all processes involving photo induced spin transfer. In conclusion, this work demonstrates the synergies released upon combining two vibrant fields of research: spintronics and THz spectroscopy.",
"author_names": [
"Tom S Seifert"
],
"corpus_id": 125931797,
"doc_id": "125931797",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Spintronics with Terahertz Radiation: Probing and driving spins at highest frequencies",
"venue": "",
"year": 2018
}
] |
Microwave synthesis of perovskites | [
{
"abstract": "Abstract Bismuth vanadate (BiVO4) is considered one of the most successful candidates to be used as photoanode for solar to hydrogen conversion. However, its relatively high recombination rates and considered low long term stability limits its applicability. Doping BiVO4 with tungsten and developing heterojunctions with inorganic perovskites has emerged as strategies to overcome these issues. However, the development of these materials requires plenty of time and energy. Here, we reported the development of a new synthetic method to prepare heterojunctions of tungsten doped bismuth vanadate (using 1, 3 and 5 in mass of W) and tungsten oxide. The heterojunctions were prepared in a one pot microwave assisted method that takes only 24 min. Photocatalytic efficiency was determined through quantification of the amount of hydroxyl radical, generated by the catalysts when they are irradiated with simulated sunlight, and through photoelectrochemical experiments. The heterojunctions showed enhanced photocatalytic activity, which was ascribed to the adequate alignment of the band edges potentials of the semiconductors. Also, the tungsten doping decreases the recombination rates. Both effects increase the photogenerated charges lifetime.",
"author_names": [
"Caroline H Claudino",
"Maria Kuznetsova",
"Barbara Scola Rodrigues",
"Changqiang Chen",
"Zhiyu Wang",
"M R Sardela",
"Juliana S Souza"
],
"corpus_id": 213940556,
"doc_id": "213940556",
"n_citations": 15,
"n_key_citations": 0,
"score": 1,
"title": "Facile one pot microwave assisted synthesis of tungsten doped BiVO4/WO3 heterojunctions with enhanced photocatalytic activity",
"venue": "",
"year": 2020
},
{
"abstract": "Abstract La2CuO4/LaFeO3 perovskite nanocomposites were prepared using a microwave combustion technique. The structural characterization by XRD and Rietveld refinements confirmed that Fe3+ substitution in La2CuO4 (LFC) induced the crystallization of secondary LaFeO3 phase. The orthorhombic/cubic nanostructured composites exhibited an average crystallite size in the range 37 47 nm and 14 39 nm, respectively. FTIR spectra revealed bands at 517, 683, and 561 cm 1, characteristics of perovskites orthorhombic and cubic stretching modes. With the increase in Fe3+ doping concentration, the optical band gap increased gradually. Surface morphology showed nanosized crystalline grains agglomerated with spherical and non spherical shapes. The doping dependence of the magnetisation indicated magnetic transition from ferromagnetic to the paramagnetic state at room temperature. The bifunctional nanocomposites La2CuO4/LaFeO3 exhibited excellent catalytic performance and better conversion efficiency (conversion 100% and selectivity 98.6% for glycerol.",
"author_names": [
"M Sukumar",
"Lourdusamy John Kennedy",
"J Judith Vijaya",
"B Al-Najar",
"Mohamed Bououdina"
],
"corpus_id": 182503663,
"doc_id": "182503663",
"n_citations": 9,
"n_key_citations": 0,
"score": 0,
"title": "Facile synthesis of Fe3+ doped La2CuO4/LaFeO3 perovskite nanocomposites: Structural, optical, magnetic and catalytic properties",
"venue": "Materials Science in Semiconductor Processing",
"year": 2019
},
{
"abstract": "Abstract A series of La0.7 xPrxCa0.3MnO3 (x 0.35, 0.52 or 0.63) perovskites were synthesized using microwave method at different reaction times (3, 4 and 5 min) as possible cathode material for solid oxide fuel cell (SOFCs) SOFCs are a forward looking technology for a highly efficient, environmental friendly power generation. Variation of lattice parameters, unit cell volume and final composition with Pr concentration were analyzed by Rietveld refinement and X ray photo electron spectroscopy (XPS) Thereafter, samples were sintered (at 1000 degC) to evaluate their electrical properties at room temperature. Rietveld refinement showed that all the samples were a single phase perovskite type and belongs to orthorhombic Pnma structure. The atomic composition of doped samples is close to theoretical stoichiometric values. XPS analysis revealed significant changes in the La 3d, Ca 2p, Mn 2p and O 1s intensities as a result of the Pr incorporation.",
"author_names": [
"A C Ferrel-Alvarez",
"Miguel A Dominguez-Crespo",
"Hongbo Cong",
"Aide Minerva Torres-Huerta",
"Silvia B Brachetti-Sibaja",
"W De La Cruz"
],
"corpus_id": 103083238,
"doc_id": "103083238",
"n_citations": 21,
"n_key_citations": 0,
"score": 0,
"title": "Synthesis and surface characterization of the La0.7 xPrxCa0.3MnO3 (LPCM) perovskite by a non conventional microwave irradiation method",
"venue": "",
"year": 2018
},
{
"abstract": "Low temperature routes have been developed for the preparation of BaCe0,85Y0,15O2,925 (BCY15) in the form of ethanol nanoparticles slurries for use in the central membrane of an original dual cell. Microwave synthesis leads to homogeneous nanoparticles crystalline precursor, as observed by HR TEM and selected diffraction area (SAD) Single phase yttrium doped barium cerate perovskites is obtained, as observed by X ray diffraction, after thermal treatment at 1200degC for 5h. Dynamic temperature X ray diffraction study revealed that BCY phase growth at 850degC. The BCY15 phase can be obtained after 4h at 950degC. This temperature, lower than those usually used for preparation of BCY, lead to small oxide nanoparticles.",
"author_names": [
"A Gallon",
"Didier Stuerga",
"Nicolas Geoffroy",
"Christoph Lohr"
],
"corpus_id": 201721994,
"doc_id": "201721994",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "New Microwave Synthesis of Yttrium Doped Barium Cerate Nanoparticles Precursor Phase Transformation During Sintering",
"venue": "",
"year": 2011
},
{
"abstract": "Abstract A study on the synthesis of La 1 x Ag x MnO 3+ d x 0, 0.2) using a microwave process (MWhyd) has been carried out by comparing the heating time and reaction temperature with the same factor under conventional thermal process (CHhyd) Experiments have been conducted using the hydrothermal method at medium pressure T 200 degC, P 20 atm) followed by a thermal treatment of the precursor at 700 degC (10 h) Structural and physico chemical properties of the catalysts were investigated using X ray diffraction (XRD) BET sorption, temperature programmed reduction or desorption, mass spectrometry (TPR MS and TPD MS) and X ray photoelectron spectroscopy (XPS) While CHhyd and MWhyd powder catalysts exhibited the same XRD patterns indexed as pure perovskite structure, their surface physico chemical properties were found to be strongly influenced by the preparation method. The effect of the nature of oxygen species, their amount and mobility, evidenced by temperature programmed experiments, on the catalytic properties in methane combustion in the presence and in the absence of hydrogen sulphide has been studied. MWhyd La 0.8 Ag 0.2 MnO 3+ d catalysts were found to exhibit a much better performance in methane combustion together with higher resistance to sulphur poisoning than CHhyd catalysts.",
"author_names": [
"Simon Ifrah",
"Akim Kaddouri",
"Patrick Gelin",
"Didier Leonard"
],
"corpus_id": 95722297,
"doc_id": "95722297",
"n_citations": 28,
"n_key_citations": 1,
"score": 0,
"title": "Conventional hydrothermal process versus microwave assisted hydrothermal synthesis of La1 xAgxMnO3+d (x 0, 0.2) perovskites used in methane combustion",
"venue": "",
"year": 2007
},
{
"abstract": "Abstract Hydrothermal microwave method (HTMW) was used to synthesize crystalline bismuth ferrite (BiFeO 3 nanoparticles (BFO) in the temperature of 180 degC with times ranging from 5 min to 1 h. BFO nanoparticles were characterized by means of X ray analyses, FT IR, Raman spectroscopy, TG DTA and FE SEM. X ray diffraction results indicated that longer soaking time was benefit to refraining the formation of any impurity phases and growing BFO crystallites into almost single phase perovskites. Typical FT IR spectra for BFO nanoparticles presented well defined bands, indicating a substantial short range order in the system. TG DTA analyses confirmed the presence of lattice OH groups, commonly found in materials obtained by HTMW process. Compared with the conventional solid state reaction process, submicron BFO crystallites with better homogeneity could be produced at the temperature as low as 180 degC. These results show that the HTMW synthesis route is rapid, cost effective, and could be used as an alternative to obtain BFO nanoparticles in the temperature of 180 degC for 1 h.",
"author_names": [
"Glenda Biasotto",
"Alexandre Zirpoli Simoes",
"Cesar Foschini",
"Maria Aparecida Zaghete",
"Jose Arana Varela",
"Elson Longo"
],
"corpus_id": 98269776,
"doc_id": "98269776",
"n_citations": 44,
"n_key_citations": 0,
"score": 1,
"title": "Microwave hydrothermal synthesis of perovskite bismuth ferrite nanoparticles",
"venue": "",
"year": 2011
},
{
"abstract": "Orthorhombic structure perovskite LaFeO3 nanocrystals are synthesized by three simple and effective routes using octanoic acid as organic surfactant, namely co precipitation, ultrasonic and microwave assisted co precipitation methods. The phase composition, morphology, lattice parameters and size of nanoparticles in these materials are characterized through Fourier transform infrared spectroscopy, X ray diffraction, scanning electron microscopy, and energy dispersive X ray spectrometer. Magnetic measurements are carried out by a vibrating sample magnetometer on the resultant powders at room temperature. The perovskites synthesized using three methods yield comparatively pure crystalline phase of LaFeO3. However, the particle shape and size ranging changes from short rod like nanoparticles in co precipitation method to sphere like nanoparticles in ultrasonic and microwave assisted co precipitation methods. In addition, the results show that the formation time is decreased considerably by ultrasonic or microwave irradiation.",
"author_names": [
"Mozhgan Khorasani-Motlagh",
"Meissam Noroozifar",
"Akram Ahanin-Jan"
],
"corpus_id": 95239562,
"doc_id": "95239562",
"n_citations": 16,
"n_key_citations": 0,
"score": 0,
"title": "Ultrasonic and microwave assisted co precipitation synthesis of pure phase LaFeO3 perovskite nanocrystals",
"venue": "Journal of the Iranian Chemical Society",
"year": 2012
},
{
"abstract": "Abstract The present investigation discusses the synthesis and dielectric properties of three series of oxides of the formula La 2 BaTi 2 M 1 x Cu x O 9 (where M Mg, Zn and Cd) The reactions have been carried out via solid state method and all the compositions crystallize in the disordered cubic perovskite structure. Suitable substitution at both A and B sites lead to enhancement in the dielectric properties at high frequencies. The relative permittivity and loss tangent have been measured at X band (8.2 12.4 GHz) and Ku band (12.4 18 GHz) frequencies. The oxides show a dielectric constant of 20 30 while the dielectric loss is quite low in the order of 10 3 10 4 (at 500 kHz) and 10 2 at X and Ku band. There is scope for further investigations in these systems to realize useful materials for microwave applications.",
"author_names": [
"Masood A Nath",
"Saroj L Samal",
"K Rama Obulesu",
"Kanakkappillavila Chinnayya James Raju",
"Ashok Kumar Ganguli"
],
"corpus_id": 137021394,
"doc_id": "137021394",
"n_citations": 10,
"n_key_citations": 0,
"score": 0,
"title": "Microwave dielectric properties of lanthanum based complex perovskites",
"venue": "",
"year": 2014
},
{
"abstract": "A new strategy for the functionalization of layered perovskites is presented, based on the in situ post synthesis modification of a prefunctionalized phase by copper(I) catalyzed alkyne azide cycloaddition (CuAAC) The microwave assisted protonation and grafting of an alkyne alcohol provides the alkyne functionalized precursor within a few hours, starting from Bi2SrTa2O9. The subsequent microwave assisted in situ \"click reaction\" allows the post synthesis modification of the precursor within ~2 h, providing a layered perovskite functionalized by an alcohol grafted 1,4 disubstituted 1H 1,2,3 triazole. Two compounds are described here, bearing an aliphatic and an aromatic substituent, which illustrates the general application of the method. This work opens new perspectives for the functionalization of layered perovskites, going beyond mere insertion/grafting reactions, and thus broadens the design possibilities and the range of applications of these hybrid systems.",
"author_names": [
"Yanhui Wang",
"Emilie Delahaye",
"C Leuvrey",
"Fabrice Leroux",
"Pierre Rabu",
"Guillaume Rogez"
],
"corpus_id": 30619311,
"doc_id": "30619311",
"n_citations": 9,
"n_key_citations": 0,
"score": 0,
"title": "Post Synthesis Modification of the Aurivillius Phase Bi2SrTa2O9 via In Situ Microwave Assisted \"Click Reaction\"",
"venue": "Inorganic chemistry",
"year": 2016
},
{
"abstract": "Low dimensional lead halide hybrid perovskites are nowadays in the spotlight because of their improved stability and extensive chemical flexibility compared to their 3D perovskite counterparts, the current challenge being to design functionalized organic cations. Here, we report on the synthesis and full characterization of a perovskite like hybrid (a perovskitoid) where the 1D lead iodide layout is patterned with a donor acceptor charge transfer complex (CTC) between pyrene and tetracyanoquinodimethane, with a chemical formula of (C20H17NH3)PbI3*(C12H4N4) By combining multiple structural analysis and spectroscopic techniques with ab initio modeling, we show that the electronic, optical, and charge transport properties of the hybrid materials are dominated by the organic CTC, with the inorganic backbone primarily acting as a template for the organization of the donor and acceptor molecules. Interestingly, time resolved microwave conductivity (TRMC) measurements show an enhanced photocurrent generation in.",
"author_names": [
"Nadege Marchal",
"Wouter T M Van Gompel",
"Maria C Gelvez-Rueda",
"Koen Vandewal",
"Kristof Van Hecke",
"Hans Gerd Boyen",
"Bert Conings",
"Roald Herckens",
"Sudeep Maheshwari",
"Laurence Lutsen",
"Claudio Quarti",
"Ferdinand C Grozema",
"Dirk Vanderzande",
"David Beljonne"
],
"corpus_id": 201231537,
"doc_id": "201231537",
"n_citations": 17,
"n_key_citations": 0,
"score": 0,
"title": "Lead Halide Perovskites Meet Donor Acceptor Charge Transfer Complexes",
"venue": "Chemistry of Materials",
"year": 2019
}
] |
EMBEDDED IMAGE ACQUISITION SYSTEM | [
{
"abstract": "Electro optical measurements, i.e. optical waveguides and plasmonic based electrochemical impedance spectroscopy (P EIS) are based on the sensitive dependence of refractive index of electro optical sensors on surface charge density, modulated by an AC electrical field applied to the sensor surface. Recently, P EIS has emerged as a new analytical tool that can resolve local impedance with high, optical spatial resolution, without using microelectrodes. This study describes a high speed image acquisition and processing system for electro optical measurements, based on a high speed complementary metal oxide semiconductor (CMOS) sensor and a field programmable gate array (FPGA) board. The FPGA is used to configure CMOS parameters, as well as to receive and locally process the acquired images by performing Fourier analysis for each pixel, deriving the real and imaginary parts of the Fourier coefficients for the AC field frequencies. An AC field generator, for single or multi sine signals, is synchronized with the high speed acquisition system for phase measurements. The system was successfully used for real time angle resolved electro plasmonic measurements from 30 Hz up to 10 kHz, providing results consistent to ones obtained by a conventional electrical impedance approach. The system was able to detect amplitude variations with a relative variation of 1% even for rather low sampling rates per period (i.e. 8 samples per period) The PC (personal computer) acquisition and control software allows synchronized acquisition for multiple FPGA boards, making it also suitable for simultaneous angle resolved P EIS imaging.",
"author_names": [
"Mihnea Rosu-Hamzescu",
"Cristina Polonschii",
"Sergiu Oprea",
"Dragos Popescu",
"Sorin David",
"Dumitru Bratu",
"Eugen Gheorghiu"
],
"corpus_id": 49650356,
"doc_id": "49650356",
"n_citations": 4,
"n_key_citations": 0,
"score": 1,
"title": "High speed CMOS acquisition system based on FPGA embedded image processing for electro optical measurements.",
"venue": "The Review of scientific instruments",
"year": 2018
},
{
"abstract": "Embedded eye tracking systems usually require high performance of the physical devices on which they are implemented. Low power consumption, low heat and small size factors create barriers in decision making to define the core components of the final design of such a system. For the proposed system, a custom board was manufactured to meet these requirements. The board uses an ARM Cortex A9 based microcontroller, FPGA and two external RAM memory integrated circuits. However, in order to ensure maximal efficiency in terms of utilization of each hardware component, proper software modules should be designed. In this paper we are presenting an image acquisition architecture for eye tracking systems and discuss its performance.",
"author_names": [
"Pavel Morozkin",
"Marc Swynghedauw",
"Maria Trocan"
],
"corpus_id": 6004457,
"doc_id": "6004457",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Design of an embedded image acquisition system",
"venue": "2015 IEEE International Conference on Electronics, Circuits, and Systems (ICECS)",
"year": 2015
},
{
"abstract": "Based on the requirements of miniaturization, stability and definition of the image acquisition device, an embedded Linux image acquisition and display system based on embedded system is designed. The system hardware using ARM core S3C2440 microprocessor, USB camera and LCD display to build image acquisition and display system; the software system placed Linux system as the core is built. Build hardware platform and transplant Linux operating system and related drivers, to achieve the image acquisition and display system miniaturization and stability and image quality have reached the people's requirements.",
"author_names": [
"Hong He",
"Yang Li",
"Zhihong Zhang"
],
"corpus_id": 23652082,
"doc_id": "23652082",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Design of image acquisition system based on embedded Linux",
"venue": "2017 29th Chinese Control And Decision Conference (CCDC)",
"year": 2017
},
{
"abstract": "The paper analyzes the development status at home and abroad of the embedded system, the embedded application in view of the current, this paper introduces a ARM embedded image acquisition and transmission scheme based on. The program takes advantage of the powerful function of WINCE, with small size, high stability and rapid development, has completed the hardware design and software development, the basic system stability, good safety.",
"author_names": [
"Cheng Xiny"
],
"corpus_id": 115065951,
"doc_id": "115065951",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "The Design of Embedded Image Acquisition and Transmission System",
"venue": "",
"year": 2015
},
{
"abstract": "An image acquisition system is designed based on STM32 embedded system and OV2640 camera with 200 million pixels.The basic hardware structure is analyzed,and the features of different modules are introduced briefly.Meanwhile,the software design is explained in detail.The basic process of the system initialization and the use of associated peripheral modules in the program are given.At last,the overall idea of system is introduced,and it achieves the stable operation of the system.",
"author_names": [
"Tianhuang Industrial"
],
"corpus_id": 62947502,
"doc_id": "62947502",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Embedded Image Acquisition System Design Based on STM32 and OV2640",
"venue": "",
"year": 2014
},
{
"abstract": "For fairly solving the problem of security monitoring,lowering the cost and improving the stability of image qcuisition,this paper describes a design of image acquisition based on ARM9 S3C2440 processor,gives the concrete realization of image acquisition,and discusses the software and hardware design of embedded image acquisition.The experiment result indicates that this system is stable and reliable,and the design scheme is feasible and effective.",
"author_names": [
"Li Peng-fei"
],
"corpus_id": 63062451,
"doc_id": "63062451",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Design and Implementation of Embedded Image Acquisition System",
"venue": "",
"year": 2013
},
{
"abstract": "To obtain a wider view around underwater robotic vehicle, a remote underwater dual cameras acquisition system based on V4L2 is developed. Athena III PC104 with embedded Linux uses two USB cameras for the hardware development platform. After transplanting the embedded Linux OS and drivers, the image acquisition combined with V4L2 using the X264 and FFMPEG is implemented for digital image encoding and decoding. The images are transported into two separate image channels to network via User Datagram Protocol (UDP) socket. A graphical user interface is designed using GTK toolkit for user display purpose. Experimental tests had shown that the two channel image data were able to transmit independently without much interference and data loss. In addition, the image size of 320x240 transmitting at a frame rate of 10 frames per second had shown a good quality video. The proposed acquisition system has a good scalability and offers a new approach for embedded system design for remote multi channel signal acquisition in underwater.",
"author_names": [
"W P Lin",
"Cheng Siong Chin"
],
"corpus_id": 40416594,
"doc_id": "40416594",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Remote underwater dual cameras video image acquisition system using Linux based embedded PC104",
"venue": "OCEANS 2014 TAIPEI",
"year": 2014
},
{
"abstract": "",
"author_names": [
"Hong Su"
],
"corpus_id": 61888998,
"doc_id": "61888998",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "The Embedded Image Acquisition System Based on the ARM",
"venue": "",
"year": 2013
},
{
"abstract": "This article is based on CMOS image sensor which is commonly used in image acquisition. It applies 32 bit ARM9 microprocessor S3C2410A as the CPU to control other function modules and designs embedded Arm9 image acquisition system for the realization of machine vision. The main function modules are SDRAM memory cell, image acquisition unit and Ethernet transmission module, UART serial port communication module, Flash module, power supply module, etc. Compared with machine vision systems of the traditional \"image acquisition card PC terminal control device\" model, the image acquisition system has advantages of small volume, low cost, low power consumption, strong real time performance, etc. And it can be used for practical application in video image monitoring, automatic detection, medical and military detection and so on. In a word, it has a good application prospect. Copyright (c) 2013 IFSA.",
"author_names": [
"Niqin Jing",
"Yu Wang"
],
"corpus_id": 16356147,
"doc_id": "16356147",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Embedded ARM 9 Image Acquisition System Based on CMOS Image Sensor",
"venue": "",
"year": 2014
},
{
"abstract": "An embedded image acquisition and transmission scheme based on WinCE is introduced,and the basic hardware design and software development are completed.The hardware used USB camera and S3C2440 processor to constitute embedded image acquisition device and connect the host through an Ethernet.The software included system software transplant and application software development.The system software included BOOTLOADER of ARM platform,WinCE system transplant and camera drive development.The application software included the design of image acquisition module and the design of image transmission module.The system has advantages of small volume,high stability and rapid development.",
"author_names": [
"Yuan Zu-long"
],
"corpus_id": 63967957,
"doc_id": "63967957",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Design of Embedded Image Acquisition System Based on WinCE",
"venue": "",
"year": 2011
}
] |
Handbook of Optical Constants of Solids, | [
{
"abstract": "VOLUME ONE: Determination of Optical Constants: E.D. Palik, Introductory Remarks. R.F. Potter, Basic Parameters for Measuring Optical Properties. D.Y. Smith, Dispersion Theory, Sum Rules, and Their Application to the Analysis of Optical Data. W.R. Hunter, Measurement of Optical Constants in the Vacuum Ultraviolet Spectral Region. D.E. Aspnes, The Accurate Determination of Optical Properties by Ellipsometry. J. Shamir, Interferometric Methods for the Determination of Thin Film Parameters. P.A. Temple, Thin Film Absorplance Measurements Using Laser Colorimetry. G.J. Simonis, Complex Index of Refraction Measurements of Near Millimeter Wavelengths. B. Jensen, The Quantum Extension of the Drude Zener Theory in Polar Semiconductors. D.W. Lynch, Interband Absorption Mechanisms and Interpretation. S.S. Mitra, Optical Properties of Nonmetallic Solids for Photon Energies below the Fundamental Band Gap. Critiques Metals: D.W. Lynch and W.R. Hunter, Comments of the Optical Constants of Metals and an Introduction to the Data for Several Metals. D.Y. Smith, E. Shiles, and M. Inokuti, The Optical Properties of Metallic Aluminum. Critiques Semiconductors: E.D. Palik, Cadium Telluride (CdTe) E.D. Palik, Gallium Arsenide (GaAs) A. Borghesi and G. Guizzetti, Gallium Phosphide (GaP) R.F. Potter, Germanium (Ge) E.D. Palik and R.T. Holm, Indium Arsenide (InAs) R.T. Holm, Indium Antimonide (InSb) O.J. Glembocki and H. Piller, Indium Phosphide (InP) G. Bauer and H. Krenn, Lead Selenide (PbSe) G. Guizzetti and A. Borghesi, Lead Sulfide (PbS) G. Bauer and H. Krenn, Lead Telluride (PbTe) D.F. Edwards, Silicon (Si) H. Piller, Silicon (Amorphous) Si) W.J. Choyke and E.D. Palik, Silicon Carbide (SiC) E.D. Palik and A. Addamiano, Zinc Sulfide (ZnS) Critiques Insulators: D.J. Treacy, Arsenic Selenide (As 2 gt Se 3 gt D.J. Treacy, Arsenic Sulfide (As 2 gt S 3 gt D.F. Edwards and H.R. Philipp, Cubic Carbon (Diamond) E.D. Palik and W.R. Hunter, Litium Fluoride (LiF) E.D. Palik, Lithium Niobote (LiNbO 3 gt E.D. Palik, Potassium Chloride (KCl) H.R. Philipp, Silicon Dioxide (SiO 2 gt Type (Crystalline) H.R. Philipp, Silicon Dioxide (SiO 2 gt (Glass) gt H.R. Philipp, Silicon Monoxide (SiO) (Noncrystalline) H.R. Philipp, Silicon Nitride (Si 3 gt N 4 gt (Noncrystalline) J.E. Eldridge and E.D. Palik, Sodium Chloride (NaCl) M.W. Ribarsky, Titanium Dioxide (TiO 2 gt (Rutile)",
"author_names": [
"Edward D Palik"
],
"corpus_id": 138765507,
"doc_id": "138765507",
"n_citations": 12904,
"n_key_citations": 539,
"score": 1,
"title": "Handbook of Optical Constants of Solids",
"venue": "",
"year": 1997
},
{
"abstract": "",
"author_names": [
"David W Lynch",
"William R Hunter"
],
"corpus_id": 135471795,
"doc_id": "135471795",
"n_citations": 4975,
"n_key_citations": 204,
"score": 0,
"title": "Handbook of Optical Constants of Solids",
"venue": "",
"year": 1985
},
{
"abstract": "",
"author_names": [
"Oliver S Heavens"
],
"corpus_id": 120965652,
"doc_id": "120965652",
"n_citations": 851,
"n_key_citations": 64,
"score": 0,
"title": "Handbook of Optical Constants of Solids II",
"venue": "",
"year": 1992
},
{
"abstract": "",
"author_names": [
"Edward D Palik",
"Gorachand Ghosh"
],
"corpus_id": 229871481,
"doc_id": "229871481",
"n_citations": 43,
"n_key_citations": 6,
"score": 0,
"title": "The electronic handbook of optical constants of solids",
"venue": "",
"year": 1999
},
{
"abstract": "We report on the performance of density functional theory (DFT) with the Tran Blaha modified Becke Johnson exchange potential and the random phase approximation dielectric function for optical constants of semiconductors in the ultraviolet visible (UV Vis) light region. We calculate optical bandgaps Eg, refractive indices n, and extinction coefficients k of 70 semiconductors listed in the Handbook of Optical Constants of Solids (Academic Press, 1985) Vol. 1; (Academic Press, 1991) Vol. 2; and (Academic Press, 1998) Vol. 3] and compare the results with experimental values. The results show that the calculated bandgaps and optical constants agree well with the experimental values to within 0.440 eV for Eg, 0.246 0.299 for n, and 0.207 0.598 for k in root mean squared error (RMSE) The small values of the RMSEs indicate that the optical constants of semiconductors in the UV Vis region can be quantitatively predicted even by a low cost DFT calculation of this type.",
"author_names": [
"Kousuke Nakano",
"Tomohiro Sakai"
],
"corpus_id": 103085988,
"doc_id": "103085988",
"n_citations": 13,
"n_key_citations": 0,
"score": 0,
"title": "Assessing the performance of the Tran Blaha modified Becke Johnson exchange potential for optical constants of semiconductors in the ultraviolet visible light region",
"venue": "",
"year": 2018
},
{
"abstract": "Lead sulfide (PbS) in thin film form was prepared by thermal evaporation in order to evaluate its optical characteristics. The absorption coefficient of lead sulfide in the 3 11 microns band of the infrared spectrum was calculated under smooth and rough surface conditions. The calculated and measured absorption coefficient was in a good agreement with that published by Semiletov. These results were an order of magnitude higher than that published in the handbook of optical constants of solids and referred to Scanlon.",
"author_names": [
"I Elfalla",
"Ahmed H Zaki",
"Shahriar Alian"
],
"corpus_id": 60491254,
"doc_id": "60491254",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Optical constants of lead sulfide in the 3 11 microns window",
"venue": "Proceedings of the Sixteenth National Radio Science Conference. NRSC'99 (IEEE Cat. No.99EX249)",
"year": 1999
},
{
"abstract": "Historical Figures in Chemistry and Physics Basic Constants, Units, and Conversion Factors Symbols, Terminology, and Nomenclature Physical Constants of Organic Compounds Properties of the Elements and Inorganic Compounds Thermochemistry, Electrochemistry, and Solution Chemistry Fluid Properties Biochemistry Analytical Chemistry Molecular Structure and Spectroscopy Atomic, Molecular, and Optical Physics Nuclear and Particle Physics Properties of Solids Polymer Properties Geophysics, Astronomy, and Acoustics Practical Laboratory Data Health and Safety Information APPENDICES: Mathematical Tables. Sources of Physical and Chemical Data Index",
"author_names": [
"Robert C Weast",
"Melvin Jensen Astle",
"William H Beyer",
"Samuel M Selby",
"David R Lide",
"H P R Frederikse",
"William M Haynes",
"Thomas J Bruno"
],
"corpus_id": 222665132,
"doc_id": "222665132",
"n_citations": 157,
"n_key_citations": 0,
"score": 0,
"title": "Handbook of chemistry and physics a ready reference pocket book of chemical and physical data",
"venue": "",
"year": 1922
},
{
"abstract": "Maxwell's equations state that a dielectric metallic interface can support surface plasmon polaritons (SPPs) which are coherent electron oscillation waves that propagate along the interface with an electromagnetic wave. The unique properties of the interface waves result from the frequency dependent dispersion characteristics of metallic and dielectric materials. This chapter provides an introduction to alternative plasmonic materials, as well as the rationale for each material choice. The comprehensive optical properties of various materials, including noble metals and semiconductors, are presented. The optical properties are evaluated based on the permittivity and permeability defined by either the Drude or Lorentz model. Furthermore, the noble metals are described from the generally approved data in a general handbook of solid materials, such as the Handbook of Optical Constants of Solids, edited by Palik. This chapter outlines the effective medium approaches for describing the effective dielectric functions of composite nanostructures. It also provides a reference for finding better plasmonic materials at specific frequencies.",
"author_names": [],
"corpus_id": 44110632,
"doc_id": "44110632",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Chapter 1 Optical Properties of Plasmonic Materials",
"venue": "",
"year": 2017
},
{
"abstract": "Maxwell's equations state that a dielectric metallic interface can support surface plasmon polaritons (SPPs) which are coherent electron oscillation waves that propagate along the interface with an electromagnetic wave. The unique properties of the interface waves result from the frequency dependent dispersion characteristics of metallic and dielectric materials. This chapter provides an introduction to alternative plasmonic materials, as well as the rationale for each material choice. The comprehensive optical properties of various materials, including noble metals and semiconductors, are presented. The optical properties are evaluated based on the permittivity and permeability defined by either the Drude or Lorentz model. Furthermore, the noble metals are described from the generally approved data in a general handbook of solid materials, such as the Handbook of Optical Constants of Solids, edited by Palik. This chapter outlines the effective medium approaches for describing the effective dielectric functions of composite nanostructures. It also provides a reference for finding better plasmonic materials at specific frequencies.",
"author_names": [
"Yongqian Li"
],
"corpus_id": 136378976,
"doc_id": "136378976",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Optical Properties of Plasmonic Materials",
"venue": "",
"year": 2017
},
{
"abstract": "S. E. Miller and I. P. Kaminow, Eds. Optical Fiber Telecommunications II, San I. P. Kaminow and A. E. Siegman, Eds. Laser Devices and Applications, IEEE, 1973. I. P. Kaminow, \"Foreword,\" in Handbook of Optical Constants of Solids, I. P. Kaminow, \"Book Review: Integrated Optics: Theory and Technology, ed. If you want to get Handbook of Fiber Optics: Theory and Applications pdf eBook copy write by good author Wolf, Helmut F. you can download the book copy. G. L. Cariolaro, \"Error probability in digital fiber optic communication systems,\" IEEE Trans. M. G. Kendall and A. Stuart, The Advanced Theory of Statistics (Hafer, New detection with application to FSK fiber optic communications,\" IEEE Trans. M. Abramowitz and I. E. Stegun, Handbook of Mathematical Functions (U.S.",
"author_names": [
"Helmut F Wolf"
],
"corpus_id": 57647747,
"doc_id": "57647747",
"n_citations": 38,
"n_key_citations": 1,
"score": 0,
"title": "Handbook of fiber optics theory and applications",
"venue": "",
"year": 1979
}
] |
Efficient planar heterojunction perovskite solar cells by vapour deposition | [
{
"abstract": "Many different photovoltaic technologies are being developed for large scale solar energy conversion. The wafer based first generation photovoltaic devices have been followed by thin film solid semiconductor absorber layers sandwiched between two charge selective contacts and nanostructured (or mesostructured) solar cells that rely on a distributed heterojunction to generate charge and to transport positive and negative charges in spatially separated phases. Although many materials have been used in nanostructured devices, the goal of attaining high efficiency thin film solar cells in such a way has yet to be achieved. Organometal halide perovskites have recently emerged as a promising material for high efficiency nanostructured devices. Here we show that nanostructuring is not necessary to achieve high efficiencies with this material: a simple planar heterojunction solar cell incorporating vapour deposited perovskite as the absorbing layer can have solar to electrical power conversion efficiencies of over 15 per cent (as measured under simulated full sunlight) This demonstrates that perovskite absorbers can function at the highest efficiencies in simplified device architectures, without the need for complex nanostructures.",
"author_names": [
"Mingzhen Liu",
"Michael B Johnston",
"Henry J Snaith"
],
"corpus_id": 205235359,
"doc_id": "205235359",
"n_citations": 5901,
"n_key_citations": 52,
"score": 1,
"title": "Efficient planar heterojunction perovskite solar cells by vapour deposition",
"venue": "Nature",
"year": 2013
},
{
"abstract": "Hybrid organic inorganic solar photovoltaic (PV) cells capable of directly converting sunlight to electricity have attracted much attention in recent years. Despite evident technological advancements in the PV industry, the widespread commercialisation of solar cells is still being mired by their low conversion efficiencies and high cost per Watt. Perovskites are an emerging class of semiconductors providing a low cost alternative to silicon based photovoltaic cells, which currently dominate the market. This thesis develops a series of studies on \"all solid state perovskite solar cells\" fabricated via vapour deposition which is an industrially accessible technique, to achieve planar heterojunction architectures and efficient PV devices. Chapter 2 presents a general outlook on the operating principles of solar cells, delving deeper into the specific operational mechanism of perovskite solar cells. It also explores the usual methods employed in the fabrication of perovskite thin films. Chapter 3 describes the experimental procedures followed during the fabrication of the individual components constituting the device from the synthesis of the precursors to the construction of the functioning perovskite PV devices. Chapter 4 demonstrates pioneering work involving the dual source vapour deposition (DSVD) of planar heterojunction perovskite solar cells which generated remarkable power conversion efficiency values surpassing 15% These significant results pave the way for the mass production of perovskite PVs. To further expand the range of feasible vapour deposition techniques, a two layer sequential vapour deposition (SVD) technique is explored in Chapter 5. This chapter focusses on identifying the factors affecting the fundamental properties of the vapour deposited films. Findings provide an improved understanding of the effects of precursor compositions and annealing conditions on the films. Chapter 5 concludes with a comparison between SVD and DSVD fabricated films, highlighting the benefits of each vapour deposition technique. Furthermore, hysteretic effects are analysed in Chapter 6 for the perovskite PV devices fabricated based on different structural configurations. An interesting discovery involving the temporary functioning of compact layer free perovskite PV devices suggests the presence of a built in field responsible for the hysteresis of the cells. The observations made in this chapter yield a new understanding of the functionality of individual cell layers. Combining the advantages of the optimum vapour deposition technique established in Chapter 4 and Chapter 5, with the enhanced understanding of perovskite PV cell operational mechanism acquired from Chapter 6, an ongoing study on an \"all perovskite\" tandem solar cell is introduced in Chapter 7. This demonstration of the \"all perovskite\" tandem devices confirms the versatility of perovskites for a broader range of PV applications.",
"author_names": [
"Mingzhen Liu"
],
"corpus_id": 94466500,
"doc_id": "94466500",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Planar heterojunction perovskite solar cells via vapour deposition and solution processing",
"venue": "",
"year": 2014
},
{
"abstract": "Recently, hybrid perovskite solar cells (PSCs) have attracted extensive attention due to their high efficiency and simple preparing process. Herein, a facile low pressure chemical vapor deposition (LPCVD) technology is first developed to fabricate PSCs, which can effectively reduce the over rapid intercalating reaction rate and easily overcome this blocking issue during the solution process. As a result, the prepared uniform perovskite films exhibit good crystallization, strong absorption, and long carrier diffusion length. More strikingly, CH3NH3PbI3 absorbers by LPCVD demonstrate excellent moisture resistant feature even under laser illumination and high temperature conditions, which indicates that our proprietary method is very suitable for the future low cost, nonvacuum production of the new generation photovoltaic devices. Finally, high efficiency of 12.73% is successfully achieved under fully open air conditions. To the best of our knowledge, this is the first report of efficient PSCs with such a high humidity above 60%",
"author_names": [
"Paifeng Luo",
"Zhaofan Liu",
"Wei Xia",
"Chenchen Yuan",
"Ji-gui Cheng",
"Yingwei Lu"
],
"corpus_id": 38367062,
"doc_id": "38367062",
"n_citations": 137,
"n_key_citations": 1,
"score": 0,
"title": "Uniform, stable, and efficient planar heterojunction perovskite solar cells by facile low pressure chemical vapor deposition under fully open air conditions.",
"venue": "ACS applied materials interfaces",
"year": 2015
},
{
"abstract": "High performance planar heterojunction (PHJ) perovskite solar cells (PrSCs) with MAPbI3 perovskite films were fabricated using a facile, environmentally benign, efficient and low cost dip coating deposition approach on a bilayered ZnO/TiO2 electron transport system from aqueous non halide Pb(NO3)2. Outstanding performance of PrSCs was achieved due to the PHJ configuration of FTO/TiO2/ZnO/MAPbI3/spiro OMeTAD/MoO3/Ag. These PHJ PrSCs exhibited better performance and stability with thinner ZnO layers in contrast to those with mesoporous TiO2 scaffolds, indicating that the thickness of the ZnO layer in the PHJ architecture significantly affected the surface coverage, morphology, crystallinity, and stability of the MAPbI3 perovskite films processed by dip coating deposition.",
"author_names": [
"Muhammad Adnan",
"Jae Kwan Lee"
],
"corpus_id": 213752384,
"doc_id": "213752384",
"n_citations": 16,
"n_key_citations": 0,
"score": 0,
"title": "Highly efficient planar heterojunction perovskite solar cells with sequentially dip coated deposited perovskite layers from a non halide aqueous lead precursor",
"venue": "",
"year": 2020
},
{
"abstract": "We report the use of ultra sonic spray coating under ambient conditions as a deposition technique for the fabrication of planar heterojunction CH3NH3PbI3 xClx perovskite solar cells. We make a first optimization of processing parameter space using this deposition technique, and explore the role of the temperature of the substrate during spray casting, the volatility of the casting solvent and the post deposition anneal on determining the efficiency of the resultant solar cells. We find that maximum device efficiency is correlated with the creation of dense films having a surface coverage above 85% When such films are incorporated into a solar cell device, power conversion efficiencies of up to 11% are realized. These results demonstrate that spray coating can be used in the large area, low cost manufacture of high efficiency solution processed perovskite solar cells.",
"author_names": [
"Alexander T Barrows",
"Andrew J Pearson",
"Chankyu Kwak",
"Alan D F Dunbar",
"Alastair Buckley",
"David G Lidzey"
],
"corpus_id": 52512256,
"doc_id": "52512256",
"n_citations": 513,
"n_key_citations": 6,
"score": 0,
"title": "Efficient planar heterojunction mixed halide perovskite solar cells deposited via spray deposition",
"venue": "",
"year": 2014
},
{
"abstract": "Abstract Ultrathin and compact SnOx amorphous layers derived from SnCl4 were introduced at the interface of electron transport layer (ETL)/perovskite or FTO/ETL to enhance the electron coupling between layers, passivate the trapping defects and optimize the energy level alignment. As results of the increased interface electron collection and reduced interface recombination, the planer perovskite solar cell (PSC) with SnO2 nanocrystal (NC) ETL pre treated by SnCl4 (Cl SnO2) shows the power conversion efficiency (PCE) enhancement from 16.3% to 18.6% and the device hysteresis has also been significantly restrained. In comparison, the planer PSCs with traditional SnCl4 (SnO2 Cl) post treated SnO2 NC ETL makes the PCE increased from 16.3% to 17.3% These results indicate that both two kinds of treated ways could improve the performance of the PSCs but compared with the post treatment process, the devices based on Cl SnO2 pre treated ETL present superior performance, which is attributed to the closer contact and enhanced electron coupling between FTO and SnO2 NC ETL with Cl SnO2 in between.",
"author_names": [
"Danli Zhang",
"Hanmin Tian",
"Shixiao Bu",
"Tingting Yan",
"Jinfeng Ge",
"Tao Lei",
"Wengang Bi",
"Like Huang",
"Ziyi Ge"
],
"corpus_id": 216443485,
"doc_id": "216443485",
"n_citations": 15,
"n_key_citations": 0,
"score": 0,
"title": "Efficient planar heterojunction perovskite solar cells with enhanced FTO/SnO2 interface electronic coupling",
"venue": "",
"year": 2020
},
{
"abstract": "Introduction of Cs into FAPbI3 displayed great potential to stabilize the black perovskite phase by forming FA1 xCs xPbI3, which has been investigated widely based on solution process. During solution processing, the over rapid intercalating reaction rate between PbI2 and A cations (FA+ and Cs+ can bring some undesirable structural transitions. However, in vapor assisted solution process (VASP) the over rapid intercalating reaction rate can be reduced effectively. In addition, the formation process can be regulated significantly by the intermediate perovskite phase. In this study, FACl was employed together with FAI to improve the FA0.9Cs0.1PbI3 films by VASP. In the vapor deposition process, the FACl and FAI vapor coreacted with the PbI2 solid films, preferentially forming the intermediate perovskite phase FA0.9Cs0.1PbI xCl y. The intermediate perovskite phase FA0.9Cs0.1PbI xCl y supplied a plenty of seeds for rapid nucleation of perovskite, which prolonged the crystallization time of FA0.9Cs0.1PbI3, and thus, a smooth FA0.9Cs0.1PbI3 film with suppressed nonradiative recombination, prolonged carrier lifetime and decreased trap state density was acquired. Corresponding planar heterojunction perovskite solar cells achieved a champion power conversion efficiency (PCE) of 16.39% with a Voc of 0.99 V, Jsc of 22.87 mA/cm2, and fill factor of 74.82% under reverse scanning. Meanwhile, a hysteresis index of the FACl 10 device was decreased to 0.024 compared with 0.075 of the control device. Moreover, under the condition of nitrogen atmosphere, the normalized PCE of FACl 10 device diminished only 4.9% which was more stable comparing with 31.88% diminishing of the control device after 30 days.",
"author_names": [
"Jing Chen",
"Jia Xu",
"Chenxu Zhao",
"Bing Zhang",
"Xiaolong Liu",
"Songyuan Dai",
"Jianxi Yao"
],
"corpus_id": 58542311,
"doc_id": "58542311",
"n_citations": 13,
"n_key_citations": 0,
"score": 0,
"title": "Efficient Planar Heterojunction FA1 xCs xPbI3 Perovskite Solar Cells with Suppressed Carrier Recombination and Enhanced Open Circuit Voltage via Anion Exchange Process.",
"venue": "ACS applied materials interfaces",
"year": 2019
},
{
"abstract": "The in situ thermal annealing doctor blading was developed to fabricate high quality perovskite CH3NH3PbI3 thin film and efficient planar heterojunction perovskite solar cells (PHJ PSCs) in ambient condition with humidity of ~45% The morphology of CH3NH3PbI3 thin film fabricated by in situ thermal annealing doctor blading varied from random nanowires to oriented domains as increasing the substrate temperature, and the domain size became larger and larger with increasing substrate temperature. The PHJ PSCs with a structure of ITO/PEDOT:PSS/CH3NH3PbI3/PCBM/Ag was fabricated based on in situ thermal annealing doctor bladed CH3NH3PbI3 thin film in ambient condition, resulting in the power conversion efficiency up to 11.29% without obvious hysteresis under different scanning directions and speeds. The performance is comparable to that of PHJ PSCs fabricated by spin coating deposition in glovebox with the same structure. The research results suggested that efficient PHJ PSCs could be fabricated by large scale in situ thermal annealing doctor blading in ambient condition, which is matchable with large scale, roll to roll process and shows potential application in industrial production.",
"author_names": [
"Han Wu",
"Chujun Zhang",
"Kongxian Ding",
"Lijuan Wang",
"Yongli Gao",
"Junliang Yang"
],
"corpus_id": 99945278,
"doc_id": "99945278",
"n_citations": 76,
"n_key_citations": 0,
"score": 0,
"title": "Efficient planar heterojunction perovskite solar cells fabricated by in situ thermal annealing doctor blading in ambient condition",
"venue": "",
"year": 2017
},
{
"abstract": "Abstract Obtaining high quality organic inorganic halide perovskite films that have smooth and continuous surfaces and large crystal domains and possess photoelectrical properties preferable for photovoltaic applications is of paramount importance to achieve high performance perovskite solar cells (PSCs) The introduction of other halide ions into the synthesis process of methylammonium lead triiodide, CH 3 NH 3 PbI 3 to fabricate CH 3 NH 3 PbI 3 x X x (X=Cl or Br) x 0) has been confirmed as an effective approach to optimize optoelectronic properties, thereby enhancing solar cell performance. However, the reported approaches to incorporate chlorine or bromine in perovskite films mainly take place during a liquid phase synthesis process. Here, we report on bromide regulated CH 3 NH 3 PbI 3 film formation through a low pressure vapor assisted deposition process. PbBr 2 was used to either replace or to be mixed with PbI 2 to form pre deposited films that were then reacted with CH 3 NH 3 I vapor. Detailed structural, spectroscopic, and morphological characterizations of the perovskite films unambiguously demonstrate the formation of CH 3 NH 3 PbI 3 films. However, bromine incorporation slows down the perovskite formation process through formation of an intermediate phase, CH 3 NH 3 PbBr x I y which improves the grain domains in the as fabricated perovskite films. Enhancements in power conversion efficiency (PCE) for the as fabricated planar heterojunction structured PSCs were found for samples in which bromine was incorporated. Meanwhile, transient photovoltage decay measurements revealed that carrier recombination was suppressed throughout the entire device. When mixed PbI 2 /PbBr 2 films with a molar ratio of 1:4 were used as re deposited films, an optimized PCE of 17.40% was obtained.",
"author_names": [
"Jia Xu",
"Jian-nan Yin",
"Li Xiao",
"Bing Zhang",
"Jianxi Yao",
"Songyuan Dai"
],
"corpus_id": 99903804,
"doc_id": "99903804",
"n_citations": 18,
"n_key_citations": 0,
"score": 0,
"title": "Bromide regulated film formation of CH3NH3PbI3 in low pressure vapor assisted deposition for efficient planar heterojunction perovskite solar cells",
"venue": "",
"year": 2016
},
{
"abstract": "Abstract TiO2 is a best choice of electron transport layers in perovskite solar cells, due to its high electron mobility and stability. However, traditional TiO2 processing method requires rather high annealing temperature >500 degC) preventing it from application to flexible devices. Here, we show that TiO2 thin films can be synthesized via chemical bath deposition below 100 degC. Typically, a compact layer of rutile TiO2 is deposited onto fluorine doped tin oxide (FTO) coated substrates, in an aqueous TiCl4 solution at 70 degC. Through the optimization of precursor concentration and ultraviolet ozone surface modification, over 12% power conversion efficiency can be achieved for CH3NH3PbI3 based perovskite solar cells. These findings offer a potential low temperature technical solution in using TiO2 thin film as an effective transport layer for flexible perovskite solar cells.",
"author_names": [
"Chao Liang",
"Wu Zhenhua",
"Pengwei Li",
"Jiajie Fan",
"Z Yiqiang",
"Guosheng Shao"
],
"corpus_id": 100441431,
"doc_id": "100441431",
"n_citations": 58,
"n_key_citations": 0,
"score": 0,
"title": "Chemical bath deposited rutile TiO2 compact layer toward efficient planar heterojunction perovskite solar cells",
"venue": "",
"year": 2017
}
] |
Organic Semiconductors for Thermoelectric Applications | [
{
"abstract": "The thermoelectric performance of thin films fabricated from two commercially available, highly conductive polymer formulations based on poly (3,4 ethylendioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was investigated. In order to enhance the electrical conductivity, the high boiling solvent dimethyl sulfoxide (DMSO) was added. By changing the content of DMSO the electrical conductivity was increased by a factor of two without changing the Seebeck coefficient or the thermal conductivity. We achieved ZT 9.2 x 10 3 at room temperature upon the addition of 5 vol. DMSO to the PEDOT:PSS formulation.",
"author_names": [
"M Scholdt",
"Hung Manh Do",
"John F Lang",
"Andre Gall",
"Alexander Colsmann",
"Uli Lemmer",
"Jan D Koenig",
"Mark T Winkler",
"Harald Dr Boettner"
],
"corpus_id": 96124064,
"doc_id": "96124064",
"n_citations": 100,
"n_key_citations": 2,
"score": 1,
"title": "Organic Semiconductors for Thermoelectric Applications",
"venue": "",
"year": 2010
},
{
"abstract": "Doping is essential to manipulate the electrical performance of both thermoelectric (TE) materials and organic semiconductors (OSCs) Although organic thermoelectric (OTE) materials have experienced a rapid development over the past decade, the chemical doping of OSCs for TE applications lags behind, which has limited further breakthroughs in this cutting edge field. Recently, increasing efforts have been devoted to the development of energetically matched host and dopant molecules, exploring novel doping methods and revealing the doping mechanisms. This tutorial review covers the basic mechanisms, fundamental requirements, recent advances and remaining challenges of chemical doping in OSCs for TE applications. We first present the basic knowledge of the trade off relationship in TE materials and its critical requirements for doped OSCs, followed by a brief introduction of recent advances in the molecular design of OSCs and dopants. Moreover, we provide an overview of the existing categories of doping mechanisms and methods, and more importantly, emphasize the summarized doping strategies for the state of the art OTE materials. Finally, challenges and perspectives on the chemical doping of OSCs are proposed to highlight the research directions that deserve attention towards a bright future of OTE materials.",
"author_names": [
"Wenrui Zhao",
"Jiamin Ding",
"Ye Zou",
"Chong-an Di",
"Daoben Zhu"
],
"corpus_id": 221918356,
"doc_id": "221918356",
"n_citations": 11,
"n_key_citations": 0,
"score": 0,
"title": "Chemical doping of organic semiconductors for thermoelectric applications.",
"venue": "Chemical Society reviews",
"year": 2020
},
{
"abstract": "First principles band structure calculations coupled with the Boltzmann transport theory are used to study the thermoelectric properties in pentacene and rubrene crystals. In the constant relaxation time and rigid band approximations, the electronic contribution to the Seebeck coefficient is obtained. The absolute value of Seebeck coefficient and its temperature and carrier density dependences are in quantitative agreement with the recent field effect modulated measurement. The dimensionless thermoelectric figure of merit is further evaluated based on the calculated transport coefficients and experimental parameters. The peak values of figure of merit in pentacene fall in the range of 0.8 1.1, which are close to those of the best bulk thermoelectric materials. Our investigations show that organic semiconductors can be potentially good thermoelectric materials for near room temperature applications.",
"author_names": [
"Dong Wang",
"Ling Tang",
"Mengqiu Long",
"Zhigang Shuai"
],
"corpus_id": 33925419,
"doc_id": "33925419",
"n_citations": 66,
"n_key_citations": 1,
"score": 0,
"title": "First principles investigation of organic semiconductors for thermoelectric applications.",
"venue": "The Journal of chemical physics",
"year": 2009
},
{
"abstract": "We have predicted that organic semiconductor crystals with several percent carrier doping might show a considerable thermoelectric effect caused by transition in conduction mechanism from hopping to band like[1] Figure 1 shows the simulated density of states of thin film phase pentacene which shows narrowing of HOMO states as the temperature is lowered due to decreased thermal motion of the molecule. If the carriers are chemically doped to the organic semiconductors, it can be expected that the narrowing will lead to the shift in the Fermi energy which can be estimated as",
"author_names": [
"Yuji Ikuta",
"Yuya Tsuchida",
"Naoki Muraya",
"Taro Nagahama",
"Toshihiro Shimada"
],
"corpus_id": 99584052,
"doc_id": "99584052",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Bulk crystal growth of organic semiconductors for thermoelectric applications",
"venue": "",
"year": 2011
},
{
"abstract": "Organic thermoelectric (OTE) materials have attracted intensive attention because of their promising applications in flexible electricity generators and ultrathin solid cooling elements. The well d.",
"author_names": [
"Fengjiao Zhang",
"Chong-an Di"
],
"corpus_id": 216248267,
"doc_id": "216248267",
"n_citations": 17,
"n_key_citations": 0,
"score": 0,
"title": "Exploring Thermoelectric Materials from High Mobility Organic Semiconductors",
"venue": "",
"year": 2020
},
{
"abstract": "Unlike the conventional p doping of organic semiconductors (OSCs) using acceptors, here, an efficient doping concept for diketopyrrolopyrrole based polymer PDPP[T]2 EDOT (OSC 1) is presented using an oxidized p type semiconductor, Spiro OMeTAD(TFSI)2 (OSC 2) exploiting electron transfer from HOMOOSC 1 to HOMOOSC 2 A shift of work function toward the HOMOOSC 1 upon doping is confirmed by ultraviolet photoelectron spectroscopy (UPS) Detailed X ray photoelectron spectroscopy (XPS) and UV vis NIR absorption studies confirm HOMOOSC 1 to HOMOOSC 2 electron transfer. The reduction products of Spiro OMeTAD(TFSI)2 to Spiro OMeTAD(TFSI) and Spiro OMeTAD is also confirmed and their relative amounts in doped samples is determined. Mott Schottky analysis shows two orders of magnitude increase in free charge carrier density and one order of magnitude increase in the charge carrier mobility. The conductivity increases considerably by four orders of magnitude to a maximum of 10 S m 1 for a very low doping ratio of 8 mol% The doped polymer films exhibit high thermal and ambient stability resulting in a maximum power factor of 0.07 uW m 1 K 2 at a Seebeck coefficient of 140 uV K 1 for a very low doping ratio of 4 mol% Also, the concept of HOMOOSC 1 to HOMOOSC 2 electron transfer is a highly efficient, stable and generic way to p dope other conjugated polymers.",
"author_names": [
"Mahima Goel",
"Marie Siegert",
"Gert Krauss",
"John Mohanraj",
"Adrian Hochgesang",
"David C Heinrich",
"Martina Fried",
"Jens Pflaum",
"Mukundan Thelakkat"
],
"corpus_id": 221788000,
"doc_id": "221788000",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "HOMO HOMO Electron Transfer: An Elegant Strategy for p Type Doping of Polymer Semiconductors toward Thermoelectric Applications.",
"venue": "Advanced materials",
"year": 2020
},
{
"abstract": "Abstract Thermoelectrics currently attracts considerable attention as a promising branch in the field of organic electronics, with the prospect that organic semiconductors (OSCs) allow the development of light, flexible, and inexpensive thermoelectric devices, which act as alternative power sources, generating electricity from heat gradients. Thermoelectric generators are solid state devices that convert heat directly to electricity. They do not contain any moving parts and are able to operate over an extended period of time, and furthermore can function with small heat sources and limited temperature differences, which facilitates their use in situations where traditional engines are not feasible. The absence of moving parts, low need for maintenance, and a large variety of possible device architectures render organic thermoelectrics attractive for numerous applications, ranging from waste heat recovery to wearable textiles. In this chapter, we give a short introduction to the fundamentals of the thermoelectric effect, as well as to the design principles for thermoelectric generators and their characterization. Furthermore, we discuss the role of doping (i.e. the introduction of charge carriers through the addition of dopant molecules) and of the nanostructure and present strategies for the optimization of the thermoelectric properties of OSCs. Finally, we give an overview of processing methods and point out major achievements, as well as the remaining challenges.",
"author_names": [
"Anna I Hofmann",
"Renee Kroon",
"Christian Muller"
],
"corpus_id": 139369949,
"doc_id": "139369949",
"n_citations": 8,
"n_key_citations": 0,
"score": 0,
"title": "Doping and processing of organic semiconductors for plastic thermoelectrics",
"venue": "",
"year": 2019
},
{
"abstract": "Thermoelectric materials with stable mechanical and chemical properties at high temperature are required for power generation applications. For example, gas temperatures up to 1000degC are normally present in the waste stream of industrial processes and this can be used for electricity generation. There are few semiconductor materials that can operate effectively at these high temperatures. One solution may be the use of wide bandgap materials, and in particular GaN based materials, which may offer a traditional semiconductor solution for high temperatures thermoelectric power generation. In particular, the ability to both grow GaN based materials and fabricate them into devices is well understood if their thermoelectric properties are favorable. To investigate the possibility of using III Nitride and its alloys for thermoelectric applications, we synthesized and characterized room temperature thermoelectric properties of metal organic chemical vapor deposition grown GaN and InGaN with different carrier concentrations and indium compositions. The promising value of Seebeck coefficients and power factors of Si doped GaN and InGaN indicated that these materials are suitable for thermoelectric applications.",
"author_names": [
"Bahadir Kucukgok",
"Qinyue He",
"A Carlson",
"Andrew Geier Melton",
"Ian T Ferguson",
"Na Lu"
],
"corpus_id": 138718296,
"doc_id": "138718296",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Investigation of Wide Bandgap Semiconductors for Thermoelectric Applications",
"venue": "",
"year": 2013
},
{
"abstract": "The feasibility of using organic thermoelectric devices to power sensors for different applications is a critical area of interest for researchers. Organic semiconductors possess lower thermoelectric performance than their inorganic counterparts, however, this can be compensated for by certain advantages, such as their light weight, low fabrication costs, and low fabrication temperatures. For practical applications, they face competition with Li ion batteries, which are known for their high energy densities and long lifetimes. Thus, in addition to having a suitable corresponding power output, ideal organic thermoelectric devices require excellent stability. In this study, such a perspective was examined via primarily focusing on recent studies of organic thermoelectric devices and, particularly, their practical applications. The impact of contact resistance on device performance has been discussed, together with suggestions of certain promising device structures for organic thermoelectric devices. Experimentally, it was confirmed that light and compact organic thermoelectric devices with a size of ~10 cm2 should be sufficiently suitable to power sensors. Moreover, these devices were confirmed to operate under natural cooling conditions without a heat sink, thus showing excellent stability for >70 days under continuous working conditions at 100 degC.",
"author_names": [
"Masakazu Mukaida",
"Kazuhiro Kirihara",
"Shohei Horike",
"Qingshuo Wei"
],
"corpus_id": 225110078,
"doc_id": "225110078",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Stable organic thermoelectric devices for self powered sensor applications",
"venue": "",
"year": 2020
},
{
"abstract": "Abstract Organic semiconductors have traditionally been studied for applications related to light emission (LEDs) light absorption (solar cells) and logic (transistors) As of recent years, there has been an additional interest in thermoelectric applications, which goes hand in hand with an increased interest in doping these materials as thermoelectric applications require highly conductive active materials. At the date of writing, the (sub)field of organic thermoelectrics is still in rapid development and has not yet converged on a (set of) quantitative and physics based pictures in which electrical and thermal conductivity and thermopower of doped organic semiconductors can be understood. Such models would be needed to arrive at design rules for optimal performance that have predictive power. At the same time, clear trends are visible in the field. The purpose of this chapter is first to provide an overview of recent experimental results, focusing not on (record) numbers but rather on generic trends. In the second, larger part of this chapter, a critical review of currently available interpretational frameworks is given, and the predictions of these models are compared to the experimental results. The chapter ends with a short outlook.",
"author_names": [
"Dorothea Scheunemann",
"Martijn Kemerink"
],
"corpus_id": 224877215,
"doc_id": "224877215",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Thermoelectric properties of doped organic semiconductors",
"venue": "",
"year": 2021
}
] |
Power electronics masters thesis topic | [
{
"abstract": "The importance of technology and electronics in our daily life is constantly increasing. At the same time portability and energy efficiency are currently some of the hottest topics. This creates a huge need for power converters in a compact form factor and with high efficiency, which can supply these electronic devices. This calls for new technologies in order to miniaturize the power electronics of today. One way to do this is by increasing the switching frequency dramatically and develop very high frequency switch mode power supplies. If these converters can be designed to operate efficiently, a huge size, weight and cost reduction can be achieved due to the smaller energy storing elements needed at these frequencies. The research presented in this thesis focuses on exactly this. First various technologies for miniaturization of power supplies are studied, e.g. piezo electric transformers, wide band gap semiconductors and integrated power supplies. Afterwards a wide range of topologies suited for operation at very high frequencies is investigated and the most promising ones are tested experimentally. Through a comparison of these topologies the class DE inverter is found to be superior to the other alternatives, at least for converters with hundreds of volts as input and a few tens of watts output power. A class DE inverter does however require a high side gate drive, which have never been presented before for these frequencies and voltages. This thesis presents the worlds first high side gate drive capable of operating at these frequencies and voltage levels. With this gate drive the worlds first class DE inverter operating at very high frequencies with more than 100 V input is also developed and presented. These achievements are considered huge breakthroughs in the development of technologies for very high frequency switch mode power supplies. At these highly elevated frequencies normal bulky magnetics with heavy cores consisting of rare earth materials, can be replaced by air core inductors embedded in the printed circuit board. This is investigated thoroughly and both spirals, solenoids and toroids are considered, both for use as inductors and transformers. Two control methods are also investigated, namely burst mode control and outphasing. It is shown that a very flat efficiency curve can be achieved with burst mode. A 89.5% efficient converter is implemented and the efficiency only drops 5% at 10% load. This is some of the highest efficiencies presented for converters operating at these frequencies. Burst mode control does however have two major drawbacks,",
"author_names": [
"Mickey Pierre Madsen"
],
"corpus_id": 113709541,
"doc_id": "113709541",
"n_citations": 7,
"n_key_citations": 2,
"score": 0,
"title": "Very High Frequency Switch Mode Power Supplies. Miniaturization of Power Electronics.",
"venue": "",
"year": 2015
},
{
"abstract": "In recent decades, improvements in power electronics have led to a significant spread of grid connected converters, both for AC and DC applications. These converters are often interconnected together into a complex, typically non linear power system, where the interaction between harmonics at the various interfaces of the network can lead to unstable operation mode. Hence, the development of methods in order to perform stability analysis of power systems has been a challenging topic for researchers. The analysis of DC and balanced three phase AC systems has been widely studied and precise methods have been developed. However, in the case of single phase or unbalanced three phase systems, the analysis is more complex and at the beginning of this project it was still an open field for research. Thus, with focus on the latter systems, this thesis presents the stability analysis approach derived in the Linear Time Periodic (LTP) framework. Given a general power system, this is split into a source and a load subsystem. At the point of common coupling, small signal current injections are performed in order to measure the harmonic matrix impedances of source and load. Then, LTP Nyquist Criterion is applied to the ratio of the two harmonic impedances. This allows one to perform stability analysis of any system, without the requirement of knowing its structure or its parameter values. Hence this can be referred to as a \"black box approach\" Furthermore, in order to provide a theoretical validation of the method, several systems have been analysed and their LTP models have been analytically calculated and validated through simulation and experimental results. The harmonic impedances have been experimentally measured using a so called Stability Measurement Unit (SMU) which is an independent converter that performs small signal current injections and records voltage and currents perturbations. The recorded data has been post processed in Matlab to calculate harmonic impedances and LTP Nyquist. A precise stability boundaries identification has been obtained for all the analysed systems.",
"author_names": [
"Valerio Salis"
],
"corpus_id": 201879861,
"doc_id": "201879861",
"n_citations": 0,
"n_key_citations": 0,
"score": 1,
"title": "Stability analysis of AC power system in the linear time periodic framework",
"venue": "",
"year": 2019
},
{
"abstract": "The integration of renewable resources at urban and building scale is one of the major challenges that the cities of the XXI century will face in reducing greenhouse gases emissions and becoming Smart cities. From solar systems, small wind turbines and in pipe hydro systems, to Heat pumps and Micro Combined Heat and Power Fuel Cell Systems, up to energy harvesting systems from roads, pavements, urban furniture and electric vehicles, there are more and more successful cases of application of these clean technologies on new and existing buildings and districts in order to achieve zero energy buildings (ZEB) and to reduce the consumption of fossil energy in urban areas. Here is presented an overview of the different types of renewable energy sources in development, or already available, and illustrates their possible integration at the urban and building scale, showing the benefits achievable in terms of energy production, environmental impacts and architectural quality, taking into account demand response, energy storage and electric grid integration issues. 2016 APCBEES ROME CONFERENCES 12 Keynote Speaker II Prof. Jacek Namiesnik Head of Department of Analytical Chemistry, Faculty of Chemistry, Gdansk University of Technology, Poland Recent posts: 1996 2002 2005 2012 Dean of Chemical Faculty, Gdansk University of Technology 1995 Head of the Department of Analytical Chemistry at the Chemical Faculty, Gdansk University of Technology 1996 Member of the Senate of Gdansk University of Technology 2007 Chairman of the Committee of Analytical Chemistry of the Polish Academy of Sciences (PAS) 2007 Member of the State Commission for evaluation of scientific degrees and titles Degrees etc. MSc in Chemistry (Inorganic Technology) 1972, Gdansk University of Technology Ph.D. in Chemistry, 1978, Gdansk University of Technology DSc in Chemistry, 1985, Gdansk University of Technology February 1996 Scientific title of professor conferred by President of the Republic of Poland 2007 Kemula Medal (for achievements in the field of analytical chemistry) Polish Chemical Society 2008 Prime Minister Reward for scientific achievements in the field of environmental engineering 2009 Grant MASTER attributed by Foundation for Polish Science for the period of three years 2012 Sniadecki Medal for achievements in chemistry Polish Chemical Society Research interests new techniques of extraction of analytes from different types of samples, new procedures of determination of wide range of analytes from samples characterized by complex composition of the matrix, Author or coauthor of over 500 papers published in journal of JCR (IF 1231,487) number of independent citation n 4383, Hirsh index h 34. Tutor of 41 and co tutor of 8 PhD degrees. Topic: \"Microextraction Procedures as Sample Preparation Techniques for Organic Trace Constituents\" Abstract Accurate monitoring of the state of the environment requires the introduction of additional isolation and/or preconcentration steps prior to the final determination of organic pollutants because Accurate monitoring of the state of the environment requires the introduction of additional isolation and/or preconcentration steps prior to the final determination of organic pollutants because 2016 APCBEES ROME CONFERENCES 13 most analytical instruments cannot handle the matrix directly. Attention is focused on analytes separation from samples with a complex matrix composition, with high efficiency allowing they enrichment to reach detection limits of final determination technique. Another important issue is to minimize consumption of organic solvents during sample preparation procedure. In consequence, solventless procedures as well as suitable analytical equipment utilizing green solvents for the sample preparation are developed. [1] [2] Special attention is paid to microextraction techniques. Different types of such techniques have been elaborated and validated. The most widely used green sample preparation technique is Solid Phase Microextraction (SPME) used in laboratory application, also in environmental, clinical and industrial applications. Adequate sensitivity, precision and accuracy can be achieving using SPME technique coupled to typical separation and detection instruments. Interest of SPME grows along with the increasing number of new application, new technical solutions and modification of SPME devices appearing in the literature. [3] [4] The number of fibre coatings has been development to extend the applications of SPME technique for environmental application. Among broad range of the new materials applied as the retaining phase, our special emphasis is laid on the Membrane Solid Phase Microextraction technique (M SPME) In this case the polyethylene glycol (PEG) is used as very polar retaining medium physically separated from the sample by hydrophobic, thermally stable and permeable layer of polydimethylosiloxane (PDMS) which acts as a membrane. An analyte needs to be very slightly soluble in the membrane phase to effectively be isolated from an aqueous and/or gaseous media. In our studies, out so far, this system has been implemented in SPME enabling usage of the water soluble PEG without the risk of their dissolving in the polar sample matrix. This new variant of SPME has provided interesting and valuable results during studies on the extraction of polar analytes from different media. We found it applicable for the step of sample preparation in monitoring of environmental pollution. [5] Due to the unique properties, ionic liquids can be an attractive alternative to organic soolvents used currently in sample prepartion procedures. In order to determine their usefulness, new methodology for the preparation of a SPME fiber coating was elaborated. In this way the ionic liquid maintains on the fiber in a liquid state. The methodology relies on the use of sol gel technique. As a result of reaction of silica precursor in presence of ionic luiqid the silica network with pores filled with an ionic liquid is created. Selection of reaction conditions allows to change the amount of retained ionic liquid and the thickness of the final coating. Obtained ionogel fibers were used for the isolation and enrichment of aromatic organic compounds from water samples. The results showed that the ionogel coating has sufficient thermal and mechanical resistance what allows to its application in the SPME technique. [6] [1] Galuszka A. Migaszewski Z. Namiesnik J. Trends Anal. Chem, 50, 78 (2013) [2] Tobiszewski M. Mechlinska A. Zygmunt B. Namiesnik J. Trends Anal. Chem. 28, 943, (2009) [3] Spietelun A. Pilarczyk M. Kloskowski A. Namiesnik J. Chem. Soc. Rev. 39, 4524 (2010) [4] Spietelun A. Kloskowski A. Chrzanowski W. Namiesnik J. Chem. Rev. 113, 1667 (2013) [5] Kloskowski A. Pilarczyk M. Namiesnik J. Membrane Solid Phase Microextractiona new concept of sorbent preparation, Anal. Chem. 81, 7363, (2009) [6] Pena Pereira F. Marcinkowski L. Kloskowski A. Namiesnik J. Anal. Chem. 86. 11640 (2014) 2016 APCBEES ROME CONFERENCES 14 Keynote Speaker III Prof. Hartmut Hinz University of Applied Sciences, Frankfurt, Germany Prof. Hartmut Hinz was born in Duren, Germany. He received the diploma degree in electrical engineering from the University of Applied Sciences, Aachen and the Ruhr University, Bochum in Germany in the years 1990 and 1994 respectively. He received the Ph.D. degree from the Technical University, Darmstadt in Germany in 2000. From 1999 to 2009 he worked for General Motors Europe in the research department for fuel cell vehicles. In 2009 he was appointed as a Professor in power electronics at the Frankfurt University of Applied Sciences, Germany. Since 2011 he is the academic leader of the study program Energy efficiency and renewable energy. Since 2010 he is a visiting Professor at the Vietnamese German University in Ho Chi Minh City, Vietnam. His research interests are in the areas power electronics and decentralized power generation. Topic: \"Electrical Energy Storage: State of the Art\" Abstract Electrical energy storage (EES) is a well established technology in the three main application fields: storing electrical energy in order to reduce electricity costs improve the reliability of the power supply maintain and improve power quality, frequency and voltage. Nowadays the large scale penetration of distributed and renewable energy sources leads to a gaining importance of EES. Furthermore electrical energy storage is one of the essential elements in developing Smart Grids. In off grid areas, particularly in the transport sector EES is the key technology for plug in hybrid vehicles and electric vehicles. This keynote speech will present the state of the art and the future challenges of EES. First the types and features of EES are explained. Then the markets, economic benefits and technical applications are provided. Finally a forecast of the EES commercial potential is discussed. Electrical energy storage (EES) is a well established technology in the three main application fields: storing electrical energy in order to reduce electricity costs improve the reliability of the power supply maintain and improve power quality, frequency and voltage. Nowadays the large scale penetration of distributed and renewable energy sources leads to a gaining importance of EES. Furthermore electrical energy storage is one of the essential elements in developing Smart Grids. In off grid areas, particularly in the transport sector EES is the key technology for plug in hybrid vehicles and electric vehicles. This keynote speech will present the state of the art and the future challenges of EES. First the types and features of EES are explained. Then the markets, economic benefits and technical applications are provided. Finally a forecast of the EES commercial potential is discussed. 2016 APCBEES ROME CONFERENCES 15 Keynote Speaker IV Prof. Dr.",
"author_names": [
"Jerry W Dunn",
"Young-Bae Park",
"Hee-Jeong Park",
"Ibrahim Girginand",
"Cuneyt Ezgi",
"Metin Gumus",
"Seema Unnikrishnan",
"Ahmet Serdar Yilmaz",
"J Seo"
],
"corpus_id": 53127643,
"doc_id": "53127643",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Tuesday Time 13 30 16 15 Venue Room II Session 2 11 presentations Topic \" Energy Power Urban Planning \"",
"venue": "",
"year": 2017
},
{
"abstract": "As the penetration of offshore wind farms continues to increase in Western Europe, the North Sea in particular is becoming more densely populated by offshore wind farms. Wind turbine wakes have been a topic of great research in the field of wind energy for some time, however the industry now seeks an understanding of the in fluence of the wake from one wind farm on the performance of a downstream wind farm. Few studies have been conducted to this end. This project will contribute to the greater work of the DTU OffshoreWake project. This master thesis will use 2018 SCADA data provided by the project partner, Vattenfall, meteorological mast data provided by BMWi and PTJ, and the author will conduct and analyse simulations using the Weather Research and Forecasting (WRF) model for the same time period. Additionally, this project will comment on the validity of the wind farm param eterization sub models within WRF, and investigate the dependance of wakes on climatological variables and offer a longer term study than previously conducted, therefore giving the possibility of conclusions with greater certainty based on this body of work. It is found that both of the wind farm parameterization schemes (Fitch and EWP) used in this project can reasonable replicate the trends seen in the measured data. The EWP scheme tends to over predict both gross power produc tion and mean wind speed, while the Fitch scheme tends to underpredict the same. However, for both schemes, good agreement is found with measurements when the wind speed is accurately predicted. Wind farm wakes are observed in SCADA data and WRF simulations. The magnitude of velocity deficit tends to increase for sea sons in which atmospherically stable conditions are most frequent. In the region of study, these stable conditions are accompanied by generally lower wind speeds and winds which prevail from the east.",
"author_names": [
"Erin Langor"
],
"corpus_id": 213216893,
"doc_id": "213216893",
"n_citations": 3,
"n_key_citations": 2,
"score": 0,
"title": "Characteristics of Offshore Wind Farm Wakes and their Impact on Wind Power Production from Long term Modelling and Measurements",
"venue": "",
"year": 2019
},
{
"abstract": "Bitcoin is a novel peer to peer payment network that was started in 2009 and that has since flourished, gaining acceptance all over the world. By contributing their ressources such as network connectivity and computing power, all participants are creating the the Bitcoin network together. Designed as an open source software system, the participation rules for this network are not upheld by humans, but implemented in code, and generally allow anyone to join or leave the network at will. Since the time of Bitcoin's inception, software errors had to be fixed and network attacks that tried to make parts of the network unavailable have been endured. This thesis provides a solution to the problem of illegal data inclusions within the blockchain, a data structure that cannot easily be changed and that has to be transmitted to participants of Bitcoin. The flaw, i.e. the possibility for any user of Bitcoin to potentially include illegal data and therefore illegalizes the whole blockchain, is not just a software flaw, but can be seen as a structural one if free participation and uncensorable payments are to be provided. The proposal to solve the problem is layered in two tiers. The first tier prevents effective data inclusion for some standard payment functions within Bitcoin. This allows participants to be certain that these transactions do not contain bad data, allowing them to be included into Bitcoin blocks. It also solves the problem of illegal data permanently occupying valuable ressources on Bitcoin nodes, as parts of the provably clean transactions are generally held in RAM until they have been spent. The prevention mechanism is essentially a system that provides proof that bitcoins were sent to actual Bitcoin addresses, stopping data inclusion by address fields abusal. The second tier consists of rule changes for Bitcoin. First of all, all non standard payment transactions are removed from Bitcoin, with the exception of the more computationally flexible and popular P2SH transactions. This limits the avenues for data inclusion in Bitcoin without destroying its flexibility or its smart contract capabilities. Then, P2SH transactions are redesigned to allow for a more fine grained deletion of their data, so only offending parts could be removed without destroying the integrity of the rest. Finally, a special type of transaction is introduced that allows censorship of just the signature data of a P2SH transaction. This transaction has to include a payment equal to the Bitcoin provided by the previous P2SH transaction, however. By adding this requirement, the system is protected from becoming open to money creation attacks that might inflate the currency without the agreement of all participants. With these changes, illegal data inclusion becomes either impossible, or they can be removed without destorying the integrity of the payment system as a whole or for payments that have already happened. Implementing all proposed changes would go beyond the scope of a master thesis. Tier 1 of the presented solution has been implemented as a proof of concept, though. As a basis, the most popular Bitcoin node software, Bitcoin Core, has been used. Additionally, the ideas behind tier 2 are explained in full, and the potential impact on the system is discussed.",
"author_names": [
"Andreas Seeg"
],
"corpus_id": 221719484,
"doc_id": "221719484",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Hardening Bitcoin against off topic data inclusion attacks",
"venue": "",
"year": 2018
},
{
"abstract": "Computer simulation techniques are essential to electric power system studies to reduce risks and improve reliability. Modern power systems are undergoing significant changes with better monitoring and communication capabilities, higher levels of renewable penetration, and a considerable number of connected power electronics devices. There arises a pressing need for a testbed with structural and functional representations of modern power systems, including wide area measurement, energy management, communication, and measurement based control. The topic of the dissertation, Large Scale Simulation of Modern Electric Power Systems, is broad. This dissertation will cover two aspects of the topic. The first aspect is the design and implementation of a communication network enabled large scale testbed (LTB) for wide area measurement based control verification. The second aspect is the modeling and control of voltage source converter (VSC) based multi terminal dc (MTDC) networks. In detail, the LTB section introduces the concepts and techniques that are being used in the current implementation. A proposal of a cyber physical system (CPS) design for the next generation LTB follows. The VSC MT HVDC part covers a) the steady state power flow analysis of ac/ dc hybrid systems, b) positive sequence transient dynamics models of VSC with inertia emulation and frequency response capability, and c) an application of multi terminal dc for integrating offshore wind generation with inertial and frequency support. The outcome in the testbed section includes an implementation of the CURENT LTB. A decoupled architecture enabled by distributed messaging environment allows for building up a simulation environment with modules for simulation, communication, energy management, and wide area control. The LTB also features module interchangeability by adopting a unified communication format that makes the modules agnostic of each other. The testbed has successfully demonstrated state estimations, frequency control and damping control on the CURENT test systems. In the VSC based MTDC modeling section, the power flow model is able to handle systems with more than 10,000 buses at a calculation speed faster than MATLABbased open source packages. The transient models of the VSCs and the dc network demonstrate power transfer capability for inertial response and frequency control in a single grid and a multi area grid with offshore wind generations. CONTENT FROM POWID MEMBERS Author: Paulo Alberto Viana Vieira Advisor: Dr. Edson Bortoni Institute: Institute of Electrical Systems and Energy (ISEE) University: Itajuba Federal University, Brazil Abstract: Nowadays, the transition from conventional fossil fuel based and centralized energy generation to distributed renewables is increasing rapidly, due to the environmental concerns and political incentives. Wind and solar power generation offer carbon dioxide neutral electricity but also present some integration difficulties for energy system operators and planners due to intermittent power output. A promising way of dealing with the intermittency from renewables is energy storage. Many types of energy storage have been under development and study. Therefore, a battery energy storage system has been implemented mainly in residential applications to utility power grids. Battery energy storage can allow higher amounts of renewable electricity generation to be integrated by smoothening power output, and time shifting generated energy to follow demand and increase hosting capacities through peak shaving. Power quality related issues due to intermittency can be mitigated by controlling the storage's charging patterns to respond to grid variables. For optimal utilization and maximum storage value, several applications should be within the operational repertoire of the storage unit. Other applications including arbitrage, grid investment deferral, and load following are discussed. This thesis proposes a study and analysis of the Conti Varlet approach or stretchedthread method (STM) a powerful graphical based technique used to partial flow regularization for hydropower plants to provide auxiliary service regularization considering a battery energy storage system (BESS) The proposal is maintaining the power more stable and constant as possible, mitigating the PV intermittence. A one year analysis is performed for each BESS size, ranging from 10% to 90% A cost for each scenario and an optimal BESS is presented to reduce the disutility. The changing of the consumption costs is defined as disutility. Large Scale Simulation of Modern Electric Power Systems Nowadays, the transition from conventional fossil fuel based and centralized energy generation to distributed renewables is increasing rapidly, due to the environmental concerns and political incentives. Wind and solar power generation offer carbon dioxide neutral electricity but also present some integration difficulties for energy system operators and planners due to intermittent power output. A promising way of dealing with the intermittency from renewables is energy storage. Many types of energy storage have been under development and study. Therefore, a battery energy storage system has been implemented mainly in residential applications to utility power grids. Battery energy storage can allow higher amounts of renewable electricity generation to be integrated by smoothening power output, and time shifting generated energy to follow demand and increase hosting capacities through peak shaving. Power quality related issues due to intermittency can be mitigated by controlling the storage's charging patterns to respond to grid variables. For optimal utilization and maximum storage value, several applications should be within the operational repertoire of the storage unit. Other applications including arbitrage, grid investment deferral, and load following are discussed. This thesis proposes a study and analysis of the Conti Varlet approach or stretchedthread method (STM) a powerful graphical based technique used to partial flow regularization for hydropower plants to provide auxiliary service regularization considering a battery energy storage system (BESS) The proposal is maintaining the power more stable and constant as possible, mitigating the PV intermittence. A one year analysis is performed for each BESS size, ranging from 10% to 90% A cost for each scenario and an optimal BESS is presented to reduce the disutility. The changing of the consumption costs is defined as disutility. Large Scale Simulation of Modern Electric Power Systems Energy Storage System Sizing Using The Conti Varlet And Disutility Optimization",
"author_names": [
"Xinsheng Lou"
],
"corpus_id": 211203440,
"doc_id": "211203440",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "ISA Power Industries Division Newsletter",
"venue": "",
"year": 2019
},
{
"abstract": "JOONA LEINONEN: Real time Electrical Emulation of Li ion Battery Storage Using Power Hardware in the Loop Tampere University Master's Thesis, 55 pages, 3 Appendix pages June 2019 Master's Degree Programme in Computing and Electrical Engineering Major: Power Electronics Examiner: Academy Research Fellow Tomi Roinila",
"author_names": [
"Joona Leinonen"
],
"corpus_id": 207815911,
"doc_id": "207815911",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Real time Electrical Emulation of Li ion Battery Storage Using Power Hardware in the Loop",
"venue": "",
"year": 2019
},
{
"abstract": "ALEKSI SALMI: Analysis of harmonic content and power losses of a frequencyconverter fed high speed induction motor system Tampere University Master of Science Thesis, 63 pages, 4 Appendix pages January 2019 Master's Degree Programme in Electrical Engineering Major: Power Electronics Examiners: University Lecturer Jenni Rekola, Assistant Prof. Tuomas Messo",
"author_names": [
"Aleksi Salmi"
],
"corpus_id": 195551205,
"doc_id": "195551205",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Analysis of harmonic content and power losses of a frequency converter fed high speed induction motor system",
"venue": "",
"year": 2019
},
{
"abstract": "There is an increasing demand for compact onsite dielectric test systems of medium and high voltage equipment. Though there are commercially available mobile high voltage (HV) test sources, they have some important drawbacks such as limitation in voltage capability, complexity in building up the test setup and lack of versatility to test different equipment. Alternatively, the present challenges in these conventional test sources could be resolved by constructing a power electronics based test source. Amongst various converter topologies, Modular Multilevel Converter (MMC) is considered as a suitable topology for this application because of its high efficiency, modular structure, and reduced filter requirement. In order to achieve a compact solution, an oil immersed design of MMC, instead of the typical air insulated converter design is proposed in this master thesis. Oil can act both as a coolant and an effective insulating medium, thereby reducing the dimensions of the test system. This master thesis demonstrates the feasibility of oil immersed MMC based HV test source, covering both system level and component level aspects. The extent of compactness of the test source in oil was estimated at a system level. It was found that for the given trailer dimensions, the voltage capability of test source is around 4 times higher in oil when compared to air, This shows the effectiveness of oil as an insulating medium. The feasibility of oil immersed converter design depends on the degree of compatibility of its components under oil. Hence, experimental investigation was conducted on Insulated Gate Bipolar Transistor modules (IGBT) under oil as they are considered to be a pivotal component in MMC. Preliminary results show the penetration of oil into the IGBT chip surface. Despite oil migration, the operation of IGBT was not hindered during the test. Based on the results obtained from experimental work, a road map of future tests is suggested that need to be performed to realize an oil immersed HV mobile test source.",
"author_names": [
"Getssy Prathiba Lourduraj"
],
"corpus_id": 208124060,
"doc_id": "208124060",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Feasibility study of oil immersed power electronic based high voltage test source for onsite testing purpose",
"venue": "",
"year": 2019
},
{
"abstract": "After a total blackout in its own area, each Transmission System Operator (TSO) has a responsibility to initiate a restoration process as quickly, safely and reliably as possible, re establishing the integrity of the electric power system (EPS) In recent years, this became topic on which the European Network of Transmission System Operators (ENTSO E) increased attention, requiring each TSO to establish and test appropriate restoration scenarios. In order to be able to restore the EPS safely and efficiently, it is necessary to verify the feasibility of a restoration scenario and be aware of the main issues during such a procedure. It is therefore important to develop testing models that should be able to simulate the behaviour of the EPS under various conditions. This master thesis presents a real time dynamic simulation of an EPS restoration procedure. In general, the thesis is split in two main parts. In the first part, an EPS is modelled for several restoration scenarios, implementing different re energization approaches. We considered several scenarios for the dynamic analysis, applying re energization of the transmission system by black start units or, with the help of neighbouring systems. In the second part of the thesis we focused on the operation of the re energized areas, in terms of synchronizing the re energized parts of the EPS, adding load to the system and maintaining the frequency. The simulations were carried out by specially designed computer system with a custom hardware and all in one software, Real Time Digital Simulator (RTDS) Using the RTDS device for restoration processes enables a wide range of simulations under various operating conditions, furthermore a possibility of testing a real physical power equipment operation during a black start procedure.",
"author_names": [
"Rajne Ilievska"
],
"corpus_id": 210963749,
"doc_id": "210963749",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Real time dynamic simulation of a power system restoration process",
"venue": "",
"year": 2019
}
] |
predictive maintenance in semiconductor etch tool | [
{
"abstract": "Increasing yield, eliminating unexpected downtime, and reducing maintenance costs are some of the potential benefits that a predictive monitoring system can provide for semiconductor manufacturing. Prior to the implementation of a predictive based condition monitoring approach for critical semiconductor equipment and components, the technology requires further development and validation. A systematic approach for developing a predictive monitoring system is presented, including several key steps that include data pre processing, feature extraction and selection, health assessment, and component lifetime prediction. The approach is demonstrated on a LAM 2300(r) Kiyo(r) conductor etch product, in which data was collected over an 8 month period from a GlobalFoundries Fab in Dresden, Germany. The methodology and predictive health models are demonstrated for an example component from the etching tool, the electrostatic chuck. Both trace signals and metrology data are evaluated for developing the health and prediction models for the electrostatic chuck. The health monitoring models provide a clear and increasing trend, in which the electrostatic health value can be tracked quite well over time. The systematic development framework shows promise and future works looks to further validate the prediction models, and in addition develop commercially viable implementation software from this work.",
"author_names": [
"Jay Lee",
"David Siegel",
"Edzel Lapira"
],
"corpus_id": 112415668,
"doc_id": "112415668",
"n_citations": 9,
"n_key_citations": 0,
"score": 1,
"title": "Development of a Predictive and Preventive Maintenance Demonstration System for a Semiconductor Etching Tool",
"venue": "",
"year": 2013
},
{
"abstract": "In modern semiconductor manufacturing facilities maintenance strategies are increasingly shifting from traditional preventive maintenance (PM) based approaches to more efficient and sustainable predictive maintenance (PdM) approaches. This paper describes the development of such an online PdM module for the endpoint detection system of an ion beam etch tool in semiconductor manufacturing. The developed system uses optical emission spectroscopy (OES) data from the endpoint detection system to estimate the RUL of lenses, a key detector component that degrades over time. Simulation studies for historical data for the use case demonstrate the effectiveness of the proposed PdM solution and the potential for improved sustainability that it affords.",
"author_names": [
"Jian Wan",
"Sean F McLoone",
"Patrick English",
"Paul G O'Hara",
"Adrian B Johnston"
],
"corpus_id": 107809304,
"doc_id": "107809304",
"n_citations": 6,
"n_key_citations": 0,
"score": 0,
"title": "Predictive Maintenance for Improved Sustainability An Ion Beam Etch Endpoint Detection System Use Case",
"venue": "",
"year": 2014
},
{
"abstract": "An adaptive neural network based advanced process control software, the Dynamic Neural Controller/spl trade/ (DNC) was employed at National Semiconductor's 200 mm fabrication facility, South Portland, Maine, to enhance the performance of metal etch tools. The installation was performed on 5 identical LAM 9600 TCP Metal etchers running production material. The DNC produced a single predictive model on critical outputs and metrology for each tool based on process variables, maintenance, input metrology and output metrology. Although process metrology is usually measured on only one wafer per lot, the process can be closely monitored on a wafer by wafer basis with the DNC models. The DNC was able to provide recommendations for maintenance (replacing components in advance of predicted failure) and process variable adjustments (e.g. gas flow) to maximize tool up time and to reduce scrap. This enabled the equipment engineers to both debug problems more quickly on the tool and to make adjustments to tool parameters before out of spec wafers were produced. After a comparison of the performance of all 5 tools for a 2 month period prior to DNC installation vs. a 2 month post DNC period, we concluded that the software was able to predict when maintenance actions were required, when process changes were required, and when maintenance actions were being taken but were not required. We observed a significant improvement in process C/sub pk/s for the metal etchers in this study.",
"author_names": [
"John M Hyde",
"Julie Doxsey",
"Jill P Card"
],
"corpus_id": 32140537,
"doc_id": "32140537",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "The use of unified APC/FD in the control of a metal etch area",
"venue": "2004 IEEE/SEMI Advanced Semiconductor Manufacturing Conference and Workshop (IEEE Cat. No.04CH37530)",
"year": 2004
},
{
"abstract": "In order to occupy a competitive position in semiconductor industry the most important challenges a fabrication plant has to face are the reduction of manufacturing costs and the increase of production yield. Predictive maintenance is one possible way to address these challenges. In this paper we present an implementation of a universally applicable methodology based on the theory of regression trees and Random Forests to predict tool maintenance operations. We exemplarily show the application of the method by constructing a model for predictive maintenance of an ion implantation tool. To fit the problem adequately and to allow a descriptive interpretation we introduce the remaining time until next maintenance as a response variable. By using R and adequately analyzing data acquired during wafer processing a Random Forest model is constructed. We can show that under typical production conditions the model is able to predict a recurring maintenance operation sufficiently accurate. This example shows that better planning of maintenance operations allows for an increase in productivity and a reduction of downtime costs.",
"author_names": [
"Peter Scheibelhofer",
"Dietmar Gleispach",
"Guenther Hayderer",
"Ernst Stadlober"
],
"corpus_id": 41940118,
"doc_id": "41940118",
"n_citations": 8,
"n_key_citations": 0,
"score": 0,
"title": "A Methodology for Predictive Maintenance in Semiconductor Manufacturing",
"venue": "",
"year": 2016
},
{
"abstract": "Over the past two years the Predictive Maintenance (PdM) capability in semiconductor manufacturing has migrated from Proof of Concept (PoC) and univariate Fault Detection (FD) extrapolation mechanisms to fab wide solutions that are (1) robust to typical process and equipment disturbances, (2) extensible so as to provide solution approaches that are portable across instances of a tool type and across tool types, and (3) maintainable so as to provide solutions that are useful for long periods of time. A number of advancements have facilitated this advancement including solutions for porting modeling components across process and equipment types, mechanisms for incorporating process and equipment knowledge into models, mechanisms for determining model context (e.g. recipe) dependency, methods for model optimization to fab financials, and methods for rejecting run time disturbances in PdM modeling. As a result of these and other innovations, the landscape of PdM in semiconductor manufacturing has rapidly advanced to the point that, from a technical perspective, solutions are now available for fab wide PdM realization.",
"author_names": [
"Jimmy Iskandar",
"James R Moyne",
"K Subrahmanyam",
"Parris C M Hawkins",
"Michael Armacost"
],
"corpus_id": 24080473,
"doc_id": "24080473",
"n_citations": 12,
"n_key_citations": 0,
"score": 0,
"title": "Predictive Maintenance in semiconductor manufacturing",
"venue": "2015 26th Annual SEMI Advanced Semiconductor Manufacturing Conference (ASMC)",
"year": 2015
},
{
"abstract": "Predictive maintenance is considered as one of the helpful techniques to improve the manufacturing process, especially in high mixed semiconductor manufacturing suffered from the frequent tool failing behavior. Prognostics is a good solution to infering the failing occurrence and realizing predictive maintenance. Because of the complicated and unclear tool failing phenomena, it is difficult to model the tool failing behavior by mechanism analysis. The difficulty impedes the development of prognostics in semiconductor manufacturing. As data driven methods aim at estimating future behaviors without knowledge of the underlying failing phenomena, this article proposes a novel data driven prognostic method based on auto associative Gaussian process regression to infer the tool failing behavior in semiconductor manufacturing. Through extracting the failing factors, determining the failing degree and constructing the prognostic model, the tool failing behavior tendency is predicted and the suitable chamber cleaning time is determined to improve the productivity and save the cost of semiconductor manufacturing. The effectiveness and practicality of the proposed method are demonstrated by a practical semiconductor manufacturing factory. The obtained prognostic results can help operators understand the tool failing behavior better and guide decision makers to make a suitable plan for chamber cleaning in semiconductor manufacturing.",
"author_names": [
"Li Zhu",
"Junghui Chen",
"Chun-I Chen"
],
"corpus_id": 215815782,
"doc_id": "215815782",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Prognostics of tool failing behavior based on autoassociative Gaussian process regression for semiconductor manufacturing",
"venue": "2020 IEEE International Conference on Industrial Technology (ICIT)",
"year": 2020
},
{
"abstract": "In this paper, an online predictive maintenance approach is proposed for monitoring health of semiconductor equipment. It includes two phases, the first is online prediction of the health indicator and the second phase is the classification of the indicator to one of the health states for making maintenance decisions. Kernel recursive least square (KRLS) algorithm is used for online prediction which is computational efficient. The health states of the equipment can be defined based on the requirement specification for the equipment maintenance. The classification is used in the second stage based on the prediction results come from the first stage. The approach is tested with a simulated dataset from a semiconductor tool and results show a relative high accuracy can be achieved with a satisfactory computational efficiency.",
"author_names": [
"Ming Luo",
"Zhao Xu",
"Hian-Leng Chan",
"Marjan Alavi"
],
"corpus_id": 25697909,
"doc_id": "25697909",
"n_citations": 6,
"n_key_citations": 1,
"score": 0,
"title": "Online predictive maintenance approach for semiconductor equipment",
"venue": "IECON 2013 39th Annual Conference of the IEEE Industrial Electronics Society",
"year": 2013
},
{
"abstract": "The unexpected failure of modern industrial systems is often managed using data driven predictive maintenance (PdM) tools that continuously monitor a system's health condition (HC) through raw sensor data to predict impending malfunction. However, research demonstrates that data driven PdM tools perform poorly when applied to raw multi sensor data, as it is not guaranteed that all sensor data describe a system's health condition. As systems become more complex and require multi sensor measurements, to perform accurate data driven PdM, an accurate health condition representation of a system's life cycle data is required. This work introduces a Kullback Leibler divergence (KLD) based health indicator (HI) constructor for multi sensor systems. This method applies information entropy to construct a HI representation that describes the occurrence of faults and their influences during a system's life cycle. Additionally, the proposed method conducts feature selection to expose and remove sensors that do not capture information related to a system's HC. The utility of the proposed method is tested on the Commercial Modular Aero Propulsion System Simulation turbofan engine data and the OEM Group's Cintillio SAT Batch Spray semiconductor manufacturing equipment data.",
"author_names": [
"Oluseun Omotola Aremu",
"Darren O O'Reilly",
"David Hyland-Wood",
"Peter Ross McAree"
],
"corpus_id": 195484900,
"doc_id": "195484900",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Kullback Leibler Divergence Constructed Health Indicator for Data Driven Predictive Maintenance of Multi Sensor Systems",
"venue": "2019 IEEE 17th International Conference on Industrial Informatics (INDIN)",
"year": 2019
},
{
"abstract": "In this paper an approach to deal with Predictive Maintenance (PdM) problems with time series data is discussed. PdM is a important approach to tackle maintenance and it is gaining an increasing attention in advanced manufacturing to minimize scrap materials, downtime, and associated costs. PdM approaches are generally based on Machine Learning tools that require the availability of historical process and maintenance data. Given the exponential growth in data logging in modern equipment, time series dataset are increasingly available in PdM applications. To exploit time series data for PdM, a functional learning methodology, namely Supervised Aggregative Feature Extraction (SAFE) is here employed on a semiconductor manufacturing maintenance problem.",
"author_names": [
"Gian Antonio Susto",
"Alessandro Beghi"
],
"corpus_id": 1327737,
"doc_id": "1327737",
"n_citations": 23,
"n_key_citations": 0,
"score": 0,
"title": "Dealing with time series data in Predictive Maintenance problems",
"venue": "2016 IEEE 21st International Conference on Emerging Technologies and Factory Automation (ETFA)",
"year": 2016
},
{
"abstract": "Ion Implantation is one of the most sensitive processes in Semiconductor Manufacturing. It consists in impacting accelerated ions with a material substrate and is performed by an Implanter tool. The major maintenance issue of such tool concerns the breaking of the tungsten filament contained within the ion source of the tool. This kind of fault can happen on a weekly basis, and the associated maintenance operations can last up to 3 hours. It is important to optimize the maintenance activities by synchronizing the Filament change operations with other minor maintenance interventions. In this paper, a Predictive Maintenance (PdM) system is proposed to tackle such issue; the filament lifetime is estimated on a statistical basis exploiting the knowledge of physical variables acting on the process. Given the high dimensionality of the data, the statistical modeling has been based on Regularization Methods: Lasso, Ridge Regression and Elastic Nets. The predictive performances of the aforementioned regularization methods and of the proposed PdM module have been tested on actual productive semiconductor data.",
"author_names": [
"Gian Antonio Susto",
"Andrea Schirru",
"Simone Pampuri",
"Alessandro Beghi"
],
"corpus_id": 25387610,
"doc_id": "25387610",
"n_citations": 21,
"n_key_citations": 4,
"score": 0,
"title": "A predictive maintenance system based on regularization methods for ion implantation",
"venue": "2012 SEMI Advanced Semiconductor Manufacturing Conference",
"year": 2012
}
] |
Nitride semiconductor devices principles and simulation | [
{
"abstract": "Preface. List of Contributors. Part 1 Material Properties. 1 Introduction (Joachim Piprek) 1.1 A Brief History. 1.2 Unique Material Properties. 1.3 Thermal Parameters. References. 2 Electron Bandstructure Parameters (Igor Vurgaftman and Jerry R. Meyer) 2.1 Introduction. 2.2 Band Structure Models. 2.3 Band Parameters. 2.4 Conclusions. References. 3 Spontaneous and Piezoelectric Polarization: Basic Theory vs. Practical Recipes (Fabio Bernardini) 3.1 Why Spontaneous Polarization in III V Nitrides? 3.2 Theoretical Prediction of Polarization Properties in AlN, GaN and InN. 3.3 Piezoelectric and Pyroelectric Effects in III V Nitrides Nanostructures. 3.4 Polarization Properties in Ternary and Quaternary Alloys. 3.5 Orientational Dependence of Polarization. References. 4 Transport Parameters for Electrons and Holes (Enrico Bellotti and Francesco Bertazzi) 4.1 Introduction. 4.2 Numerical Simulation Model. 4.3 Analytical Models for the Transport Parameters. 4.4 GaN Transport Parameters. 4.5 AlN Transport Parameters. 4.6 InN Transport Parameters. 4.7 Conclusions. References. 5 Optical Constants of Bulk Nitrides (Rudiger Goldhahn, Carsten Buchheim, Pascal Schley, Andreas Theo Winzer, and Hans Wenzel) 5.1 Introduction. 5.2 Dielectric Function and Band Structure. 5.3 Experimental Results. 5.4 Modeling of the Dielectric Function. References. 6 Intersubband Absorption in AlGaN/GaN Quantum Wells (Sulakshana Gunna, Francesco Bertazzi, Roberto Paiella, and Enrico Bellotti) 6.1 Introduction. 6.2 Theoretical Model. 6.3 Numerical Implementation. 6.4 Absorption Energy in AlGaN GaN MQWs. 6.5 Conclusions. References. 7 Interband Transitions in InGaN Quantum Wells (Jorg Hader, Jerome V. Moloney, Angela Thranhardt, and Stephan W. Koch) 7.1 Introduction. 7.2 Theory. 7.3 Theory Experiment Gain Comparison. 7.4 Absorption/Gain. 7.5 Spontaneous Emission. 7.6 Auger Recombinations. 7.7 Internal Field Effects. 7.8 Summary. References. 8 Electronic and Optical Properties of GaN based Quantum Wells with (1010) Crystal Orientation (Seoung Hwan Park and Shun Lien Chuang) 8.1 Introduction. 8.2 Theory. 8.2.1 Non Markovian gain model with many body effects. 8.3 Results and Discussion. 8.4 Summary. References. 9 Carrier Scattering in Quantum Dot Systems (Frank Jahnke) 9.1 Introduction. 9.2 Scattering Due to Carrier Carrier Coulomb Interaction. 9.3 Scattering Due to Carrier Phonon Interaction. 9.4 Summary and Outlook. References. Part 2 Devices. 10 AlGaN/GaN High Electron Mobility Transistors (Tomas Palacios and Umesh K. Mishra) 10.1 Introduction. 10.2 Physics based Simulations. 10.3 Conclusions. References. 11 Intersubband Optical Switches for Optical Communications (Nobuo Suzuki) 11.1 Introduction. 11.2 Physics of ISBT in Nitride MQWs. 11.3 Calculation of Absorption Spectra. 11.4 FDTD Simulator for GaN/AlGaN ISBT Switches. References. 12 Intersubband Electroabsorption Modulator (Petter Holmstrom) 12.1 Introduction. 12.2 Modulator Structure. 12.3 Model. 12.4 Results. 12.5 Summary. References. 13 Ultraviolet Light Emitting Diodes (Yen Kuang Kuo, Sheng Horng Yen, and Jun Rong Chen) 13.1 Introduction. 13.2 Device Structure. 13.3 Physical Models and Parameters. 13.4 Comparison Between Simulated and Experimental Results. 13.5 Performance Optimization. 13.6 Conclusion. References. 14 Visible Light Emitting Diodes (Sergey Yu. Karpov) 14.1 Introduction. 14.2 Simulation Approach and Materials Properties. 14.3 Device Analysis. 14.4 Novel LED Structures. 14.5 Conclusion. References. 15 Simulation of LEDs with Phosphorescent Media for the Generation of White Light (Norbert Linder, Dominik Eisert, Frank Jermann, and Dirk Berben) 15.1 Introduction. 15.2 Requirements for a Conversion LED Model. 15.3 Color Metrics for Conversion LEDs. 15.4 Phosphor Model. 15.5 Simulation Examples. 15.6 Conclusions. References. 16 Fundamental Characteristics of Edge Emitting Lasers (Gen ichi Hatakoshi) 16.1 Introduction. 16.2 Basic Equations for the Device Simulation. 16.3 Simulation for Electrical Characteristics and Carrier Overflow Analysis. 16.4 Perpendicular TransverseMode and Beam Quality Analysis. 16.5 Thermal Analysis. 16.6 Conclusions. References. 17 Resonant Internal Transverse Mode Coupling in InGaN/GaN/AlGaN Lasers (Gennady A. Smolyakov and Marek Osinski) 17.1 Introduction. 17.2 Internal Mode Coupling and the Concept of \"Ghost Modes.\" 17.3 Device Structure and Material Parameters. 17.4 Calculation Technique. 17.5 Results of Calculations. 17.6 Discussion and Conclusions. References. 18 Optical Properties of Edge Emitting Lasers: Measurement and Simulation (Ulrich T. Schwarz and Bernd Witzigmann) 18.1 Introduction. 18.2 Waveguide Mode Stability. 18.3 Optical Waveguide Loss. 18.4 Mode Gain Analysis. 18.5 Conclusion. References. 19 Electronic Properties of InGaN/GaN Vertical Cavity Lasers (Joachim Piprek, Zhan Ming Li, Robert Farrell, Steven P. DenBaars, and Shuji Nakamura) 19.1 Introduction to Vertical Cavity Lasers. 19.2 GaN based VCSEL Structure. 19.3 Theoretical Models and Material Parameters. 19.4 Simulation Results and Device Analysis. 19.5 Summary. References. 20 Optical Design of Vertical Cavity Lasers (Wlodzimierz Nakwaski, Tomasz Czyszanowski, and Robert P. Sarzala) 20.1 Introduction. 20.2 The GaN VCSEL Structure. 20.3 The Scalar Optical Approach. 20.4 The Vectorial Optical Approach. 20.5 The Self consistent Calculation Algorithm. 20.6 Simulation Results. 20.7 Discussion and Conclusions. References. 21 GaN Nanowire Lasers (Alexey V. Maslov and Cun Zheng Ning) 21.1 Introduction. 21.2 Nanowire Growth and Characterization. 21.3 Nanowire Laser Principles. 21.4 Anisotropy of Material Gain. 21.5 Guided Modes. 21.6 Modal Gain and Threshold. 21.7 Conclusion. References. Index.",
"author_names": [
"Joachim Piprek"
],
"corpus_id": 92639736,
"doc_id": "92639736",
"n_citations": 431,
"n_key_citations": 15,
"score": 1,
"title": "Nitride semiconductor devices principles and simulation",
"venue": "",
"year": 2007
},
{
"abstract": "Bulk gallium nitride (GaN) power semiconductor devices are gaining significant interest in recent years, creating the need for technology computer aided design (TCAD) simulation to accurately model and optimize these devices. This paper comprehensively reviews and compares different GaN physical models and model parameters in the literature, and discusses the appropriate selection of these models and parameters for TCAD simulation. 2 D drift diffusion semi classical simulation is carried out for 2.6 kV and 3.7 kV bulk GaN vertical PN diodes. The simulated forward current voltage and reverse breakdown characteristics are in good agreement with the measurement data even over a wide temperature range.",
"author_names": [
"Gourab Sabui",
"Peter J Parbrook",
"Miryam Arredondo-Arechavala",
"Z John Shen"
],
"corpus_id": 55278684,
"doc_id": "55278684",
"n_citations": 32,
"n_key_citations": 0,
"score": 0,
"title": "Modeling and simulation of bulk gallium nitride power semiconductor devices",
"venue": "",
"year": 2016
},
{
"abstract": "1. Introduction. 1.1 The Goal of Modeling. 1.2 The History of Numerical Device Modeling. 1.3 References. 2. Some Fundamental Properties. 2.1 Poisson's Equation. 2.2 Continuity Equations. 2.3 Carrier Transport Equations. 2.4 Carrier Concentrations. 2.5 Heat Flow Equation. 2.6 The Basic Semiconductor Equations. 2.7 References. 3. Proeess Modeling. 3.1 Ion Implantation. 3.2 Diffusion. 3.3 Oxidation. 3.4 References. 4. The Physical Parameters. 4.1 Carrier Mobility Modeling. 4.2 Carrier Generation Recombination Modeling. 4.3 Thermal Conductivity Modeling. 4.4 Thermal Generation Modeling. 4.5 References. 5. Analytical Investigations About the Basic Semiconductor Equations. 5.1 Domain and Boundary Conditions. 5.2 Dependent Variables. 5.3 The Existence of Solutions. 5.4 Uniqueness or Non Uniqueness of Solutions. 5.5 Sealing. 5.6 The Singular Perturbation Approach. 5.7 Referenees. 6. The Diseretization of the Basic Semiconductor Equations. 6.1 Finite Differences. 6.2 Finite Boxes. 6.3 Finite Elements. 6.4 The Transient Problem. 6.5 Designing a Mesh. 6.6 Referenees. 7. The Solution of Systems of Nonlinear Algebraic Equations. 7.1 Newton's Method and Extensions. 7.2 Iterative Methods. 7.3 Referenees. 8. The Solution of Sparse Systems of Linear Equations. 8.1 Direct Methods. 8.2 Ordering Methods. 8.3 Relaxation Methods. 8.4 Alternating Direction Methods. 8.5 Strongly Implicit Methods. 8.6 Convergence Acceleration of Iterative Methods. 8.7 Referenees. 9. A Glimpse on Results. 9.1 Breakdown Phenomena in MOSFET's. 9.2 The Rate Effect in Thyristors. 9.3 Referenees. Author Index. Table Index.",
"author_names": [
"Siegfried Selberherr"
],
"corpus_id": 118958966,
"doc_id": "118958966",
"n_citations": 2507,
"n_key_citations": 151,
"score": 0,
"title": "Analysis and simulation of semiconductor devices",
"venue": "",
"year": 1984
},
{
"abstract": "3",
"author_names": [
"Martin Lades"
],
"corpus_id": 107268524,
"doc_id": "107268524",
"n_citations": 33,
"n_key_citations": 3,
"score": 0,
"title": "Modeling and Simulation of Wide Bandgap Semiconductor Devices: 4H/6H SiC",
"venue": "",
"year": 2000
},
{
"abstract": "This paper focuses on providing an improved and efficient alternative to electromechanical relays (EMRs) in view of the growing demand characteristics for an effective power multiplexing in induction heating applications. A major analytical approach to the design and implementation of bidirectional switches (BDSs) based on different power semiconductor technologies is presented, including thorough static and dynamic characterizations. Emerging gallium nitride high electron mobility transistors (GaN HEMTs) and silicon carbide (SiC) based devices are identified as potential candidates for the mentioned applications.",
"author_names": [
"Manuel Fernandez",
"Xavier Perpina",
"Jose Rebollo",
"Miquel Vellvehi",
"David Sanchez",
"Tomas Cabeza",
"Sergio Llorente",
"Xavier Jorda"
],
"corpus_id": 53239423,
"doc_id": "53239423",
"n_citations": 8,
"n_key_citations": 0,
"score": 0,
"title": "Solid State Relay Solutions for Induction Cooking Applications Based on Advanced Power Semiconductor Devices",
"venue": "IEEE Transactions on Industrial Electronics",
"year": 2019
},
{
"abstract": "We propose a two dimensional (2D) tetragonal material: an yttrium nitride (t YN) monolayer, with a distinguished combination of mechanical and electronic properties based on first principles calculations. We find that the t YN monolayer is a low direct band gap semiconductor (0.55 eV) with strong anisotropic mechanical and electronic properties. We also identify that the t YN monolayer to be a 2D ferroelastic material with a reversible strain of about 14.4% indicating that the anisotropic properties of the t YN monolayer can be switched by applying external stress. Furthermore, the moderate switching barrier (33 meV/atom) of ferroelastic lattice rotation renders the switchable anisotropic properties accessible experimentally. These outstanding properties make the t YN monolayer a promising switchable anisotropic 2D material for electronic and mechanical applications.",
"author_names": [
"Bo Xu",
"H Xiang",
"Jiang Yin",
"Yidong Xia",
"Zhiguo Liu"
],
"corpus_id": 206106400,
"doc_id": "206106400",
"n_citations": 32,
"n_key_citations": 1,
"score": 0,
"title": "A two dimensional tetragonal yttrium nitride monolayer: a ferroelastic semiconductor with switchable anisotropic properties.",
"venue": "Nanoscale",
"year": 2017
},
{
"abstract": "Gallium nitride (GaN) based High Electron Mobility Transistors (HEMTs) are candidates for the next generation of power electronic devices and are therefore subject of intense research activities worldwide. Technology CAD (TCAD) has proven a major impact on the optimization of silicon based device technologies. It is a logical follow up to provide accurate simulation tools, methods and models for GaN based device technologies that are benchmarked against hardware data. This work presents a systematic investigation of GaN HEMTs by TCAD, including process emulation, in plane and full stress simulation, and drift diffusion device simulation.",
"author_names": [
"Stephan Strauss",
"A Erlebach",
"Tommaso Cilento",
"Denis Marcon",
"Steve Stoffels",
"Benoit Bakeroot"
],
"corpus_id": 19433457,
"doc_id": "19433457",
"n_citations": 26,
"n_key_citations": 1,
"score": 0,
"title": "TCAD methodology for simulation of GaN HEMT power devices",
"venue": "2014 IEEE 26th International Symposium on Power Semiconductor Devices IC's (ISPSD)",
"year": 2014
},
{
"abstract": "Design and training principles have been proposed and tested for an artificial neural network based on metal oxide thin film nanostructures possessing bipolar resistive switching (memristive) effect. Experimental electronic circuit of neural network is implemented as a double layer perceptron with a weight matrix composed of 32 memristive devices. The network training algorithm takes into account technological variations of the parameters of memristive devices. Despite the limited size of weight matrix the developed neural network model is scalable and capable of solving nonlinear classification problems. The learning and functionality of the network are demonstrated by using its computer model for the classification of activity propagation directions in simulated neuronal culture.",
"author_names": [
"Alexey N Mikhaylov",
"Oleg A Morozov",
"Pavel E Ovchinnikov",
"Ivan N Antonov",
"Alexey I Belov",
"Dmitry S Korolev",
"Alexander N Sharapov",
"Evgeniy G Gryaznov",
"Oleg N Gorshkov",
"Yana Pigareva",
"Alexey S Pimashkin",
"Sergey A Lobov",
"Victor B Kazantsev"
],
"corpus_id": 52893161,
"doc_id": "52893161",
"n_citations": 23,
"n_key_citations": 1,
"score": 0,
"title": "One Board Design and Simulation of Double Layer Perceptron Based on Metal Oxide Memristive Nanostructures",
"venue": "IEEE Transactions on Emerging Topics in Computational Intelligence",
"year": 2018
},
{
"abstract": "Gallium nitride (GaN) is a compound semiconductor that has tremendous potential to facilitate economic growth in a semiconductor industry that is silicon based and currently faced with diminishing returns of performance versus cost of investment. At a material level, its high electric field strength and electron mobility have already shown tremendous potential for high frequency communications and photonic applications. Advances in growth on commercially viable large area substrates are now at the point where power conversion applications of GaN are at the cusp of commercialisation. The future for building on the work described here in ways driven by specific challenges emerging from entirely new markets and applications is very exciting. This collection of GaN technology developments is therefore not itself a road map but a valuable collection of global state of the art GaN research that will inform the next phase of the technology as market driven requirements evolve. First generation production devices are igniting large new markets and applications that can only be achieved using the advantages of higher speed, low specific resistivity and low saturation switching transistors. Major investments are being made by industrial companies in a wide variety of markets exploring the use of the technology in new circuit topologies, packaging solutions and system architectures that are required to achieve and optimise the system advantages offered by GaN transistors. It is this momentum that will drive priorities for the next stages of device research gathered here.",
"author_names": [
"Hiroshi Amano",
"Y Baines",
"Matteo Borga",
"T Bouchet",
"Paul R Chalker",
"Matthew Charles",
"K J Chen",
"Nadim Chowdhury",
"Rongming Chu",
"Carlo De Santi",
"Maria Merlyne De Souza",
"Stefaan Decoutere",
"Lea Di Cioccio",
"Bernd Eckardt",
"Takashi Egawa",
"Patrick J Fay",
"Joseph J Freedsman",
"Louis Guido",
"Oliver Haberlen",
"Geoff Haynes",
"Thomas Heckel",
"Dilini Hemakumara",
"Peter A Houston",
"Jie Hu",
"Mengyuan Hua",
"Qingyun Huang",
"Alex Q Huang",
"Sheng Jiang",
"Hiroji Kawai",
"Daniel M Kinzer",
"Martin Kuball",
"Ashwani Kumar",
"Kean Boon Lee",
"Xu Li",
"Denis Marcon",
"Martin Marz",
"Robert McCarthy",
"Gaudenzio Meneghesso",
"Matteo Meneghini",
"Erwan Morvan",
"Akira Nakajima",
"E M Sankara Narayanan",
"Stephen Oliver",
"Tomas Palacios",
"Daniel Piedra",
"Marc Plissonnier",
"Rekha Reddy",
"Min-Chul Sun",
"Iain G Thayne",
"A Torres",
"Nicola Trivellin",
"Vineet Unni",
"Michael J Uren",
"Marleen Van Hove",
"David J Wallis",
"Jingshan Wang",
"Jinqiao Xie",
"Shuichi Yagi",
"Shu Yun Yang",
"C Youtsey",
"Ruiyang Yu",
"Enrico Zanoni",
"Stefan Zeltner",
"Yuhao Zhang"
],
"corpus_id": 4714529,
"doc_id": "4714529",
"n_citations": 426,
"n_key_citations": 4,
"score": 0,
"title": "The 2018 GaN power electronics roadmap",
"venue": "",
"year": 2018
},
{
"abstract": "Hexagonal boron nitride (h BN) and semiconducting transition metal dichalcogenides (TMDs) promise greatly improved electrostatic control in future scaled electronic devices. To quantify the prospects of these materials in devices, we calculate the out of plane and in plane dielectric constant from first principles for TMDs in trigonal prismatic and octahedral coordination, as well as for h BN, with a thickness ranging from monolayer and bilayer to bulk. Both the ionic and electronic contribution to the dielectric response are computed. Our calculations show that the out of plane dielectric response for the transition metal dichalcogenides is dominated by its electronic component and that the dielectric constant increases with increasing chalcogen atomic number. Overall, the out of plane dielectric constant of the TMDs and h BN increases by around 15% as the number of layers is increased from monolayer to bulk, while the in plane component remains unchanged. Our computations also reveal that for octahedrally coordinated TMDs the ionic (static) contribution to the dielectric response is very high (4.5 times the electronic contribution) in the in plane direction. This indicates that semiconducting TMDs in the tetragonal phase will suffer from excessive polar optical scattering thereby deteriorating their electronic transport properties.Optical properties: in plane and out of plane dielectric constants of 2D semiconductorsThe out of plane dielectric constant of transition metal dichalcogenides and h BN is thickness dependent, unlike their in plane counterpart. A team led by William Vandenberghe at the University of Texas at Dallas performed calculations of the optical and static relative permittivity of free standing monolayer, bilayer, and bulk transition metal dichalcogenides, in the in plane and out of plane directions. In h BN, the in plane contribution was found to be larger than its out of plane counterpart, and independent on the number of h BN layers. Conversely, the out of plane h BN dielectric constant showed an increase when going from monolayer to bulk. In transition metal dichalcogenides, the dielectric constant components displayed similar trends to those observed in h BN with regards to their thickness evolution. The calculations also indicated that the electronic component dominates the overall dielectric response for most of the analyzed 2D materials.",
"author_names": [
"Akash A Laturia",
"Maarten L Van de Put",
"William G Vandenberghe"
],
"corpus_id": 139684607,
"doc_id": "139684607",
"n_citations": 265,
"n_key_citations": 3,
"score": 0,
"title": "Dielectric properties of hexagonal boron nitride and transition metal dichalcogenides: from monolayer to bulk",
"venue": "npj 2D Materials and Applications",
"year": 2018
}
] |
tunneling field transistor | [
{
"abstract": "With the development of semiconductor technology, the size of traditional metal oxide semiconductor field effect transistor devices continues to decrease, but it cannot meet the requirements of high performance and low power consumption. Low power tunneling field effect transistor (TFET) has gradually become the focus of researchers. This paper proposes a novel T shaped gate TFET based on the silicon with the negative capacitance (NC TGTFET) On the basis of TGTFET, ferroelectric material (HZO) is used as gate dielectric. The simulation results show that, compared with the traditional TGTFET, the opening order and sensitivity of the two tunneling junctions are different. The influences of thickness and the doping concentration of pocket and ferroelectric material properties on the characteristics of NC TGTFET is also discussed by Sentaurus simulation tool. Furthermore, the negative capacitance of ferroelectric material makes NC TGTFET have a very steep subthreshold swing (18.32 mV/dec) at the range of drain current from 1 x 10 15 to 1 x 10 7 A mm 1. And the on state current (V g 0.5 V, V d 0.5 V) is 1.52 x 10 6 A mm 1.",
"author_names": [
"Qingrui Jia",
"Yumei Pan",
"Yue Yin",
"Yupan Wu",
"Yucheng Wang",
"Yi Wen",
"Shaoxi Wang"
],
"corpus_id": 235595816,
"doc_id": "235595816",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "A T shaped gate tunneling field effect transistor with negative capacitance, super steep subthreshold swing",
"venue": "Nanotechnology",
"year": 2021
},
{
"abstract": "It has been experimentally shown that metallic zigzag graphene nanoribbon (ZGNR) can be obtained by unzipping a carbon nanotube (CNT) along the chiral direction of CNT. This makes it possible to fabricate a unique AGNR ZGNR CNT heterojunction so that the semi metallic ZGNR is between semiconducting AGNR and CNT. Here we demonstrate that such a unique all carbon heterojunction may be utilized to obtain a barrier free tunneling field effect transistor (TFET) By performing a self consistent first principle calculation based on density functional theory combined with none equilibrium Green's function (DFT NEGF) we show that such a barrier free TFET may reduce subthreshold swing below the classical limit while increase on state current by diminishing tunneling barrier, which provides an promising route toward ultralow power, highperformance carbon heterojunction electronics.",
"author_names": [
"Yu Zhu",
"Wenli Zhou",
"Qingfeng Gong"
],
"corpus_id": 234478832,
"doc_id": "234478832",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Enhanced On state Current in Barrier free Carbon Heterojunction Tunneling Field effect Transistor",
"venue": "2021 5th IEEE Electron Devices Technology Manufacturing Conference (EDTM)",
"year": 2021
},
{
"abstract": "Abstract Tunneling field effect transistors (TFETs) have emerged as a potential candidate to outperform conventional metal oxide semiconductor FETs at low voltages, since their operation mechanism can overcome the fundamental subthreshold swing (SS) limit of 60 mV/decade at room temperature. We report carbon nanotube (CNT) based TFETs with abrupt p i n tunneling junctions controlled by electrostatic doping. Minimum SS (SSmin) of ~41 mV/dec is observed with nearly no temperature dependence, as clear evidence of the TFET operation. We further investigate devices using CNTs with smaller bandgaps, reporting a record high band to band tunneling (BTBT) current of ~100 nA for a single CNT. Non linear output characteristics are observed as expected for devices operating outside of the quantum capacitance limit (QCL) Overall, electrostatically doped CNT TFETs shine a promising path for low power electronic applications.",
"author_names": [
"Chin-Sheng Pang",
"Shu-Jen Han",
"Zhihong Chen"
],
"corpus_id": 235514858,
"doc_id": "235514858",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Steep slope carbon nanotube tunneling field effect transistor",
"venue": "",
"year": 2021
},
{
"abstract": "In this work, a new simulation approach of transient analysis on single cavity dielectric modulated (DM) <inline formula> <tex math notation=\"LaTeX\"{p} /tex math>/inline formula> type of tunnel field effect transistor (TFET) is examined for biosensing applications. The device operation and performance are investigated using the 2D device simulator and results are well calibrated with experimental data. In this work, we have examined DC transfer characteristics, the transient response of drain current, drain current sensitivity <inline formula> <tex math notation=\"LaTeX\"{S} /tex math>/inline formula> and selectivity <inline formula> <tex math notation=\"LaTeX\"\\Delta {S} /tex math>/inline formula> Focussing more on the transient results, we have obtained maximum sensitivity of orders greater than 10<sup>8</sup> for APTES biomolecule with respect to air and a significant selectivity value in orders of 10<sup>3</sup> for APTES with respect to Biotin biomolecule. The performance of the device in terms of selectivity can be further improved ~10<sup>4</sup> by optimizing the back gate bias, and therefore, the impact of back gate bias has been analysed. The results for charged biomolecules and partially filled cavity are further investigated highlighted. The DM <inline formula> <tex math notation=\"LaTeX\"{p} /tex math>/inline formula> TFET biosensor shows a significant improvement in the results with the transient response for biosensing applications with the feasibility of operating at low voltages (gate voltage of 2.0 V, drain voltage of 0.5 V and back gate voltage 0 to 0.5 V)",
"author_names": [
"Praveen Dwivedi",
"Rohit Singh",
"Brajendra Singh Sengar",
"Amitesh Kumar",
"Vivek Garg"
],
"corpus_id": 226602443,
"doc_id": "226602443",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "A New Simulation Approach of Transient Response to Enhance the Selectivity and Sensitivity in Tunneling Field Effect Transistor Based Biosensor",
"venue": "IEEE Sensors Journal",
"year": 2021
},
{
"abstract": "",
"author_names": [
"Mina Mazrouei",
"Daryoosh Dideban",
"Hamed Jooypa"
],
"corpus_id": 235562415,
"doc_id": "235562415",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Reducing Ambipolar Conduction in a Graphene Tunneling Field Effect Transistor (GTFET) via Bandgap Engineering",
"venue": "",
"year": 2021
},
{
"abstract": "",
"author_names": [
"Guenifi Naima",
"Dr Shiromani Balmukund Rahi"
],
"corpus_id": 233657006,
"doc_id": "233657006",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Design and Optimization of Heterostructure Double Gate Tunneling Field Effect Transistor for Ultra Low Power Circuit and System",
"venue": "",
"year": 2021
},
{
"abstract": "",
"author_names": [
"Simhadri Hariprasad",
"Surya Shankar Dan",
"Ramakant Yadav",
"A Mishra"
],
"corpus_id": 233532020,
"doc_id": "233532020",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Double gate line tunneling field effect transistor devices for superior analog performance",
"venue": "Int. J. Circuit Theory Appl.",
"year": 2021
},
{
"abstract": "GaXIn1 XAs/GaYIn1 YSb vertical heterojunctionless tunneling field effect transistor (VHJL TFET) has been suggested to optimize the digital benchmarking parameters. In the proposed VHJL TFET with type II heterostructure (i.e. X=0.8, Y=0.85) slight changes in gate voltage cause switching from OFF state to ON state. As a result, the electrical properties of Ga0.8In0.2As/Ga0.85In0.15Sb VHJL TFET are excellent in the sub threshold region. The heterostructure with III V semiconductors in the source channel region increases the ON state current (ION (of the VHJL TFET. Comparing the results of Ga0.8In0.2As/Ga0.85In0.15Sb VHJL TFET with the simulated devices with type I heterostructure (i.e. X=0.9, Y=0.1) and type III heterostructure (i.e. X=0.1, Y=0.4) shows the improvement by 26% and 15% in the average subthreshold slope (SS) Sensitivity analysis for VHJL TFET with the type II heterostructure shows that the sensitivity of OFF state current (IOFF) to the body thickness (Tb) and doping concentration (ND) is more than the sensitivity of the other main electrical parameters. The Ga0.8In0.2As/Ga0.85In0.15Sb VHJL TFET with a channel length of 20 nm, Tb=5 nm, and ND=1x1018cm 3 showed the SS=4.4mV/dec, ION/IOFF=4E14, and ION=8mA/um. As a result, Ga0.8In0.2As/Ga0.85In0.15Sb VHJL TFET can be a reasonable choice for digital applications.",
"author_names": [
"Behzad Rajabi",
"Mahdi Vadizadeh"
],
"corpus_id": 233609054,
"doc_id": "233609054",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Investigation of the impact of mole fraction on the digital benchmarking parameters as well as sensitivity in GaXIn1 XAs/GaYIn1 YSb vertical heterojunctionless tunneling field effect transistor",
"venue": "",
"year": 2021
},
{
"abstract": "Abstract Overcoming the performance limits encountered with the conventional nanoscale transistors while simplifying the fabrication process is an objective that can give a new impulses to the modern nanoelectronics. A novel band to band tunneling junctionless carbon nanotube field effect transistor, endowed with a lightly doped pocket underneath the coaxial gate, is computationally proposed herein. The quantum simulation based on the non equilibrium Green's function formalism is used in the investigation while considering the self consistent electrostatics and ballistic transport conditions. The proposed nanodevice switches via the modulation of band to band tunneling in the absence of thermionic emission mechanism. The pocket induced barrier is employed to mitigate the ambiploar behavior attributed to the thermionic current and to improve the nanodevice performance. The simulations show that the proposed device exhibits improved leakage current, ambipolar behavior, subthermionic subthreshold swing, and current ratio in comparison to those provided by its conventional counterpart uniformly doped. In addition, the role of the pocket length in boosting the performance of the proposed band to band tunneling device is investigated, where the optimal length of lightly doped pocket is revealed. Note that the obtained enhancements have been thoroughly analyzed using the energy position resolved charge density and current spectrum. The recorded improvements, namely subthermionic subthreshold swing and high ION/IOFF current ratio, together with the merits of junctionless paradigm, make the proposed pocket based technique, as an intriguing strategy that can be used to boost the performance of similar nanoscale band to band tunneling junctionless field effect transistors for high performance and low power applications.",
"author_names": [
"Khalil Tamersit"
],
"corpus_id": 233072495,
"doc_id": "233072495",
"n_citations": 4,
"n_key_citations": 0,
"score": 1,
"title": "A novel band to band tunneling junctionless carbon nanotube field effect transistor with lightly doped pocket: Proposal, assessment, and quantum transport analysis",
"venue": "",
"year": 2021
},
{
"abstract": "Abstract In here, a new structure based on doping less tunneling CNTFET is introduced. The CNT semiconductor is intrinsic throughout and selected for the source and drain regions of metals with appropriate work functions. The whole process of importing doping is eliminated, and the source and drain regions are created only by applying two metals with different work functions. The drain metal work function is 1 eV lower and those of source, is 1 eV higher than the CNT work function. The simulation is performed in the ballistic regime by solving the Poisson and Schrodinger equations in a self consistent way using the non equilibrium Green's function method. The results show that the proposed structure widens the barrier on the drain channel connection and consequently improves the band to band tunneling and the ambipolar behavior of the device. Also, the proposed structure reduces the OFF state current, increases the current ratio and decreases the subthreshold swing.",
"author_names": [
"Maryam Ghodrati",
"Ali Mir",
"Ali Naderi"
],
"corpus_id": 233823853,
"doc_id": "233823853",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Proposal of a doping less tunneling carbon nanotube field effect transistor",
"venue": "",
"year": 2021
}
] |
three level converter t design | [
{
"abstract": "Although the maximum collector emitter voltage of a high voltage insulated gate bipolar transistor (HV IGBT) reaches 3300 V or higher, it still cannot satisfy the requirements of some high voltage high power converters. Applying power semiconductor devices in series connection can effectively improve the voltage rating and power rating of a power electronic converter. The key issue of device series connection is voltage balancing in static switching state and dynamic switching state. In this paper, a three level converter based on series connected HV IGBTs is presented, its voltage balancing subcircuits are analyzed, and the parameter design method for the converter is proposed. During the design process, key performance indexes of the series connection circuit, such as the voltage balancing effect, loss of the voltage balancing circuit, switching loss, and switching time, are comprehensively considered. Moreover, component parameters of the three level converter are calculated considering the influence of the voltage balancing circuit. The proposed parameter design method is applied in the development of a three level HV IGBT (4500 V/600 A) series connection test platform with 10 000 V rated dc link voltage. Experimental results verify the validity of the proposed method.",
"author_names": [
"Ting Lu",
"Zhengming Zhao",
"Hualong Yu",
"Shiqi Ji",
"Liqiang Yuan",
"Fanbo He"
],
"corpus_id": 17059298,
"doc_id": "17059298",
"n_citations": 12,
"n_key_citations": 0,
"score": 0,
"title": "Parameter Design of a Three Level Converter Based on Series Connected HV IGBTs",
"venue": "IEEE Transactions on Industry Applications",
"year": 2014
},
{
"abstract": "This paper presents the design and analysis of a three level hybrid boost converter based on a single phase three level T type inverter. The proposed converter can provide high energy conversion efficiency and high voltage gain capability with reduced component count. The pulse width modulation signals of the proposed converter are generated by comparing two duty cycles and two triangular carrier signals. The proposed converter consists of four power switches, four diodes, an inductor, and two capacitors. Detailed converter operations at each switching state with the corresponding voltage and current waveforms of each component are discussed. The functionality and performance of the proposed converter are verified through simulation and experimental results.",
"author_names": [
"Norhassanah Osman",
"Mohamad Fathi Mohamad Elias",
"Nasrudin Abd Rahim"
],
"corpus_id": 216234674,
"doc_id": "216234674",
"n_citations": 2,
"n_key_citations": 0,
"score": 1,
"title": "Design and analysis of three level hybrid boost converter based on T type inverter for solar photovoltaic system",
"venue": "IET Power Electronics",
"year": 2020
},
{
"abstract": "Output voltage of renewable energy sources, such as fuel cell and PV cell, is often low and varies widely with load and environmental conditions. Therefore, the high step up DC DC converter is needed between renewable energy sources and the grid connected inverter. However, voltage stress of rectifier diodes is high and filter is large in traditional voltage source converters in a wide input voltage range. In order to solve the aforementioned problems, a full bridge (FB) three level (TL) converter is proposed. It can operate at both two level and three level modes, so it is suitable for wide input voltage range application. Compared with FB converter, voltage stress of rectifier diodes and the filter can be reduced. Operating principle and control strategy of the proposed converter are illustrated. Design guidelines and example are given. Simulation results of a 1 kW FB TL converter verify the theoretical analysis.",
"author_names": [
"Zhilei Yao",
"Jing Xu",
"Josep M Guerrero"
],
"corpus_id": 25818549,
"doc_id": "25818549",
"n_citations": 6,
"n_key_citations": 0,
"score": 0,
"title": "Control and design of full bridge three level converter for renewable energy sources",
"venue": "2015 IEEE 16th Workshop on Control and Modeling for Power Electronics (COMPEL)",
"year": 2015
},
{
"abstract": "This paper presents the results of a low voltage power converter circuit topology analysis and implementation for electric drive applications. The analysis was conducted for power modules topologies with a rated current of 300 400 A and DC bus voltage of 650 V. The power losses of most popular industrial two and three level topologies based on silicon insulated gate bipolar transistors and silicon carbide metal oxide semiconductor field effect transistors were analyzed at variations of the power factor, modulation index and pulse width modulation frequency. This research was done for power modules of different topologies in various applications. As a result, three level T type circuit topology was selected due to optimal ratio between the power losses, a price and a module size at the pulse width modulation frequency of 16 kHz. There are presented features of the power losses of the T type circuit topology, such as the higher power losses at the lower modulation index. Finally, the driver prototype is presented. There is predicted the efficiency of 98.4% at a rated power of 39 kW. The experimental results demonstrate the reduction of induction load overheating about 30% in comparison with the conventional two level converter.",
"author_names": [
"Sergey Volkov",
"Mikhail Tiapkin",
"Gennadiy Tiapkin"
],
"corpus_id": 216043687,
"doc_id": "216043687",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Analysis and Design of Three Level Low Voltage Converter for Electric Drive Applications",
"venue": "2020 27th International Workshop on Electric Drives: MPEI Department of Electric Drives 90th Anniversary (IWED)",
"year": 2020
},
{
"abstract": "Multilevel technology and power semiconductor devices in series connection can both effectively improve the converter system power capacity. But both of them will enlarge the system size and lead to complex busbar structure which may cause large stray parameters, especially the stray inductances. Large stray inductance has a critical effect during the device transient process and may cause device damage and failure. Therefore, the laminated busbar structure is widely used in high power converters to decrease the wiring stray inductances. In this paper, based on the current commutation loop (CCL) analysis of a 3 level high voltage insulated gate bipolar transistor (HVIGBT) series bridge, the structure design method of the 3 level HVIGBT series connection test platform is described. The influence of the laminated busbar to the adjacent busbar is analyzed and the improved stray parameter calculation method is proposed. The experimental results verify the validity of the structure design method and the veracity of the stray parameter calculation method.",
"author_names": [
"Hualong Yu",
"Zhengming Zhao",
"Ting Lu",
"Liqiang Yuan",
"Shiqi Ji"
],
"corpus_id": 2562409,
"doc_id": "2562409",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "Laminated busbar design and stray parameter analysis of three level converter based on HVIGBT series connection",
"venue": "2015 IEEE Applied Power Electronics Conference and Exposition (APEC)",
"year": 2015
},
{
"abstract": "A novel hybrid resonant zero voltage zero current switching three level converter with capacitive output filter is proposed in this paper, which undergoes half of the input voltage for switches and is suitable for offshore wind farms in medium voltage dc (MVDC) collection systems. The proposed converter, utilizing two transformers with very different power ratings, adopts insulated gate bipolar transistors for all six power switches and operates in discontinuous current mode and can achieve zero current switching for the four main switches and rectifier diodes over the whole load range. Meanwhile, the auxiliary switches with small current rating can realize zero voltage switching naturally. Hence, the switching loss is reduced, which is vital in MVDC applications. By the trajectory formulas of the resonant current and voltage, the trajectory paths can be achieved, which is helpful to compare the peak and turn off currents of switches. The design rules of main parameters can be deduced with the trajectory formulas and paths. The influence of the turns ratio of auxiliary transformer and the resonant capacitance on the peak and turn off currents is discussed in detail. The operation principles of the proposed converter are analyzed and verified by the simulation and experimental results.",
"author_names": [
"Guangfu Ning",
"Wu Chen",
"Liangcai Shu",
"Jianfeng Zhao",
"Wu Cao",
"Jun Mei",
"Chun Liu",
"Guangyao Qiao"
],
"corpus_id": 13757100,
"doc_id": "13757100",
"n_citations": 14,
"n_key_citations": 0,
"score": 0,
"title": "A Hybrid Resonant ZVZCS Three Level Converter for MVDC Connected Offshore Wind Power Collection Systems",
"venue": "IEEE Transactions on Power Electronics",
"year": 2018
},
{
"abstract": "Multi level converters in the mid and high voltage wind power grid applications has been widely studied and applied. Based on the diode neutral point clamped three level converter as the research object, the neutral point potential imbalance in dc side was the fatal weakness of the converter, which could affect the reliability of three level converter. A hardware circuit to solve the problem of neutral point potential balance in the three level converter was presented. Compared to other solutions to the neutral point potential balancing hardware circuit, this circuit does not only make the neutral point potential balance, but also reduce the circuit device. Therfore it can reduce the circuit complexity and the operating costs. Finally, the simulation analysis of the program using MATLAB SIMULINK simulation software indicates that the neutral point potential could achieve balance, so the correctness of the program was verified.",
"author_names": [
"Dong Wei-guan"
],
"corpus_id": 111895690,
"doc_id": "111895690",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Design and Improved of Diode Neutral Point Clamped Three level Converter",
"venue": "",
"year": 2014
},
{
"abstract": "The adoption of SiC devices in high power applications enables higher switching speed, which requires lower circuit parasitic inductance to reduce the voltage overshoot. This paper presents the design of a busbar for a 500 kVA three level active neutral point clamped (ANPC) converter. The layout of the busbar is discussed in detail based on the analysis of the multiple commutation loops, magnetic canceling effect, and DC link capacitor placement. The loop inductance of the busbar is verified with simulation, impedance measurements, and converter experiments. The results match with each other, and the inductances of small and large loop are 6.5 nH and 17.5 nH respectively, which is significantly lower than the busbars of NPC type converters in other references.",
"author_names": [
"Handong Gui",
"Ruirui Chen",
"Jiahao Niu",
"Zheyu Zhang",
"Fred Wang",
"Leon M Tolbert",
"Daniel J Costinett",
"Benjamin J Blalock",
"Benjamin B Choi"
],
"corpus_id": 208883040,
"doc_id": "208883040",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Design of Low Inductance Busbar for 500 kVA Three Level ANPC Converter",
"venue": "2019 IEEE Energy Conversion Congress and Exposition (ECCE)",
"year": 2019
},
{
"abstract": "This paper presents the design of closed loop controllers operating a single phase AC DC three level converter for improving power quality at AC mains. Closed loop inhibits outer voltage controller and inner current controller. Simulations of three level converter with three different voltage and current controller combinations such as PI Hysteresis, Fuzzy Hysteresis and Fuzzy tuned PI ysteresis are carried out in MATLAB/Simulink. Performance parameters such as input power factor and source current total harmonic distortion (THD) are considered for comparison of the three controller combinations. The fuzzy tuned PI voltage controller with hysteresis current controller combination provides a better result, with a source current THD of 0.93% and unity power factor without any source side filter for the three level converter. For load variations of 25% to 100% a THD of less than 5% is obtained with a maximum value of only 1.67% Finally, the fuzzy tuned PI voltage with hysteresis controller combination is implemented in a Xilinx Spartan 6 XC6SLX25 FPGA board for experimental validation of power quality enhancement. A prototype 100 W, 0 24 48 V as output converter is considered for the testing of controller performance. A source current THD of 1.351% is obtained in the experimental study with a power factor near unity. For load variations of 25% to 100% the THD is found to be less than 5% with a maximum value of only 2.698% in the experimental setup which matches with the simulation results.",
"author_names": [
"J Gnanavadivel",
"N Senthil Kumar",
"P Yogalakshmi"
],
"corpus_id": 12775704,
"doc_id": "12775704",
"n_citations": 17,
"n_key_citations": 0,
"score": 0,
"title": "Comparative Study of PI, Fuzzy and Fuzzy tuned PI Controllers for Single Phase AC DC Three Level Converter",
"venue": "",
"year": 2017
},
{
"abstract": "This letter proposes a new three level dc/dc converter configuration for a hybrid energy storage system (HESS) in dc microgrids. It effectively integrates different energy storage devices (ESDs) such as battery and ultracapacitor (UC) using one converter with bidirectional power flow. Furthermore, the proposed converter provides the flexibility of independent regulation of different ESDs with significantly reduced inductor current ripple due to the availability of three voltage levels. The voltage ratings of power semiconductors employed in this converter are also reduced. To further enhance the performance of HESS, a constant switching frequency based model predictive current control is employed for HESS regulation. The design guideline and operating principle of the proposed converter are discussed. Experimental results are presented to verify the efficacy of the proposed converter and control.",
"author_names": [
"Xinan Zhang",
"Benfei Wang",
"Ujjal Manandhar",
"Hoay Beng Gooi",
"Gilbert Hock Beng Foo"
],
"corpus_id": 96431530,
"doc_id": "96431530",
"n_citations": 30,
"n_key_citations": 1,
"score": 0,
"title": "A Model Predictive Current Controlled Bidirectional Three Level DC/DC Converter for Hybrid Energy Storage System in DC Microgrids",
"venue": "IEEE Transactions on Power Electronics",
"year": 2019
}
] |
solar panels cost | [
{
"abstract": "Perovskite solar cells have shown remarkable progress in recent years as power conversion efficiencies have already eclipsed 24% highest of all thin film photovoltaic technologies. In addition to unprecedented optoelectronic properties unseen in traditional semiconductors, low formation energy and solution processability open the door to low cost and high throughput solution coating strategies for commercialization. This review presents recent work on the fabrication of perovskite films by meniscus coating a simple and readily scalable manufacturing technique which includes blade coating and slot die coating. The article outlines the fundamental fluid mechanisms of meniscus coating, discusses drying and crystallization of the perovskite during the coating process, and provides an overview of progress in meniscus coated perovskite solar cells and modules.",
"author_names": [
"Xuezeng Dai",
"Yehao Deng",
"Charles H Van Brackle",
"Jinsong Huang"
],
"corpus_id": 195579996,
"doc_id": "195579996",
"n_citations": 20,
"n_key_citations": 0,
"score": 2,
"title": "Meniscus fabrication of halide perovskite thin films at high throughput for large area and low cost solar panels",
"venue": "International Journal of Extreme Manufacturing",
"year": 2019
},
{
"abstract": "Solar irradiation is a green and sustainable renewable energy source which is largely harnessed through photovoltaic and thermal cell surfaces. It is one of the fastest growing clean power technologies with high global growth figures, due to its simplicity, affordability and abundant availability. Solar power systems is one of the fastest growing interventions augmenting fossil power and its application is now expanding beyond domestic utilization to commercial and industrial dependence. Due to continuous change in the position of the sun together with other salient factors, only a fraction of the suns energy potential is harnessed. The paper is focused on sharing an optimization option that has effectively addressed a major gap experienced in conventional solar power system installation as applicable to light emitting diodes traffic light systems. The continuous movement of the sun limits maximum sun light irradiation absorption and solar trackers are practical solutions to this drawback. The high cost of solar trackers has however been the major limitation to their adoption. The Introduction of microcontroller based solar tracking systems using Arduino board was found to be cost effective, and it improved the efficiency of the solar cells significantly. In the study, the maximum power point tracking algorithm was designed and developed using multiple axis servo motor feedback tracking system, which increased the efficiency of the solar panel array by 23.95%",
"author_names": [
"Timothy Laseinde",
"Dominic Ramere"
],
"corpus_id": 115527027,
"doc_id": "115527027",
"n_citations": 9,
"n_key_citations": 0,
"score": 0,
"title": "Low cost automatic multi axis solar tracking system for performance improvement in vertical support solar panels using Arduino board",
"venue": "",
"year": 2019
},
{
"abstract": "Abstract Solar energy utilization by rural households in Poland contributes to the EU mandated increase in renewable energy use, while lowering emission, dependence on fossil fuels, and energy costs, and improving air quality. Using the survey data collected from owners of passive solar panels in rural areas, this study examines the importance of selected reasons in household decision to participate in the EU funded solar panel subsidy program augmented by contributions from local governments and each household. Associations between nine reasons to invest in a solar panel and characteristics of respondents, their households, and solar panel features were examined using correlation coefficients. An ordered logit technique was also applied and calculations based on estimation results yielded probability changes in the relative importance attached to a selected reason for investing in a panel in response to a change in a respondent, household, or solar panel characteristic. The desire to save on energy used to heat space or water, and lower the energy bill as well as being unemployed or having part time employment increased the probability of viewing the total cost, installation cost, subsidy, and the energy costs prior to having a solar panel as important. Those viewing the solar energy favorably were, overall, less likely to consider lowering the energy bill prior to putting a solar panel as important, while those perceiving solar panel features as troublesome were also less likely to view the listed reasons as important.",
"author_names": [
"Anna Klepacka",
"Wojciech J Florkowski",
"Ting Meng"
],
"corpus_id": 115939732,
"doc_id": "115939732",
"n_citations": 16,
"n_key_citations": 0,
"score": 0,
"title": "Clean, accessible, and cost saving: Reasons for rural household investment in solar panels in Poland",
"venue": "",
"year": 2018
},
{
"abstract": "Testing PV modules are one of the important procedures to ensure the conformity with the standards and quality of this equipment. To implement some of the PV modules tests a data acquisition system is required. This paper presents the design and implementation of a data acquisition system for photovoltaic systems. The developed system is characterized by a low cost board based on a microcontroller. The description of the hardware as well an application to test its performance is presented. The developed system can be used for reading, storing and analyzing information from several photovoltaic systems. Experimental tests are presented to confirm the characteristics of the developed data acquisition board.",
"author_names": [
"Omar Henni",
"Mustapha Belarbi",
"Kamel Haddouche",
"El Habib Belarbi"
],
"corpus_id": 67463819,
"doc_id": "67463819",
"n_citations": 11,
"n_key_citations": 0,
"score": 0,
"title": "Design and Implementation of a Low Cost Characterization System for Photovoltaic Solar Panels",
"venue": "",
"year": 2017
},
{
"abstract": "Abstract In 2017, Bahrain's Cabinet endorsed the country's first national renewable energy action plan. The plan included the installation of residential solar photovoltaic cells as a means of using renewable energy in government built housing units. This was followed by the establishment of the country's first photovoltaic solar panel manufacturing company and the introduction of a net metering policy. However, public acceptance of residential solar panels has not been researched. This study aimed to address this gap through the distribution of an online survey. A total of 764 complete responses were received. The results showed a considerable number of respondents were interested in installing solar panels. However, the respondents recognized several challenges in both buying and installing them, including capital cost, lack of information, and maintenance requirements. This study's findings offer insights on how the public perceives solar panels, along with issues the government needs to address to ensure successful public participation in the use of solar energy in the residential sector in Bahrain.",
"author_names": [
"Maha Alsabbagh"
],
"corpus_id": 169932817,
"doc_id": "169932817",
"n_citations": 21,
"n_key_citations": 1,
"score": 0,
"title": "Public perception toward residential solar panels in Bahrain",
"venue": "Energy Reports",
"year": 2019
},
{
"abstract": "With the enormous growth in the development and utilization of solar energy resources, the proliferation of waste solar panels has become problematic. While current research into solar panels has focused on how to improve the efficiency of the production capacity, the dismantling and recycling of end of life (EOL) panels are seldom considered, as can be seen, for instance, in the lack of dedicated solar panel recycling plants. EOL solar panel recycling can effectively save natural resources and reduce the cost of production. To address the environmental conservation and resource recycling issues posed by the huge amount of waste solar panels regarding environmental conservation and resource recycling, the status of the management and recycling technologies for waste solar panels are systemically reviewed and discussed in this article. This review can provide a quantitative basis to support the recycling of PV panels, and suggests future directions for public policy makers. At present, from the technical aspect, the research on solar panel recovery is facing many problems, and we need to further develop an economically feasible and non toxic technology. The research on solar photovoltaic panels' management at the end of life is just beginning in many countries, and there is a need for further improvement and expansion of producer responsibility.",
"author_names": [
"Yan Xu",
"Jinhui Li",
"Quanyin Tan",
"Anesia Lauren Peters",
"Congren Yang"
],
"corpus_id": 3465973,
"doc_id": "3465973",
"n_citations": 125,
"n_key_citations": 3,
"score": 0,
"title": "Global status of recycling waste solar panels: A review.",
"venue": "Waste management",
"year": 2018
},
{
"abstract": "Use of solar panels is gaining an ever increasing foothold in society, especially on the roof of the houses for feeding domestic electrical appliances in recent times. In many situations, the expensive solar panels stop working due to some external nuisances which goes unnoticed to the users. There is a need of a low cost monitoring system to get information of the defected solar panels for timely repair and maintenance. The design, development, and trial work of a performance monitoring system of distributed solar panels along with automated data logging based on a low cost wireless sensors network has been reported to help the current situation. The developed system can be used up to 146 V and 15.5 A solar cell systems with automatic selection of best resolutions. The system can be extended for wide range of solar cells for material research and development activities. The fabricated system has been used for field trials and very satisfactory results are obtained.",
"author_names": [
"Ricardo Gutierrez-Osuna"
],
"corpus_id": 110552409,
"doc_id": "110552409",
"n_citations": 30,
"n_key_citations": 1,
"score": 0,
"title": "Field Trials and Performance Monitoring of Distributed Solar Panels Using a Low Cost Wireless Sensors Network for Domestic Applications",
"venue": "",
"year": 2011
},
{
"abstract": "Use of solar panels is gaining an ever increasing foothold in society, especially on the roof of the houses for feeding domestic electrical appliances in recent times. In many situations, the expensive solar panels stop working due to some external nuisances which goes unnoticed to the users. There is a need of a low cost monitoring system to get information of the defected solar panels for timely repair and maintenance. The design, development, and trial work of a performance monitoring system of distributed solar panels along with automated data logging based on a low cost wireless sensors network has been reported to help the current situation. The developed system can be used up to 146 V and 15.5 A solar cell systems with automatic selection of best resolutions. The system can be extended for wide range of solar cells for material research and development activities. The fabricated system has been used for field trials and very satisfactory results are obtained.",
"author_names": [
"C Ranhotigamage",
"Subhas Chandra Mukhopadhyay"
],
"corpus_id": 34647353,
"doc_id": "34647353",
"n_citations": 34,
"n_key_citations": 2,
"score": 0,
"title": "Field Trials and Performance Monitoring of Distributed Solar Panels Using a Low Cost Wireless Sensors Network for Domestic Applications",
"venue": "IEEE Sensors Journal",
"year": 2011
},
{
"abstract": "Abstract An improved cleaning system has been developed that uses electrostatic forces to remove dust from the surface of solar panels. A two phase high voltage is applied to the parallel wire electrodes embedded in the glass plate of a solar panel. It was previously demonstrated that the adhering dust can be repelled from the surface of a slightly inclined panel by applying a low frequency high voltage. However, the performance is low for extremely small dust particles. The proposed system improves the performance by the application of a high voltage, reduction of adhesion force, utilization of natural wind, and frequent operation before the deposition of dust. In addition to the cleaning performance, the frequency response and actual power consumption of the high voltage source was investigated to provide data for the design and efficiency evaluation of the system. It was demonstrated that the energy consumption is extremely small with a simple and potentially low cost high voltage source. This technology is expected to increase the efficiency of the mega solar power plants constructed in deserts at low latitudes.",
"author_names": [
"Hiroyuki Kawamoto",
"Bing Guo"
],
"corpus_id": 103108318,
"doc_id": "103108318",
"n_citations": 51,
"n_key_citations": 1,
"score": 0,
"title": "Improvement of an electrostatic cleaning system for removal of dust from solar panels",
"venue": "",
"year": 2018
},
{
"abstract": "Abstract Hot spotting is a reliability problem in photovoltaic (PV) panels where a mismatched cell heats up significantly and degrades PV panel output power performance. High PV cell temperature due to hot spotting can damage the cell encapsulate and lead to second breakdown, where both cause permanent damage to the PV panel. Therefore, the design and development of a hot spot mitigation technique is proposed using a simple, low cost and reliable hot spot activation technique. The hot spots in the examined PV system is detected using FLIR i5 thermal imaging camera. Several experiments have been studied during various environmental conditions, where the PV module P V curve was evaluated in each observed test to analyze the output power performance before and after the activation of the proposed hot spot mitigation technique. One PV module affected by hot spot was tested. The output power increased by approximate to 3.6 W after the activation of the hot spot mitigation technique. Additional test has been carried out while connecting the hot spot PV module in series with two other PV panels. The results indicate that there is an increase of 3.57 W in the output power after activating the hot spot mitigation technique.",
"author_names": [
"Mahmoud Dhimish",
"Violeta Holmes",
"Peter J Mather",
"Martin J N Sibley"
],
"corpus_id": 103520666,
"doc_id": "103520666",
"n_citations": 44,
"n_key_citations": 0,
"score": 0,
"title": "Novel hot spot mitigation technique to enhance photovoltaic solar panels output power performance",
"venue": "",
"year": 2018
}
] |
Norepinephrine: Material-independant, multifunctional surface modification reagent | [
{
"abstract": "A facile approach for material independent surface modification using norepinephrine was investigated. pH induced oxidative polymerization of norepinephrine forms adherent films on vastly different types of material surfaces of noble metals, metal oxides, semiconductors, ceramics, shape memory alloys, and synthetic polymers. Secondary biochemical functionalizations such as immobilization of proteins and growth of biodegradable polyester on the poly(norepinephrine) films were demonstrated.",
"author_names": [
"Sung Min Kang",
"Junsung Rho",
"Insung S Choi",
"Phillip B Messersmith",
"Haeshin Lee"
],
"corpus_id": 207145102,
"doc_id": "207145102",
"n_citations": 243,
"n_key_citations": 3,
"score": 1,
"title": "Norepinephrine: material independent, multifunctional surface modification reagent.",
"venue": "Journal of the American Chemical Society",
"year": 2009
},
{
"abstract": "Dopamine surface chemistry has been of great interest because of its universal coating property and ability to transform nonadhesive molecules into adhesive molecules. Catechol oxidation and intramolecular cyclization underlie the unique property of dopamine (DA) surface chemistry and provide clues for developing new surface modification reagents such as norepinephrine, 5 pyrogallol 2 aminoethane, and perfluorinated DA derivatives. Based on these inspiring properties, a fast and universal surface chemistry technique using 4 (3 aminopropyl) benzene 1,2 diol (3 catecholpropanamine, CPA) is reported herein. A single carbon insertion in the aliphatic chain of DA gives rise to the significantly accelerated intermolecular assembly and surface coating of CPA. The effect of CPA conjugation on an anticoagulant polysaccharide coating is also investigated. The use of CPA instead of DA to make polysaccharide coating materials improves the coating rate, while maintaining excellent antiplatelet performance on the coated surface.",
"author_names": [
"Jeongwoo Hong",
"Dong Gyun Jwa",
"Hyeonbin Ha",
"Jaesung Kwak",
"Min Kim",
"Sung Min Kang"
],
"corpus_id": 143433873,
"doc_id": "143433873",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "4 (3 Aminopropyl) benzene 1,2 diol: An Improved Material Independent Surface Coating Reagent Compared to Dopamine.",
"venue": "Langmuir the ACS journal of surfaces and colloids",
"year": 2019
},
{
"abstract": "Polymers are commonly used materials for microfluidic chip fabrication, because they are standardized in fabrication and low in cost. However, most polymeric materials that are readily fabricated on the industrial scale are hydrophobic, which is inconvenient for the injection and flow of the aqueous solution, resulting in poor analytical performance for biochemical assays. In this work, we present a straightforward and ultrastable surface modification process for polymeric chips. A one step modification by using norepinephrine bitartrate monohydrate as a modification reagent is completed at room temperature. The hydrophilicity of the polymeric surfaces increases dramatically. Surface modification is stable for at least 2.5 years, allowing for autoinjection of aqueous solution into the channels. The chips are applied in the immunoassay of alpha fetoprotein (AFP) The low nonspecific adsorption after modification results in significantly decreased background noise, optimized signal to noise ratios (SNR) and dramatically enhanced reproducibility of the immunoassay. Thirty clinical human serum samples are analyzed; these results strongly correlated with the values obtained using commercial test kits. We anticipate that this surface modification method can be used for immunoassay devices in analytical and biosensing technology.",
"author_names": [
"Haiying Shen",
"Feng Qu",
"Yong Xia",
"Xingyu Jiang"
],
"corpus_id": 3947673,
"doc_id": "3947673",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "Straightforward and Ultrastable Surface Modification of Microfluidic Chips with Norepinephrine Bitartrate Improves Performance in Immunoassays.",
"venue": "Analytical chemistry",
"year": 2018
},
{
"abstract": "3,616,229 10/1971 Wildli et al. 196/63 3,959,078 5/1976 Guire 195/63 4,722,906 2/1988 Guire 435/4 4,973,493 11/1990 Guire 427/2 4,979,959 12/1990 Guire 623/66 5,002,582 3/1991 Guire et al. 623/66 5,258,041 11/1993 Guire et al. 623/66 5,414,075 5/1995 Swan et al. 568/333 5,512,329 4/1996 Guire et al. 427/508",
"author_names": [
"Dale G Swan",
"Louis Park",
"",
"Charles A Hastings"
],
"corpus_id": 67843400,
"doc_id": "67843400",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "United States Patent 19 Swan et al 54 RESTRAINED MULTIFUNCTIONAL REAGENT FOR SURFACE MODIFICATION",
"venue": "",
"year": 2017
},
{
"abstract": "Various micro surface modification approaches including photolithography, dip pen lithography and ink jet systems have been developed and used to extend the functionalities of solid surfaces. While those approaches work in the \"open space\" push pull systems which work in solutions have recently drawn considerable attention. However, the confining flows performed by push pull systems have realized only the dispense process, while microscale, region selective chemical reactions have remained unattainable. This study reports a microchemical pen that enables region selective chemical reactions for the micro surface modification/patterning. The chemical pen is based on the principle of microfluidic laminar flows and the resulting mixing of reagents by the mutual diffusion. The tiny diffusion layer performs as the working region. This report represents the first demonstration of an open microreactor in which two different reagents react on a real solid sample. The multifunctional characteristics of the microchemical pen are confirmed by different types of reactions in many research areas, including inorganic chemistry, polymer science, electrochemistry and biological sample treatment.",
"author_names": [
"Sifeng Mao",
"Chiho Sato",
"Yuma Suzuki",
"Jianmin Yang",
"Hulie Zeng",
"Hizuru Nakajima",
"Ming Yang",
"Jin-Ming Lin",
"Katsumi Uchiyama"
],
"corpus_id": 6380744,
"doc_id": "6380744",
"n_citations": 8,
"n_key_citations": 0,
"score": 0,
"title": "Microchemical Pen: An Open Microreactor for Region Selective Surface Modification.",
"venue": "Chemphyschem a European journal of chemical physics and physical chemistry",
"year": 2016
},
{
"abstract": "As a result of their extraordinarily large surfaces and well defined pores, the design of a multifunctional metal organic framework (MOF) is crucial for drug delivery but has rarely been reported. In this paper, a novel drug delivery system (DDS) based on nanoscale MOF was developed for use in cancer diagnosis and therapy. This MOF based tumor targeting DDS was fabricated by a simple postsynthetic surface modification process. First, magnetic mesoporous nanomaterial Fe MIL 53 NH2 was used for encapsulating the drug and served as a magnetic resonance contrast agent. Moreover, the Fe MIL 53 NH2 nanomaterial exhibited a high loading capacity for the model anticancer drug 5 fluorouracil (5 FU) Subsequently, the fluorescence imaging agent 5 carboxyfluorescein (5 FAM) and the targeting reagent folic acid (FA) were conjugated to the 5 FU loaded Fe MIL 53 NH2, resulting in the advanced DDS Fe MIL 53 NH2 FA 5 FAM/5 FU. Owing to the multifunctional surface modification, the obtained DDS Fe MIL 53 NH2 FA 5 FAM/5 FU shows good biocompatibility, tumor enhanced cellular uptake, strong cancer cell growth inhibitory effect, excellent fluorescence imaging, and outstanding magnetic resonance imaging capability. Taken together, this study integrates diagnostic and treatment aspects into a single platform by a simple and efficient strategy, aiming for facilitating new possibilities for MOF use for multifunctional drug delivery.",
"author_names": [
"Xuechuan Gao",
"Ma-Yue Zhai",
"Weihua Guan",
"Jingjuan Liu",
"Zhiliang Liu",
"Alatangaole Damirin"
],
"corpus_id": 206438198,
"doc_id": "206438198",
"n_citations": 117,
"n_key_citations": 0,
"score": 0,
"title": "Controllable Synthesis of a Smart Multifunctional Nanoscale Metal Organic Framework for Magnetic Resonance/Optical Imaging and Targeted Drug Delivery.",
"venue": "ACS applied materials interfaces",
"year": 2017
},
{
"abstract": "Green chemistry, in particular, the principle of atom economy, has defined new criteria for the efficient and sustainable production of synthetic compounds. In complex nanomaterials, the number of embedded functional entities and the energy expenditure of the assembly process represent additional compound associated parameters that can be evaluated from an economic viewpoint. In this Perspective, we extend the principle of atom economy to the study and characterization of multifunctionality in nanocarriers, which we define as \"multifunctional efficiency\" This concept focuses on the design of highly active nanomaterials by maximizing integrated functional building units while minimizing inactive components. Furthermore, synthetic strategies aim to minimize the number of steps and unique reagents required to make multifunctional nanocarriers. The ultimate goal is to synthesize a nanocarrier that is highly specialized but practical and simple to make. Owing to straightforward crystal engineering, metal organic framework (MOF) nanoparticles are an excellent example to illustrate the idea behind this concept and have the potential to emerge as next generation drug delivery systems. Here, we highlight examples showing how the combination of the properties of MOFs e.g. their organic inorganic hybrid nature, high surface area, and biodegradability) and induced systematic modifications and functionalizations of the MOF's scaffold itself lead to a nanocarrier with high multifunctional efficiency.",
"author_names": [
"Ralph Freund",
"Ulrich Lachelt",
"Tobias Gruber",
"Bastian Ruhle",
"Stefan Wuttke"
],
"corpus_id": 4417245,
"doc_id": "4417245",
"n_citations": 134,
"n_key_citations": 0,
"score": 0,
"title": "Multifunctional Efficiency: Extending the Concept of Atom Economy to Functional Nanomaterials.",
"venue": "ACS nano",
"year": 2018
},
{
"abstract": "A systematic investigation into the influence of the degree of fluorination on the static and dynamic wetting behavior of TiO2 based nanobelt (TNB) particles with various liquids is described. The effect of the degree of fluorination and the surface tension of the liquid on the occurrence and stability of liquid marbles, foams or dispersions are studied and the wetting behavior and arrangement of particles at the air liquid surface are observed. Using contact angle (th) measurements, the relation between the type of particle stabilized material and th is established. For liquids of relatively high tension like water or formamide which do not wet the fluorinated particles, a powder like material (marble) is formed. For polar oils of intermediate tension (35 50 mN m 1) which partially wet the fluorinated particles, stable air in oil foams can be prepared in which particles form a close packed layer enveloping air bubbles. Liquids of relatively low tension, e.g. ethanol or polydimethylsiloxane, wet the particles forming a uniform dispersion and partial sedimentation. By contrast, the as prepared hydrophilic TNB particles are rapidly wetted by all the liquids as expected due to their high surface energy. The stable cross stacked TNB particles with fluoroalkylsilane (FAS) modification could be a versatile platform in a wide range of applications, especially for fluidic devices (e.g. biofluids, gas sensing, and lab on a chip devices) In a proof of concept study, the oil water separation performance of fabrics with chemically stable TNB/FAS coating and the liquid isolation by a TNB/FAS shell for highly sensitive gas sensing or reagent assays are investigated.",
"author_names": [
"Yuekun Lai",
"Huanfu Zhou",
"Zheng Zhang",
"Yuxin Tang",
"Jeffrey Weng Chye Ho",
"Jianying Huang",
"Qiuling Tay",
"Ke-Qin Zhang",
"Zhiling Chen",
"Bernard P Binks"
],
"corpus_id": 98689186,
"doc_id": "98689186",
"n_citations": 15,
"n_key_citations": 0,
"score": 0,
"title": "Multifunctional TiO2 Based Particles: The Effect of Fluorination Degree and Liquid Surface Tension on Wetting Behavior",
"venue": "",
"year": 2015
},
{
"abstract": "Recently, metal organic gels (MOGs) appear as a potential alternative to the well known metal organic frameworks due to the easier and more straightforward shaping and other unique features. However, the modification of MOGs with noble metal nanoparticles is still in its infancy. On the other hand, developing multifunctional SERS substrate materials with a facile way still remains a great challenge. Herein, silver nanoparticles/metal organic gels (AgNPs/MOGs) hybrid, a novel dual functional SERS active platform that is both Raman signal molecule and highly sensitive SERS substrate, was fabricated by a one pot approach for the first time. The AgNPs/MOGs hybrid, which was obtained by simply mixing 4 (2,2':6',2' terpyridine) 4' ylbenzoic acid (Hcptpy) and silver ion (Ag+ followed by heating without adding extra reducing reagent, exhibited an outstanding Raman signal due to the combination of the Raman label source of Hcptpy and the localized surface plasmon resonance properties of AgNPs, endowing it an exc.",
"author_names": [
"Yang Li",
"Mao Xia Guo",
"Li He",
"Cheng Zhi Huang",
"Yuan Fang Li"
],
"corpus_id": 104329866,
"doc_id": "104329866",
"n_citations": 11,
"n_key_citations": 0,
"score": 0,
"title": "Green One Pot Synthesis of Silver Nanoparticles/Metal Organic Gels Hybrid and Its Promising SERS Application",
"venue": "",
"year": 2019
},
{
"abstract": "Abstract We report a method for preparing chemically stable catecholamine coatings on solid substrates. The catecholamine, norepinephrine, was used as a surface modification reagent, forming a coating of poly(norepinephrine) under alkaline conditions. The stability of the polymer layer was enhanced by using a post oxidation treatment, and the resulting surface showed superior stability in the presence of a strong acid or a harsh organic solvent.",
"author_names": [
"Yooil Jeon",
"Sung Min Kang"
],
"corpus_id": 97460717,
"doc_id": "97460717",
"n_citations": 14,
"n_key_citations": 0,
"score": 0,
"title": "Chemically stable poly(norepinephrine) coatings on solid substrates by post oxidation",
"venue": "",
"year": 2013
}
] |
MoS 2 A New Direct-Gap Semiconductor | [
{
"abstract": "The electronic properties of ultrathin crystals of molybdenum disulfide consisting of N=1,2,,6 S Mo S monolayers have been investigated by optical spectroscopy. Through characterization by absorption, photoluminescence, and photoconductivity spectroscopy, we trace the effect of quantum confinement on the material's electronic structure. With decreasing thickness, the indirect band gap, which lies below the direct gap in the bulk material, shifts upwards in energy by more than 0.6 eV. This leads to a crossover to a direct gap material in the limit of the single monolayer. Unlike the bulk material, the MoS2 monolayer emits light strongly. The freestanding monolayer exhibits an increase in luminescence quantum efficiency by more than a factor of 104 compared with the bulk material.",
"author_names": [
"Kin Fai Mak",
"Changgu Lee",
"James C Hone",
"Jie Shan",
"Tony F Heinz"
],
"corpus_id": 40589037,
"doc_id": "40589037",
"n_citations": 9403,
"n_key_citations": 133,
"score": 0,
"title": "Atomically thin MoS2: a new direct gap semiconductor.",
"venue": "Physical review letters",
"year": 2010
},
{
"abstract": "Two dimensional (2D) layered materials, particularly semiconducting transition metal dichalcogenides (TMDs) such as MoS2 and WSe2, have already attracted tremendous research efforts, due not only to their atomically thin thickness, but also to many exciting new phenomena associated with new materials. Recent advances in heterostructures formed by vertically stacked or laterally stitched 2D semiconductors further show their promise for novel device applications. Here, I will present our recent endeavors on the material synthesis and fundamental study of 2D TMDs grown by chemical vapor deposition (CVD) In particular, I will present CVD grown noble metal dichalcogenides, such as PtSe2 and PdSe2, with strongly layer number dependent properties. This new type 2D material is promising for realizing metal semiconductor junctions by local engineering the semiconducting and metallic phases via layer control, providing a feasible scheme to solve the issue of high metal contact resistance commonly occurred in 2D semiconductors.",
"author_names": [
"Wen-Hao Chang"
],
"corpus_id": 202093085,
"doc_id": "202093085",
"n_citations": 0,
"n_key_citations": 0,
"score": 1,
"title": "2D Layered Semiconductors beyond MoS2",
"venue": "2019 International Symposium on VLSI Technology, Systems and Application (VLSI TSA)",
"year": 2019
},
{
"abstract": "The advance in designing arrays of ultrathin two dimensional optical nanoresonators, known as metasurfaces, is currently enabling a large variety of novel flat optical components. The remarkable control over the electromagnetic fields offered by this technology can be further extended to the active regime in order to manipulate the light characteristics in real time. In this contribution, we couple the excitonic resonance of atomic thin MoS2 monolayers with gap surface plasmon (GSP) metasurfaces, and demonstrate selective enhancement of the exciton plasmon polariton emissions. We further demonstrate tunable emissions by controlling the charge density at the interface through electrically gating in the Metal Oxide Semiconductor (MOS) structure. Straddling two very active fields of research, this demonstration of electrically tunable light emitting metasurfaces enables real time manipulation of light matter interactions at the extreme subwavelength dimensions.",
"author_names": [
"Pei-Nan Ni",
"Andres De Luna Bugallo",
"Victor M Arellano Arreola",
"Mario Flores Salazar",
"Elodie Strupiechonski",
"Virginie Brandli",
"Rajath Sawant",
"B Alloing",
"Patrice Genevet"
],
"corpus_id": 196470809,
"doc_id": "196470809",
"n_citations": 13,
"n_key_citations": 0,
"score": 0,
"title": "Gate Tunable Emission of Exciton Plasmon Polaritons in Hybrid MoS2 Gap Mode Metasurfaces",
"venue": "ACS Photonics",
"year": 2019
},
{
"abstract": "This chapter discusses the latest advances in the development of various two dimensional (2D) metal dichalcogenides as a new direction in modern science and technology. The chapter begins with a review of the physical chemical properties of transition metal dichalcogenides (TMDs) and how the tunable electronic structure of TMDs makes them attractive for a variety of applications. Most of the 2D TMDs are described in detail: molybdenum disulfide (MoS 2 titanium disulfide (TiS 2 tungsten disulfide (WS 2 molybdenum diselenide (MoSe 2 tungsten diselenide (WSe 2 and niobium diselenide (NbSe 2 Then, it is shown how to turn properties of 2D semiconductors through surface functionalization, and the new concept of UV photodetectors based on 2D semiconductors is investigated. The chapter concludes on the future impact of the combination of the 2D semiconductor nano crystals into 3D structures.",
"author_names": [
"Serge Zhuiykov"
],
"corpus_id": 104244487,
"doc_id": "104244487",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "New Directions in Science Technology Atomically Thin Metal Dichalcogenides",
"venue": "",
"year": 2018
},
{
"abstract": "Graphene and phosphorene are two major types of atomically thin two dimensional materials under extensive investigation. However, the zero band gap of graphene and the instability of phosphorene greatly restrict their applications. Here, we make first principle unbiased structure search calculations to identify a new buckled graphene like PC6 monolayer with a number of desirable functional properties. The PC6 monolayer is a direct gap semiconductor with a band gap of 0.84 eV, and it has an extremely high intrinsic conductivity with anisotropic character (i.e. its electron mobility is 2.94 x 105 cm2 V 1 s 1 along the armchair direction, whereas the hole mobility reaches 1.64 x 105 cm2 V 1 s 1 along the zigzag direction) which is comparable to that of graphene. On the other hand, PC6 shows a high absorption coefficient (105 cm 1) in a broad band, from 300 to 2000 nm. Additionally, its direct band gap character can remain within a biaxial strain of 5% All these appealing properties make the predicted PC6 monolayer a promising candidate for applications in electronic and photovoltaic devices.",
"author_names": [
"Tong Yu",
"Ziyuan Zhao",
"Yuanhui Sun",
"Aitor Bergara",
"Jianyan Lin",
"Shoutao Zhang",
"Haiyang Xu",
"Lijun Zhang",
"Guochun Yang",
"Yichun Liu"
],
"corpus_id": 58636389,
"doc_id": "58636389",
"n_citations": 56,
"n_key_citations": 1,
"score": 0,
"title": "Two Dimensional PC6 with Direct Band Gap and Anisotropic Carrier Mobility.",
"venue": "Journal of the American Chemical Society",
"year": 2019
},
{
"abstract": "Van der Waals heterostructures from atomically thin 2D materials have opened up new realms in modern semiconductor industry. Recently, 2D layered semiconductors such as MoS2 and SnSe2 have already demonstrated excellent electronic and optoelectronic properties due to their high electron mobility and unique band structures. Such combination of SnSe2 with MoS2 may provide a novel platform for the applications in electronics and optoelectronics. Thus, we constructed SnSe2/MoS2 based van der Waals heterostructures using MoS2 as templates, which may enrich the family of 2D van der Waals heterostructures. We demonstrate that the vdW heterostructures with high symmetry crystallographic directions show efficient interlayer charge transfer due to the strong coupling. This strong coupling is confirmed by theory calculations, low temperature photoluminescence (PL) spectra, and electrical transport properties. High performance photodetector based on the vdW heterostructure has been demonstrated with a high responsivity of up to 9.1 x 103 A W 1 which is higher by two orders of magnitude than those MoS2 only devices. The improved performance can be attributed to the efficient charge transfer from MoS2 to SnSe2 at the interface.",
"author_names": [
"Xing Zhou",
"Nan Zhou",
"Chao Li",
"Hongyue Song",
"Qi Zhang",
"Xiaozong Hu",
"Lin Gan",
"Huiqiao Li",
"Jing-Tao Lu",
"Jun Luo",
"Jie Xiong",
"Tianyou Zhai"
],
"corpus_id": 136158580,
"doc_id": "136158580",
"n_citations": 129,
"n_key_citations": 0,
"score": 0,
"title": "Vertical heterostructures based on SnSe 2 /MoS 2 for high performance photodetectors",
"venue": "",
"year": 2017
},
{
"abstract": "The new 2D transitions metal dichalcogenide (TMDs) as MoS2 represents ideal material for multiple purposes. MoS2 is promising for electronic transistor and fundamentals phenomena such as superconductivity or valleytronic. It is a rich platform for optoelectronic; excitonic effects have high binding energy, strain engineering can induce a high tunability of the band gap itself. Moreover, MoS2 transit between different crystalline phase (2H 1T) making this material interesting for memristive devices and energy storage. Nanomechanical systems have been at the heart of recent physic discoveries of importance, from the detection of cosmic gravitational waves to the sensitivity record for detection of mass or force. It is a recent and almost universal probe of condensed matters issues and quantum mechanics. Since 2007, the emergence of suspended atomically thin materials, with the largest geometrical aspect ratio which can be obtained, brought new insight in nanomechanical resonators with very low mass and spring constant, high elongation resistance, high frequency tuning and especially strong mechanical non linearities. A high potential release in MoS2 for nanomechanics. It opens new experimental perspectives by measuring unique intrinsic properties when transduced into the mechanical motion. We propose to focus on unexpected electrical behaviors measured in our samples: a strong photodoping under illumination and a hysteretic loop in the I V curve corresponding to a memristive effect. We use the sensitivity of our mechanical MoS2 membrane as a non conventional probe to explore deeply these intriguing behaviors and we have seen a strong effect of softening due to the nonlinear charge of the devices. Figure 1 We explore these topics within unique sample geometry of a suspended single layer membrane of the MoS2 embedded in a nano opto electro mechanical system (NOEMS) 1. Chaste, J. et al. Intrinsic Properties of Suspended MoS2 on SiO2/Si Pillar Arrays for Nanomechanics and Optics. ACS Nano (2018) doi:10.1021/acsnano.7b07689 2. Chaste, J. et al. Nanostructures in suspended monoand bilayer epitaxial graphene. Carbon 125, 162 167 (2017)",
"author_names": [
"Julien Chaste",
"Imen Hnid",
"Ali Madouri",
"Alan Durnez",
"Xavier Lafosse",
"- Meng",
"Qiang Zhao",
"A T Charlie Johnson",
"Remy Braive",
"Abdelkarim Ouerghi"
],
"corpus_id": 167212762,
"doc_id": "167212762",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Strong nanomechanical softening signature induced by memristive charge accumulation in suspended monolayer MoS 2",
"venue": "",
"year": 2018
},
{
"abstract": "Two dimensional (2D) atomic crystals and van der Waals heterostructures constitute an emerging platform for developing new functional ultra thin electronic and optoelectronic materials for novel energy efficient devices. However, in most thin film optical applications, there is a long existing trade off between the effectiveness of light matter interactions and the thickness of semiconductor materials, especially when the materials are scaled down to atom thick dimensions. Consequently, enhancement strategies can introduce significant advances to these atomically thick materials and devices. Here we demonstrate enhanced absorption and photoluminescence generation from MoS2 monolayers coupled with a planar nanocavity. This nanocavity consists of an alumina nanolayer spacer sandwiched between monolayer MoS2 and an aluminum reflector, and can strongly enhance the light matter interaction within the MoS2, increasing the exclusive absorption of monolayer MoS2 to nearly 70% at a wavelength of 450 nm. The nanocavity also modifies the spontaneous emission rate, providing an additional design freedom to control the interaction between light and 2D materials.",
"author_names": [
"Corey Janisch",
"Haomin Song",
"Chanjing Zhou",
"Zhong Lin",
"Ana Laura Elias",
"Dengxin Ji",
"Mauricio Terrones",
"Qiaoqiang Gan",
"Zhiwen Liu"
],
"corpus_id": 138871194,
"doc_id": "138871194",
"n_citations": 58,
"n_key_citations": 0,
"score": 0,
"title": "MoS 2 monolayers on nanocavities: enhancement in light matter interaction",
"venue": "",
"year": 2016
},
{
"abstract": "Quantification of lattice thermal conductivity of two dimensional semiconductors like MoS2 is necessary for the design of electronic and thermoelectric devices, but direct experimental measurements on free standing samples is challenging. Molecular dynamics simulations, with appropriate corrections, can provide a reference value for thermal conductivity for these material systems. Here, we construct a new empirical forcefield of the Stillinger Weber form, parameterized to phonon dispersion relations, lattice constants and elastic moduli and we use it to compute a material intrinsic thermal conductivity of 38.1 W/m K at room temperature and estimate a maximum thermal conductivity of 85.4 W/m K at T 200 K. We also identify that phonon scattering by the large isotopic mass distribution of Mo and S contributes a significant correction >45% to the thermal conductivity at low temperatures. (c) 2019 Author(s) All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http:/creativecommons.org/licenses/by/4.0/ https:/doi.org/10.1063/1.5085336 In plane thermal transport is an important consideration for the design of nanoelectronic and thermoelectric devices made from layered and two dimensional (2D) materials which possess some of the lowest out of plane thermal boundary conductance for solidsolid interfaces.1 Lattice thermal conductivity also determines the thermal profile of growing two dimensional crystals in exothermic synthesis techniques like chemical vapor deposition and is an important metric for the fabrication of energy harvesting devices based on the thermoelectric effect.2 4 Despite this importance, definitive experimental measurements of fundamental thermal properties of these materials like lattice thermal conductivity have not been conclusive. The primary experimental challenges, as detailed in recent reviews,2,5 stem from difficulties in accurately measuring temperature gradients on atomic length scales in suspended monolayer samples. Further, thermal conductivity of suspended monolayers and sub nm thin materials is greatly quenched (by up to 85% when these monolayers are supported on a substrate or are investigated using contact probes.6,7 Even state of the art noncontact techniques for thermal conductivity measurement like optothermal Raman are undermined by several implicit assumptions about optical absorption and equilibrium of phonon modes8 and are affected by heat losses to the environment9 leading to large errors in reported values of thermal conductivity.10 12 Further, such techniques involving localized laser heating can only be used to investigate room temperature and high temperature thermal conductivity and cannot readily access low temperature regimes.13 In contrast, atomistic MD simulations are an attractive method for estimating temperature dependent thermal conductivity of suspended monolayer systems directly from nm scale temperature gradients. Specifically, classical non equilibrium molecular dynamics (NEMD) provides a computationally inexpensive way of computing lattice thermal conductivity for monolayer materials, which includes the full anharmonicity of interatomic forces within a steady state (i.e. dynamic and non equilibrium) simulation. Classical NEMD simulations offers several advantages over the calculation of lattice thermal conductivity by ab initio atomistic simulations. Solutions to the phonon Boltzmann transport equation from ab initio simulations involve strong assumptions about phonon scattering rates and lifetimes as well as boundary conditions for phonon scattering.14 19 These assumptions are reflected in the large scatter in the AIP Advances 9, 035042 (2019) doi: 10.1063/1.5085336 9, 035042 1",
"author_names": [
"Aravind Krishnamoorthy",
"Pankaj Rajak",
"Payam Norouzzadeh",
"David J Singh",
"Rajiv K Kalia",
"Aiichiro Nakano",
"Priya Vashishta"
],
"corpus_id": 140067355,
"doc_id": "140067355",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Thermal conductivity of MoS 2 monolayers from molecular dynamics simulations",
"venue": "",
"year": 2019
},
{
"abstract": "We present photosensitivity in large area physical vapour deposited mono and bi layer MoS2 films. Photo voltaic effect was observed in single layer MoS2 without any apparent rectifying junctions, making device fabrication straightforward. For bi layers, no such effect was present, suggesting strong size effect in light matter interaction. The photo voltaic effect was observed to highly direction dependent in the film plane, which suggests that the oblique deposition configuration plays a key role in developing the rectifying potential gradient. To the best of our knowledge, this is the first report of any large area and transfer free MoS2 photo device with performance comparable to their exfoliated counterparts. 1 Correspondence/Findings Atomically thin semiconductor materials with large band gaps are touted for aggressively scaled electronic and optoelectronic applications [1] Even though graphene does not have a band gap, its advent has galvanized the research on two dimensional (2D) materials, notably the transition metal di chalcogenides (TMD) [2] The best example is molybdenum di sulfide (MoS2) which has received significant attention in the scientific community due to high carrier mobility, large current on/off ratio and excellent interface quality with the gate dielectrics [3] Bulk MoS2 has an indirect band gap of 1.2 eV which changes to a direct band gap of 1.83 eV for a monolayer MoS2 [4,5] This leads to unprecedented light matter interaction (high absorption coefficient and efficient electron hole pair generation under photo excitation) that has been studied in the form of photoluminescence, photoreponsivity, photoconductivity and photo voltaics [1,6 10] While the existing literature on mono or fewlayer MoS2 opto electronics promise revolutionary capabilities of next generation devices, all these studies are performed on exfoliated flakes. Since exfoliation is not a sustainable path beyond basic science, there is a critical need for large area growth of mono layer MoS2 and its opto electronic characterization. This provides the Correspondence: [email protected] Mechanical Nuclear Engineering, the Pennsylvania State University, University Park, PA 16802, USA Full list of author information is available at the end of the article (c) 2014 Wang et al. licensee Springer. This is a Attribution License (http:/creativecommons.or in any medium, provided the original work is p 1 Approved for public releas motivation for the present study, where we deposit large area cm) mono and bi layer MoS2 through magnetron sputtering and then study the effect of layer number on the interaction of matter and light. Since the deposition is directly performed on the desired substrate, our fabrication processes are performed directly on the specimen. Specimen transfer to another sample is not needed and contamination is avoided. To the best of our knowledge, this is the first report of any large area, transfer free monolayer MoS2 photo voltaic or photodetector device with performance comparable to their exfoliated counterparts. We employed physical vapour deposition with base pressure below 5x10 Torr for atomically sharp and clean interfaces. The mono and bi layer specimens were grown on 100 nm thick thermal oxide coated silicon wafer pieces via magnetron sputtering using a solid 3.3 cm diameter MoS2 target of 99.95% purity. The substrates were ultra sonically cleaned prior to introduction via a vacuum load lock and mounted on an electrically grounded fixture with heating and rotation features. The substrates were then heated to 350degC while ultra high purity argon gas was introduced at a constant flow rate of 25 sccm to a pressure of 15 mTorr. Figure 1a shows the deposition setup schematically. Figure 1b shows the cross sectional transmission electron microscopy of the specimens using a FEI Titan microscope for thickness measurements and calibration. The red dashed lines are superimposed on the figure to reveal the parallel atomic layers with likely turbo stratic structure, where all basal n Open Access article distributed under the terms of the Creative Commons g/licenses/by/4.0) which permits unrestricted use, distribution, and reproduction roperly credited. e; distribution unlimited. Figure 1 Experimental settings and characterization of 2D MoS2 films directly grown by sputtering. (a) schematic of the pulsed dc magnetron sputtering configuration (b) cross sectional TEM (dashed lines are added for highlighting the MoS2 layers, (c) x ray photoelectron spectroscopy data revealing the structure (d) 1 cmx 1 cm MoS2 specimen packaged for van der Pauw measurements showing the large active area. Table 1 Dark dc resistivity of the mono and bi layer MoS2 specimens Specimen type Specimen 1 Specimen 2 Mono layer 1.87 x 10 ohm cm 1.88 x 10 ohm cm Bi layer 2.98 x 10 ohm cm 2.93 x 10 ohm cm Wang et al. Nano Convergence 2014, 1:22 Page 2 of 5 http:/www.nanoconvergencejournal.com/content/1/1/22 planes are parallel and coplanar, but rotated about the crystals' z axes. Or in other words, the specimens are not single crystal layers, but rather a large ensemble of small MoS2 grains with uniform thickness and excellent lateral coherence. Specific processing conditions in terms of power modulation to the sputtering cathode were selected based on prior work [11,12] to obtain atomic scale thickness control and very high crystallinity. Both Raman and x ray photoelectron spectroscopy were then employed to characterize the specimens for thickness and stoichiometry. Figure 1c shows high resolution Mo 3d spectra with Mo peak shift to 229.0 eV indicating the +4 oxidation state for Mo, the hallmark of covalent bonding with sulfur in MoS2 [13] Figure 1c also shows a peak identified at 232.2 eV, which is the 3d3/2 peak for Mo and its shift from 231.4 eV also indicates bonding to S. To verify the continuity and integrity of the deposited films, we prepared specimens with 1 cm x 1 cm active area, whereas the conventional practice is to pattern the semiconducting material as micro to nanoscale strips with metallic contacts as source and drain for a transistor configuration. A physical shadow mask was used to protect the specimen while exposing the four corners, on which 5 nm thick titanium and 100 nm thick gold were evaporated to make the electrical contacts. The chip is then mounted on another wafer piece with large gold plated electrodes using a thermal tape. The four corners of the specimen are then wire bonded to the larger pads. Figure 1c shows a specimen prepared for van der Pauw characterization [14] of the electrical resistivity under both dark and illuminated conditions. The van der Pauw setup was calibrated with a calibration specimen to achieve 5% error limit. Table 1 shows the dark dc conductivity results for the specimens. Such high values of resistivity are due to the fact that ultra high vacuum condition results in cleaner MoS2 surfaces and domain structures. More importantly, the device fabrication process did not require the film to be transferred to a different substrate, so the associated contamination is avoided. 2 Approved for public releas After dark dc characterization, we illuminated the devices with a 30 W light bulb located at about 10 cm distance. The measured luminous flux per unit area was measured to be about 24 kLux using a light meter. Figure 2a and b show the experimental results for the mono and bi layer specimens. For the mono layer, we observed the highest open circuit photo induced voltage of about 9.25 mV (without any applied bias) This value is significantly reduced to about 0.75 mV for the bi layer specimen. These experiments were performed for negative bias to exhibit consistent behaviour. For even thicker specimens, we did not observe any appreciable photovoltaic effects. We also observe that the effect is extremely direction dependent. For example, Figure 2c and d shows the photo voltage measurement on the terminals perpendicular to that shown in Figure 2a and b. Such change in direction resulted in dramatic changes in the voltage obtained from the monolayer specimens (Figure 2c) and completely eliminated any such voltage in the bilayer specimens (Figure 2d) Note that in Figure 2d, the dark and illuminated behaviour is almost the same. A remarkable feature of this study is the apparent ohmic nature of the electrical contacts, as shown in Figure 2. Almost all existing photo detector devices in the literature [6 9,15,16] present Schottky type contact and the choice of electrode work function is very critical in 2D devices to obtain ohmic contacts. Desired features of the contact are (i) small lattice mismatch at the interface (ii) maximized overlap between the density of states (DOS) at both sides of the interface, (iii) large DOS at the Fermi level throughout the interface region to form delocalized states with low effective electron mass in order to e; distribution unlimited. Figure 2 I V characteristics under dark and 1.2 milli Watts illumination for (a) mono layer and (b) bi layer MoS2 devices. The corresponding values, when measured with electrodes at perpendicular direction in (c) monolayer and (d) bilayer devices exhibit remarkable anisotropy in photo sensitivity. Predominant nature of ohmic contact is seen for all the devices. Wang et al. Nano Convergence 2014, 1:22 Page 3 of 5 http:/www.nanoconvergencejournal.com/content/1/1/22 efficiently transfer electrons between the metal and the semiconductor, (iv) a minimized potential barrier at the interface to maximize current injection [17] Our choice of metals for the electrical contacts therefore appears to be satisfying these conditions. While it is expected that the direct band gap will enhance the photon absorption, formation of an electrical bias through predominantly ohmic contact as seen in Figure 2 is unprecedented. One way to view the observed phenomenon could be the negative photoconductivity (increase in resistivity under photo excit",
"author_names": [
"Baoming Wang",
"Christopher Muratore",
"Andrey A Voevodin",
"Md Amanul Haque"
],
"corpus_id": 45788245,
"doc_id": "45788245",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "AFRL RX WP TP 2014 0146 PHOTOSENSITIVITY OF LARGE AREA PHYSICAL VAPOR DEPOSITED MONO AND BILAYER MOS 2 POSTPRINT",
"venue": "",
"year": 2014
}
] |
Advances in Electronics and Electron Physics | [
{
"abstract": "Digital techniques in electron off axis holography, G. Ade optical symbolic substitution architectures, M.S. Alam and M.A. Karim semiconductor quantum devices, M. Cahay and S. Bandyopadhyay fuzzy relations and applications, B. de Baets and E. Kerre basis algorithms in mathematical morphology, R. Jones and I.D. Svalbe mirror bank energy analyzers, S.P. Karetskaya et al.",
"author_names": [
"Ladislaus Laszlo Marton",
"Robert L Sproull"
],
"corpus_id": 121947651,
"doc_id": "121947651",
"n_citations": 2026,
"n_key_citations": 24,
"score": 1,
"title": "Advances in Electronics and Electron Physics",
"venue": "",
"year": 1958
},
{
"abstract": "",
"author_names": [
"Mario Bertero"
],
"corpus_id": 116311390,
"doc_id": "116311390",
"n_citations": 136,
"n_key_citations": 16,
"score": 0,
"title": "Advances in Electronics and Electron Physics",
"venue": "",
"year": 1989
},
{
"abstract": "",
"author_names": [
""
],
"corpus_id": 107999666,
"doc_id": "107999666",
"n_citations": 119,
"n_key_citations": 9,
"score": 0,
"title": "Advances in electronics and electron physics",
"venue": "",
"year": 1990
},
{
"abstract": "",
"author_names": [
"Laurence J Marton"
],
"corpus_id": 120382959,
"doc_id": "120382959",
"n_citations": 47,
"n_key_citations": 0,
"score": 0,
"title": "Advances in Electronics and Electron Physics. Vol.30",
"venue": "",
"year": 1955
},
{
"abstract": "",
"author_names": [
"Matthias Nussbaum"
],
"corpus_id": 124825001,
"doc_id": "124825001",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Acoustic Imaging With Electronic Circuits Advances In Electronics And Electron Physics Volume 11",
"venue": "",
"year": 2016
},
{
"abstract": "The Free Electron Laser (FEL) principle has been known since the early 1970's but for many years FEL's have played a marginal role in comparison with conventional lasers. Only in recent years it has become clear that these devices have the potential of becoming exceedingly powerful light sources in the vacuum ultraviolet (VUV) and X ray regime. In my talk I will first deal with undulator radiation since it is intimitely related to FEL radiation, then explain the low gain FEL and finally treat the highgain FEL based on the principle of Self Amplified Spontaneous Emission (SASE) SASE FEL's are frequently considered as the fourth generation of accelerator based light sources. In contrast to existing synchrotron radiation light sources which are mostly storage rings the FEL requirements on the electron beam quality in terms of low transverse emittance and small energy spread are so demanding that only linear accelerators can be used to provide the drive beam. In my one hour talk it was not possible to go much into mathematical details. The high gain FEL is therefore treated only qualitatively. For a thorough presentation of SASE FEL's I refer to the book \"The Physics of Free Electron Lasers\" by Saldin, Schneidmiller and Yurkov and to the lectures by J. Rossbach at the CERN Accelerator School on Synchrotron Radiation.",
"author_names": [
"N Andersen"
],
"corpus_id": 55884399,
"doc_id": "55884399",
"n_citations": 9,
"n_key_citations": 0,
"score": 0,
"title": "Free electron lasers: Charles A. Brau. Advances in Electronics and Electron Physics, Supplement 22 (Academic Press, Boston, 1990) pp. xi 420, softbound, US $39.95, ISBN 0 12 126000 3",
"venue": "",
"year": 1991
},
{
"abstract": "Edited by L. Marton New York and London: Academic Press Inc. Pp. x 341. Price 11.00 This latest edition of Advances in Electronics includes six survey papers entitled The Electron as a Chemical Entity, Problems of Photoconductivity, Strong Focusing Lenses, Hydrogen Thyratrons, Cerenkov Radiation at Microwave Frequencies, and High Power Axial Beam Tubes. More than one third of the book is given to Strong Focusing Lenses, by which is meant electron lenses consisting of 4 poles (or electrodes) arranged like the 4 poles of the stator of a d.c. machine and providing a magnetic (or electric) field which has constant radial gradient H/r (or E/r)",
"author_names": [
"M R Gavin"
],
"corpus_id": 125327783,
"doc_id": "125327783",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "Advances in Electronics and Electron Physics, Volume XIV",
"venue": "",
"year": 1961
},
{
"abstract": "",
"author_names": [
"Zhong Cun Chun Er"
],
"corpus_id": 117697269,
"doc_id": "117697269",
"n_citations": 8,
"n_key_citations": 0,
"score": 0,
"title": "Advances in Electronics and Electron Physics, Vol. 18, Academic Press. 1963, 342Ye 15x23cm, 5,000Yuan",
"venue": "",
"year": 1964
},
{
"abstract": "",
"author_names": [
""
],
"corpus_id": 54110443,
"doc_id": "54110443",
"n_citations": 8,
"n_key_citations": 0,
"score": 0,
"title": "Advances in Electronics and Electron Physics. Vol. 60",
"venue": "",
"year": 1983
},
{
"abstract": "Publisher Summary This chapter summarizes the technical and instrumental improvements of using the electronic camera and some of the scientific results. Recently, Prof. Lallemandi has succeeded in preparing S 1 photocathodes for use with the electronic camera, thus extending its wavelength coverage out into the infra red. The Lallemand electronic camera has been in use at the focus of the 20 in. Schmidt camera of the coude spectrograph of the 120 in. The electronic camera is presently used with an inefficient optical spectrograph system. There are a few types of observations in that the use of the image tube provides a real advantage over conventional methods. One of the limitations of the electronic camera is the existence of parasitic background, which, after a certain length of exposure, produces a relatively uniform blackening of the projected area of the photocathode on the plate. With continued refinement of the technique of preparing the tube and resultant improvements in the cleanliness of the interior of the system, it became apparent that at least one component of this background decreases with time after the cathode ampoule is broken and the cathode placed in its operating position. A new preparation stand has been constructed for the electronic camera, having a pumping system consisting of a sorption pump and a large ion pump instead of the usual diffusion pump and cold trap. The new system has the advantage of being virtually oil free and eliminates the danger of back streaming from the diffusion pump or cold trap.",
"author_names": [
"Merle F Walker"
],
"corpus_id": 117099243,
"doc_id": "117099243",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "Recent progress in the use of the Lallemand electronic camera in astronomical spectroscopy (Advances in Electronics and Electron Physics 1966)",
"venue": "",
"year": 1966
}
] |
Introduction to Spintronics | [
{
"abstract": "The Early History of Spin Spin The Bohr Planetary Model and Space Quantization The Birth of \"Spin\" The Stern Gerlach Experiment The Advent of Spintronics The Quantum Mechanics of Spin Pauli Spin Matrices The Pauli Equation and Spinors More on the Pauli Equation Extending the Pauli Equation the Dirac Equation The Time Independent Dirac Equation Appendix The Bloch Sphere The Spinor and the \"Qubit\" The Bloch Sphere Concept Evolution of a Spinor Spin 1/2 Particle in a Constant Magnetic Field: Larmor Precession Preparing to Derive the Rabi Formula The Rabi Formula The Density Matrix The Density Matrix Concept: Case of a Pure State Properties of the Density Matrix Pure Versus Mixed State Concept of the Bloch Ball Time Evolution of the Density Matrix: Case of Mixed State The Relaxation Times T1 and T2 and the Bloch Equations Spin Orbit Interaction Spin Orbit Interaction in a Solid Magneto Electric Sub Bands in Quantum Confined Structures in the Presence of Spin Orbit Interaction Dispersion Relations of Spin Resolved Magneto Electric Subbands and Eigenspinors in a Two Dimensional Electron Gas in the Presence of Spin Orbit Interaction Dispersion Relations of Spin Resolved Magneto Electric Subbands and Eigenspinors in a One Dimensional Electron Gas in the Presence of Spin Orbit Interaction Magnetic Field Perpendicular to Wire Axis and the Electric Field Causing Rashba Effect Eigenenergies of Spin Resolved Subbands and Eigenspinors in a Quantum Dot in the Presence of Spin Orbit Interaction Why Are the Dispersion Relations Important? The Three Types of Hall Effect Spin Relaxation Spin Relaxation Mechanisms Spin relaxation in a quantum dot Is the Effective Magnetic Field due to Spin Orbit Interaction Proportional to v or k? The Spin Galvanic Effect Exchange Interaction Identical Particles and the Pauli Exclusion Principle Hartree and Hartree Fock Approximations The Role of Exchange in Ferromagnetism The Heisenberg Hamiltonian Spin Transport in Solids The Drift Diffusion Model The Semiclassical Model Concluding Remarks Passive Spintronic Devices and Related Concepts Spin Valve Spin Injection Efficiency Hysteresis in Spin Valve Magnetoresistance Giant Magnetoresistance Spin Accumulation Spin Injection Across a Ferromagnet/Metal Interface Spin Injection in a Ferromagnet/Semiconductor/Ferromagnet Spin Valve Spin Extraction at a Ferromagnetic Contact/Semiconductor Interface Hybrid Spintronics Spin based transistors Spin Field Effect Transistors (SPINFET) Device Performance of SPINFETs Power Dissipation Estimates Other Types of SPINFETs The Importance of the Spin Injection Efficiency Transconductance, Gain, Bandwidth and Isolation Spin Bipolar Junction Transistors (SBJT) GMR based Transistors Concluding Remarks Monolithic Spintronics Monolithic Spintronics Reading and Writing Single Spin Single Spin Logic Energy Dissipation Issues Comparison Between Hybrid and Monolithic Spintronics Concluding Remarks Quantum Computing with Spins The Quantum Inverter Can the NAND Gate Be Switched Without Dissipating Energy? Universal Reversible Gate: The Toffoli Fredkin Gate A Matrix Quantum Gates Qubits Superposition States Quantum Parallelism Universal Quantum Gates A 2 Qubit \"Spintronic\" Universal Quantum Gate Conclusion A Quantum Mechanics Primer Blackbody Radiation and Quantization of Electromagnetic Energy The Concept of the Photon Wave Particle Duality and the De Broglie Wavelength Postulates of Quantum Mechanics Some Elements of Semiconductor Physics: Particular Applications in Nanostructures The Rayleigh Ritz Variational Procedure The Transfer Matrix Formalism",
"author_names": [
"Supriyo Bandyopadhyay",
"Marc Cahay"
],
"corpus_id": 118253704,
"doc_id": "118253704",
"n_citations": 152,
"n_key_citations": 16,
"score": 1,
"title": "Introduction to spintronics",
"venue": "",
"year": 2008
},
{
"abstract": "Abstract Spin based technologies, in the form of magnetic compasses, have existed for thousands of years. However, it is only in the last century that the concept of spin, as a pure quantum phenomenon, was established, paving the way for new applications exploiting its quantum mechanical properties. This chapter introduces the underlying mechanisms behind spin ordering in magnetic materials, particularly in two dimensional (2D) limit, and reviews historical milestones in the development of \"spintronics\" and electronic devices utilizing spin. Initially studied for fundamental physical interest, spintronic applications quickly came to prominence following the discovery of giant magnetoresistance and the rediscovery of tunneling magnetoresistance in metallic architectures. The desire to integrate these phenomena with the existing semiconductor based technologies used in the computing industry has inspired intensive study of spintronics within semiconductor materials. Notable developments include the spin field effect transistor and nonlocal device geometries. Following the discovery of novel electronic properties of graphene, there has been a drive to harness similar properties with the addition of spin control in van der Waals or 2D materials, resulting in several families of 2D magnetic materials known today.",
"author_names": [
"Wenqing Liu",
"Matthew T Bryan",
"Yongbing Xu"
],
"corpus_id": 213302161,
"doc_id": "213302161",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Introduction to spintronics and 2D materials",
"venue": "",
"year": 2020
},
{
"abstract": "Spintronics was born in 1988 with the discovery of GMR provided simultaneously by A. Fert and P. Grunberg and rewarded in 2007 with the Nobel Prize in Physics. This field has since been largely exploited on the market, for example it has been at the base of every hard disk read head. Spintronics field is extremely active and interesting from both a fundamental point of view and for technological applications. Currently, with the aim at new functionalities, there is an increased activity from materials research perspective to understand and develop spintronics devices using materials with new properties like carbon nanotubes, graphene, topological insulators and molecules. This chapter will start with the description of the electronic structure of ferromagnetic metals. The principle of a basic spintronic device will be then presented and finally, it will focus on magnetic tunnel junctions (MTJs) with a more detailed description of the tunneling magnetoresistance (TMR) effect proper to these systems.",
"author_names": [
"Marta Galbiati"
],
"corpus_id": 137869935,
"doc_id": "137869935",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Introduction to Spintronics",
"venue": "",
"year": 2016
},
{
"abstract": "",
"author_names": [
"Katsuaki Sato"
],
"corpus_id": 203031442,
"doc_id": "203031442",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Introduction to Spintronics",
"venue": "The Journal of The Institute of Electrical Engineers of Japan",
"year": 2019
},
{
"abstract": "This textbook is intended for students of engineering, material science, and/or applied physics to study the field of spintronics, otherwise known as electrogmagnetics. Provides the fundamental concepts in quantum mechanics and their applications to spintronic devices. It contains much algebra but it is not heavily theoretical. Students can follow the equations step by step. Each chapter contains problems and references to gain a deeper understanding of the subject matter.",
"author_names": [
"Junsaku Nitta"
],
"corpus_id": 33467737,
"doc_id": "33467737",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Introduction to Spintronics (Bandyopadhyay, S. and Cahay, M. [Book Review]",
"venue": "IEEE Nanotechnology Magazine",
"year": 2008
},
{
"abstract": "Spintronics refers to the study of the role played by electron spin in solid state physics.It is a new emerging field of basic and applied research in physics and engineering where neglected magnetic degree of freedom of an electron,which concerns spin polarization,spin relaxation,and corresponding applications of the electrons.Spintronics device by either adding the spin degree of freedom to conventional charge based electronic devices or using the spin alone has the potential advantages of increased data processing speed and integration densities compared with the conventional semiconductor devices,nonvolatility,and decreased electric power consumption.In this paper,spintronics in combination with spin valve sandwich,magnetic tunneling junction,and semiconductor spin electronics are briefly introduced;furthermore,its current development and applications are reviewed.",
"author_names": [
"Jia Hong-xuan"
],
"corpus_id": 139056268,
"doc_id": "139056268",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Brief introduction to spintronics and its development of study",
"venue": "",
"year": 2006
},
{
"abstract": "The past decade has witnessed a significant growth of new types of memory for nonvolatile data storage, as well as experimental devices for more efficient information processing [1] Quite a few of these are based on an intangible property of electrons peculiar to quantum mechanics [2] and, for this reason, such devices are identified as quantum devices[3] Many of these devices confine electrons to quantum scale dimensions, creating what are known as quantum dots. The quantum mechanical property known as electron spin not only is key to the functionality of quantum devices but also underlies permanent magnetism [4] Aligned spins suggest magnetism, whereas non aligned ones indicate that the material is not magnetic. An applied current generating a magnetic field can align or randomize spins, allowing spin based control.Spin can be traced back to the magnetic moment of atoms, since atomic magnetic moments are determined by electronic angular momenta. Accordingly, each individual electron within an atom has an angular momentum associated with its orbital motion, and an intrinsic, or spin angular momentum. The latter plays a major role in today's emerging information processing technologies [5] If, so far, electronic transistors have relied on the presence or absence of current to encode the ones and zeros of digital logic, a new type of transistors, dependent on spin, may do this more efficiently. Magnetic semiconductor quantum dots exploiting spin properties may lead to a new type of circuit based on magnetism instead of current flow.The existence of spin or, more importantly, the statistics associated with it has permitted inventive designs of spin based devices, particularly due to the Pauli exclusion principle that does not allow two electrons in an atom to occupy the same quantum state simultaneously [6] This connection between spin degrees of freedom and electron charge imposed by the Pauli exclusion principle has added a different level of practicality to quantum devices, creating a new branch of electronics termed spintronics (i.e.,spin electronics) As an emerging field, spintronics has already had various degrees of experimental success in proving that information can indeed be encoded, transported, and stored using both electron charge and spin. It is hoped that a successful spintronic transistor will be capable of retaining its logic state in the absence of current while requiring less power to switch a bit. As such, it would reduce the electrical power required by a computer chip by what many believe to be as much as 99%.Most practical challenges faced by spintronics, in particular those transistor type applications, fall broadly into three categories: injection of spin in an \"encoder\" control of spin transport through a unity usually termed a \"spacer\" and selective detection of spin in the final element or \"decoder\" Another issue is temperature dependence and reliability. A practical device is expected to function at room temperature or above. However, many materials are ferromagnetic below certain temperatures. That means they retain their magnetic state in the absence of an applied field but lose that characteristic when they warm up. Therefore, many of these spintronic technologies are still in a research stage, and have yet to be commercialized. These topics will be addressed in this chapter, while particularly emphasizing developments where a significant amount of research seems to be concentrated nowadays.",
"author_names": [
"Carmen-Gabriela Stefanita"
],
"corpus_id": 124178630,
"doc_id": "124178630",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Introduction to Spintronics",
"venue": "",
"year": 2012
},
{
"abstract": "",
"author_names": [
"Supriyo Datta"
],
"corpus_id": 138721875,
"doc_id": "138721875",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Nanoelectronic Devices, With an Introduction to Spintronics (Lecture Notes)",
"venue": "",
"year": 2010
},
{
"abstract": "",
"author_names": [
"Supriyo Datta",
"Mark S Lundstrom"
],
"corpus_id": 138382950,
"doc_id": "138382950",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Nanoelectronic Devices, With an Introduction to Spintronics",
"venue": "",
"year": 2010
},
{
"abstract": "We review the progress and future possibilities in the emerging area of molecular spintronics. We first provide an overview of the different transport regimes in which electronic nanodevices can operate, then briefly overview the important characteristics of molecular magnetic materials that can be useful for application in spintronics and we eventually present several schemes to include such systems into spintronic nanodevices. We hightlight the importance of a chemical approach to the area, and in the last section we showcase some approaches to the creation of hybrids made of carbon nanostructures and molecular magnets, which are gaining increasing attention.",
"author_names": [
"Shan Jiang",
"Karin Goss",
"Christian Cervetti",
"Lapo Bogani"
],
"corpus_id": 93520884,
"doc_id": "93520884",
"n_citations": 25,
"n_key_citations": 1,
"score": 0,
"title": "An introduction to molecular spintronics",
"venue": "Science China Chemistry",
"year": 2012
}
] |
Production control in semiconductor manufacturing with time constraints | [
{
"abstract": "In this paper, production of lots under time constraints in a semiconductor wafer fabrication is investigated. A time constraint covers a sequence of process steps and has a maximum time that lots must spend in these steps. Lots which violate a recommended time constraint have to be scrapped or reprocessed. Accordingly, controlling the entrance of lots in a time constraint is critical in semiconductor fabrication. An approach is developed to estimate whether a given lot may satisfy time constraints or not. Some numerical experiments are presented with industrial data.",
"author_names": [
"Rezvan Sadeghi",
"Stephane Dauzere-Peres",
"Claude Yugma",
"Guillaume Lepelletier"
],
"corpus_id": 40140226,
"doc_id": "40140226",
"n_citations": 17,
"n_key_citations": 1,
"score": 1,
"title": "Production control in semiconductor manufacturing with time constraints",
"venue": "2015 26th Annual SEMI Advanced Semiconductor Manufacturing Conference (ASMC)",
"year": 2015
},
{
"abstract": "This paper investigates and compares different control mechanisms for timelink areas in a semiconductor manufacturing line with tool downs. Timelinks are time constraints between consecutive process steps. The goal of this paper is to search for good and practicable control mechanisms, that determine optimal release dates for lots in front of a timelink area with a minimum of time constraint violations. To evaluate good control mechanisms, this paper will investigate risk factors which are based especially on failure probability of tools, with the aid of survival analysis, at the end of a timelink area. These risk factors will be included in a mixed integer program (MIP) together with the time constraints. To test the developed scheduling method the MIP will be simulated in a hybrid model (symbioses of simulation and a mathematical solver) under the aspect of rolling horizon planning with a simulation of unscheduled tool downs. On the basis of the failure probability there will be also different capacity calculations to derive and compare dispatching rules. The dispatching rules are tested by a discrete simulation model that considers also unscheduled tool downs. At last the results of the MIP are compared with the prepared dispatching rules.",
"author_names": [
"Christian Maleck",
"Tobias Eckert"
],
"corpus_id": 22721538,
"doc_id": "22721538",
"n_citations": 5,
"n_key_citations": 3,
"score": 0,
"title": "A comparison of control methods for production areas with time constraints and tool interruptions in semiconductor manufacturing",
"venue": "2017 40th International Spring Seminar on Electronics Technology (ISSE)",
"year": 2017
},
{
"abstract": "In this paper we will present a multi stage scheduling approach to generate robust schedules for a challenging aspect of semiconductor manufacturing called time link areas. A time link is a technologically induced time constraint between one or more consecutive process steps requiring the process steps to be executed within a predefined time window. Time links are often introduced to control contamination or unwanted oxidation. Violating time link constraints may lead to extra effort due to additional rework steps and may have negative yield impact or may even, result in scrap.",
"author_names": [
"Christian Maleck",
"Gottfried Nieke",
"Karlheinz Bock",
"Detlef Pabst",
"Meinhard Schulze",
"Marcel Stehli"
],
"corpus_id": 199508860,
"doc_id": "199508860",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "A Robust Multi Stage Scheduling Approach for Semiconductor Manufacturing Production Areas with Time Contraints",
"venue": "2019 30th Annual SEMI Advanced Semiconductor Manufacturing Conference (ASMC)",
"year": 2019
},
{
"abstract": "This research develops production control methods for multi product systems under process queue time (PQT) constraints.A single flexible upstream workstation and multiple dedicated downstream workstations are considered.Under the PQT constraint, jobs are scrapped if the waiting time before a queue is longer than a pre defined upper limit.An innovative multiple product admission control heuristic is developed using Markov decision processes.The proposed MPAC method reduces production costs and scrap counts by 33.8% and 59.5% in our numerical study. In a multi product manufacture system, the complexity of production control increases. Because multiple products are competing for limited resource, managers need to dynamically adjust production priority based on customer demand and distribution of work in processes (WIP) The production control in multi product system becomes even more complicated when process queue time (PQT) constraints exist. Under PQT constraints, administrators setup upper limits for the waiting time between specific manufacturing steps to ensure quality of products. This upper limit of waiting time makes dynamic production control very challenging.The objective of this paper is to develop production control methods for multi product systems subject to PQT constraints. However, it is computationally infeasible to solve multiple product problems in a single dynamic optimization model, and we therefore first formulate a single product admission control problems using Markov decision processes (MDP) Based on observations from the single product MDP model, an innovative multiple product admission control (MPAC) heuristic is developed. In simulation study, we compare the performance of MPAC with other popular dispatching methods in literature. Compare to other control methods in literature, the proposed (MPAC) method can reduce production costs by at least 33.8% and reduce scrap count by at least 59.5% in average.",
"author_names": [
"Cheng-Hung Wu",
"Wen-Chi Chien",
"Ya-Tang Chuang",
"Yu-Ching Cheng"
],
"corpus_id": 5364240,
"doc_id": "5364240",
"n_citations": 8,
"n_key_citations": 0,
"score": 0,
"title": "Multiple product admission control in semiconductor manufacturing systems with process queue time (PQT) constraints",
"venue": "Comput. Ind. Eng.",
"year": 2016
},
{
"abstract": "Reinforcement learning (RL) offers promising opportunities to handle the ever increasing complexity in managing modern production systems. We apply a Q learning algorithm in combination with a process based discrete event simulation in order to train a self learning, intelligent, and autonomous agent for the decision problem of order dispatching in a complex job shop with strict time constraints. For the first time, we combine RL in production control with strict time constraints. The simulation represents the characteristics of complex job shops typically found in semiconductor manufacturing. A real world use case from a wafer fab is addressed with a developed and implemented framework. The performance of an RL approach and benchmark heuristics are compared. It is shown that RL can be successfully applied to manage order dispatching in a complex environment including time constraints. An RL agent with a gain function rewarding the selection of the least critical order with respect to time constraints beats heuristic rules strictly by picking the most critical lot first. Hence, this work demonstrates that a self learning agent can successfully manage time constraints with the agent performing better than the traditional benchmark, a time constraint heuristic combining due date deviations and a classical first in first out approach.",
"author_names": [
"Thomas Altenmuller",
"Tillmann Stuker",
"Bernd Waschneck",
"Andreas Kuhnle",
"Gisela Lanza"
],
"corpus_id": 219968163,
"doc_id": "219968163",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Reinforcement learning for an intelligent and autonomous production control of complex job shops under time constraints",
"venue": "",
"year": 2020
},
{
"abstract": "Abstract Waiting time constraints between two processes are one of common scheduling requirements in many production systems, such as semiconductor, automotive, food, and battery manufacturing. When the time constraints are introduced, quality inspection should be carried out on parts that have exceeded a given time limit and such parts are subject to be re processed or scrapped, which incurs additional expenses and efforts. Therefore, the foremost goal is to maximize yield, which is defined by the production rate of parts that do not violate the time constraints. In this paper, we present a mathematical model of Bernoulli production lines to evaluate yield and examine its properties with respect to time constraints, buffer capacity, and machine reliability. System properties such as monotonicity and asymptotic characteristics are analyzed. With the analysis results, an efficient algorithm to design an optimal buffer capacity is developed. It is shown that, in contrast to traditional production lines, there is no monotonicity of yield on the reliability of an upstream machine; that is, an upstream machine becoming more reliable does not always contribute to increasing yield. Therefore, optimal control policies are presented to control the upstream machine for maximal yield. Finally, a case study is introduced to illustrate the applicability of the method.",
"author_names": [
"Jun-Ho Lee",
"Cong Zhao",
"Jingshan Li",
"C T Papadopoulos"
],
"corpus_id": 115836500,
"doc_id": "115836500",
"n_citations": 14,
"n_key_citations": 2,
"score": 0,
"title": "Analysis, design, and control of Bernoulli production lines with waiting time constraints",
"venue": "",
"year": 2018
},
{
"abstract": "Semiconductor manufacturing processes often come with stringent requirements for product quality. In order to satisfy these requirements, time window constraints have been imposed. Typically, violation of the time windows can result in a lot being either reworked or scrapped. The presence of overlapped time window constraints renders the control of production lines very challenging as it involves managing the production process of many lots across multiple workstations. We study the performance of a production line with deterministic service times and predetermined, overlapped time windows. We solve the {P|r_{j}|C_{\\max problem to estimate the queue time at each workstation, and develop an algorithm to decide whether a new lot can be released for processing at its first workstation so as to meet all time window constraints.",
"author_names": [
"MengChang Wang",
"Sandeep Srivathsan",
"Edward Huang",
"Kan Wu"
],
"corpus_id": 13739422,
"doc_id": "13739422",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "Job Dispatch Control for Production Lines With Overlapped Time Window Constraints",
"venue": "IEEE Transactions on Semiconductor Manufacturing",
"year": 2018
},
{
"abstract": "Scheduling optimization in semiconductor manufacturing is always a crucial task in production performance indicators such as machine utilization, cycle time and delivery times. With the increasing complexity of fabrication techniques and scales, scheduling and control activities are inevitably confronted with each other and shall be integrated correspondingly. In particular scheduling and control are mutually dependent as control requires decisions from schedules, and scheduling should take control information into account. Based on a literature survey, we propose a general review and an outlook of the expected improvements related to binding scheduling decisions and information/constraints coming from Advanced Process Control systems in semiconductor manufacturing. Potential issues and tasks concerning this integration are addressed in this paper in order to stimulate more work in research and industrial practices.",
"author_names": [
"Claude Yugma",
"Jakey Blue",
"Stephane Dauzere-Peres",
"Philippe Vialletelle"
],
"corpus_id": 38251379,
"doc_id": "38251379",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Integration of scheduling and advanced process control in semiconductor manufacturing: review and outlook",
"venue": "CASE",
"year": 2014
},
{
"abstract": "Abstract It is commonly observed in the food industry, battery production, automotive paint shop, and semiconductor manufacturing that an intermediate product's residence time in the buffer within a production line is controlled by a time window to guarantee product quality. There is typically a minimum time limit reflected by a part's travel time or process requirement. Meanwhile, these intermediate parts are prevented from staying in the buffer for too long by an upper time limit, exceeding which a part will be scrapped or need additional treatment. To increase production throughput and reduce scrap, one needs to control machines' working mode according to real time system information in the stochastic production environment, which is a difficult problem to solve, due to the system's complexity. In this article, we propose a novel decomposition based control approach by decomposing a production system into small scale subsystems based on domain knowledge and their structural relationship. An iterative aggregation procedure is then used to generate a production control policy with convergence guarantee. Numerical studies suggest that the decomposition based control approach outperforms general purpose reinforcement learning method by delivering significant system performance improvement and substantial reduction on computation overhead.",
"author_names": [
"Feifan Wang",
"Feng Ju"
],
"corpus_id": 225389413,
"doc_id": "225389413",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Decomposition based real time control of multi stage transfer lines with residence time constraints",
"venue": "IISE Trans.",
"year": 2021
},
{
"abstract": "This paper presented solutions respond to three issues of scheduling of semiconductor manufacturing. As the First, we introduced how to apply SCKB REFS rule, which is the optimal re entrant flow dispatching for maximizing throughput of quality product in Q time constraints processes, to the case of more than two different re entrant flows. The performance of SCKB REFS rule is evaluated by comparing with typical rules, FCFS CT and LPFS CT, in case that three different flows (i.e. specifications) share the same production tools. SCKB REFS rule achieved the best performance in terms of mean cycle time and the throughput ratio in every traffic intensity as the result.",
"author_names": [
"Akihiro Kobayashi",
"Takahiro Kuno",
"Sumika Arima"
],
"corpus_id": 44736959,
"doc_id": "44736959",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Re entrant flow control in Q time constraints processes for actual applications",
"venue": "2013 e Manufacturing Design Collaboration Symposium (eMDC)",
"year": 2013
}
] |
Thermal Management of Electronics: A review of Literature | [
{
"abstract": "Due to rapid growth in semiconductor technology, there is a continuous increase of the system power and the shrinkage of size. This resulted in inevitable challenges in the field of thermal management of electronics to maintain the desirable operating temperature. The present paper reviews the literature dealing with various aspects of cooling methods. Included are papers on experimental work on analyzing cooling technique and its stability, numerical modeling, natural convection, and advanced cooling methods. The issues of thermal management of electronics, development of new effective cooling schemes by using advanced materials and manufacturing methods are also enumerated in this paper.",
"author_names": [
"Sundaram Shanmuga Anandan",
"Velraj Ramalingam"
],
"corpus_id": 54606140,
"doc_id": "54606140",
"n_citations": 166,
"n_key_citations": 12,
"score": 1,
"title": "Thermal management of electronics: A review of literature",
"venue": "",
"year": 2008
},
{
"abstract": "Abstract Thermal interface materials (TIMs) are used extensively to improve thermal conduction across two mating parts. They are particularly crucial in electronics thermal management since excessive junction to ambient thermal resistances can cause elevated temperatures which can negatively influence device performance and reliability. Of particular interest to electronic package designers is the thermal resistance of the TIM layer at the end of its design life. Estimations of this allow the package to be designed to perform adequately over its entire useful life. To this end, TIM reliability studies have been performed using accelerated stress tests. This paper reviews the body of work which has been performed on TIM reliability. It focuses on the various test methodologies with commentary on the results which have been obtained for the different TIM materials. Based on the information available in the open literature, a test procedure is proposed for TIM selection based on beginning and end of life performance.",
"author_names": [
"Jens Due",
"A J Robinson"
],
"corpus_id": 110737759,
"doc_id": "110737759",
"n_citations": 104,
"n_key_citations": 4,
"score": 0,
"title": "Reliability of thermal interface materials: A review",
"venue": "",
"year": 2013
},
{
"abstract": "The thermal management of magnetic components for power electronics is crucial to ensure their reliability. However, conventional thermal models for magnetic components are known to have either poor accuracy or excessive complexity. Contrary to these models, the use of Thermal Resistance Matrices is proposed in this paper instead, which combine both accuracy and simplicity. They are usually used to characterize semiconductor devices, but not for magnetic components. The guidelines to apply Thermal Resistance Matrices for magnetic components are discussed in detail. The accuracy of this model is validated by 3D FEA simulations and experimental results, showing an absolute error lower than 5 C and a relative error between 6.4% and 3.9% which is outstanding compared to the carried out literature review.",
"author_names": [
"Guillermo Salinas",
"Juan A Serrano-Vargas",
"Javier Munoz-Anton",
"Pedro Alou"
],
"corpus_id": 236356328,
"doc_id": "236356328",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Thermal Resistance Matrix Extraction from Finite Element Analysis for High Frequency Magnetic Components",
"venue": "",
"year": 2021
},
{
"abstract": "Dielectric materials with high thermal conductivity (TC) can enable disruptive performance enhancement in the areas of electronics packaging, thermal management, energy storage, cabling, and heat sinks. There have been widespread global efforts over the past decade on developing novel nanocomposite dielectric materials. As a baseline, legacy polymers and epoxies used in the abovementioned applications have very low thermal conductivities ranging from 0.1 0.5 \\text{W}\\cdot \\text{m} 1} \\cdot \\text{K} 1} Recent advances have led to the commercial availability of polymeric materials with thermal conductivities approaching 10 \\text{W}\\cdot \\text{m} 1} \\cdot \\text{K} 1} Importantly, several fundamental studies report novel nanocomposites with thermal conductivities >50\\\\text{W}\\cdot \\text{m} 1} \\cdot \\text{K} 1} This article summarizes progress in the development of such materials with a focus on developments that show promise for improved practical dielectrics. This review highlights that high TC alone is inadequate to characterize the suitability of any material for the above applications. Other thermal properties, such as thermal diffusivity, glass transition temperature, and the ratio of the in plane to out of plane TC, are important to quantify the thermal performance of novel nanocomposites. In addition, characterization and understanding of mechanical properties (coefficient of thermal expansion (CTE) tensile strength and elastic modulus) and electrical properties (dielectric strength and dielectric permittivity) are critical for holistic multifunctional assessments of these materials. There are other parameters and properties that influence performance, life, and manufacturability, such as viscosity and moisture absorption. This study reviews all the above aspects of nanocomposite dielectric materials reported in the literature. More specifically, we analyze various filler polymer combinations, and the influence of approaches to incorporate fillers in the polymer on the thermal, mechanical, and electrical properties. While the addition of fillers leads to huge enhancements in TC, the TC is highly anisotropic, with out of plane TC lower than in plane TC by an order of magnitude. It is seen that most present day materials are still inadequate for future applications due to their low glass transition temperatures; specific promising materials are highlighted. While the addition of fillers reduces the CTE, further reduction is needed to favorably improve the mechanical performance of these materials. While the electrical insulating properties of these composite materials are adequate, there is very little data reported on other electrical properties. In summary, while there is an understandable focus on enhancing the TC, other properties are underreported, and there is insufficient information to support the assessment of most novel materials for practical applications. Overall, this study summarizes the state of the art dielectric nanocomposites and outlines directions for future research to bridge the gap between basic materials science and applications.",
"author_names": [
"Manojkumar Lokanathan",
"Palash V Acharya",
"Abdelhamid Ouroua",
"Shannon Strank",
"Robert E Hebner",
"Vaibhav Bahadur"
],
"corpus_id": 236180498,
"doc_id": "236180498",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Review of Nanocomposite Dielectric Materials With High Thermal Conductivity",
"venue": "Proceedings of the IEEE",
"year": 2021
},
{
"abstract": "Bipolar disorder (BD) is a chronic and disabling psychiatric condition that is linked to significant disability and psychosocial impairment. Although current neuropsychological, molecular, and neuroimaging evidence support the existence of neuroprogression and its effects on the course and outcome of this condition, whether and to what extent neuroprogressive changes may impact the illness trajectory is still poorly understood. Thus, this selective review was aimed toward comprehensively and critically investigating the link between BD and neurodegeneration based on the currently available evidence. According to the most relevant findings of the present review, most of the existing neuropsychological, neuroimaging, and molecular evidence demonstrates the existence of neuroprogression, at least in a subgroup of BD patients. These studies mainly focused on the most relevant effects of neuroprogression on the course and outcome of BD. The main implications of this assumption are discussed in light of specific shortcomings/limitations, such as the inability to carry out a meta analysis, the inclusion of studies with small sample sizes, retrospective study designs, and different longitudinal investigations at various time points.",
"author_names": [
"Gianluca Serafini",
"Matteo Pardini",
"Fiammetta Monacelli",
"Beatrice Orso",
"Nicola Girtler",
"Andrea Brugnolo",
"Mario Amore",
"Flavio Nobili"
],
"corpus_id": 232112108,
"doc_id": "232112108",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Neuroprogression as an Illness Trajectory in Bipolar Disorder: A Selective Review of the Current Literature",
"venue": "Brain sciences",
"year": 2021
},
{
"abstract": "BackgroundLaparoscopic sleeve gastrectomy (LSG) is a common weight loss operation that is increasingly being managed on an outpatient or overnight stay basis. The aim of this systematic review was to evaluate the available literature and develop recommendations for optimal pain management after LSG.MethodsA systematic review utilizing preferred reporting items for systematic reviews and meta analysis with PROcedure SPECific Postoperative Pain ManagemenT methodology was undertaken. Randomized controlled trials (RCTs) published in the English language from inception to September 2018 assessing postoperative pain using analgesic, anesthetic, and surgical interventions were identified from MEDLINE, EMBASE and Cochrane Databases.ResultsSignificant heterogeneity was identified in the 18 RCTs included in this systematic review. Gabapentinoids and transversus abdominis plane blocks reduced LSG postoperative pain. There was limited procedure specific evidence of analgesic effects for acetaminophen, non steroidal anti inflammatory drugs, dexamethasone, magnesium, and tramadol in this setting. Inconsistent evidence was found in the studies investigating alpha 2 agonists. No evidence was found for intraperitoneal local anesthetic administration or single port laparoscopy.ConclusionsThe literature to recommend an optimal analgesic regimen for LSG is limited. The pragmatic view supports acetaminophen and a non steroidal anti inflammatory drug, with opioids as rescue analgesics. Gabapentinoids should be used with caution, as they may amplify opioid induced respiratory depression. Although transversus abdominis plane blocks reduced pain, port site infiltration may be considered instead, as it is a simple and inexpensive approach that provides adequate somatic blockade. Further RCTs are required to confirm the influence of the recommended analgesic regimen on postoperative pain relief.",
"author_names": [
"Hoani Macfater",
"Weisi Xia",
"Sanket Srinivasa",
"Andrew G Hill",
"Marc Van de Velde",
"Girsh P Joshi",
"On Behalf Of D C V A S Collaborators"
],
"corpus_id": 59603208,
"doc_id": "59603208",
"n_citations": 10,
"n_key_citations": 0,
"score": 0,
"title": "Evidence Based Management of Postoperative Pain in Adults Undergoing Laparoscopic Sleeve Gastrectomy",
"venue": "World Journal of Surgery",
"year": 2019
},
{
"abstract": "PurposeThe aim of this project was to develop clinical practice guidelines on the use of antimicrobials, mucosal coating agents, anesthetics, and analgesics for the prevention and management of oral mucositis (OM) in cancer patients.MethodsA systematic review of the available literature was conducted. The body of evidence for the use of each agent, in each setting, was assigned a level of evidence. Based on the evidence level, one of the following three guideline determinations was possible: recommendation, suggestion, or no guideline possible.ResultsA recommendation was developed in favor of patient controlled analgesia with morphine in hematopoietic stem cell transplant (HSCT) patients. Suggestions were developed in favor of transdermal fentanyl in standard dose chemotherapy and HSCT patients and morphine mouth rinse and doxepin rinse in head and neck radiation therapy (H&N RT) patients. Recommendations were developed against the use of topical antimicrobial agents for the prevention of mucositis. These included recommendations against the use of iseganan for mucositis prevention in HSCT and H&N RT and against the use of antimicrobial lozenges (polymyxin tobramycin amphotericin B lozenges/paste and bacitracin clotrimazole gentamicin lozenges) for mucositis prevention in H&N RT. Recommendations were developed against the use of the mucosal coating agent sucralfate for the prevention or treatment of chemotherapy induced or radiation induced OM. No guidelines were possible for any other agent due to insufficient and/or conflicting evidence.ConclusionAdditional well designed research is needed on prevention and management approaches for OM.",
"author_names": [
"Deborah P Saunders",
"Joel B Epstein",
"S Elad",
"Justin Allemano",
"Paolo Bossi",
"Marianne D Wetering",
"Nikhil G Rao",
"C M J Potting",
"K K F Cheng",
"Annette Freidank",
"Michael T Brennan",
"Joanne M Bowen",
"Kristopher Dennis",
"Rajesh V Lalla",
"For the Mucositis Study Group of the Multinational Ass Oncology"
],
"corpus_id": 1492490,
"doc_id": "1492490",
"n_citations": 124,
"n_key_citations": 3,
"score": 0,
"title": "Systematic review of antimicrobials, mucosal coating agents, anesthetics, and analgesics for the management of oral mucositis in cancer patients",
"venue": "Supportive Care in Cancer",
"year": 2013
},
{
"abstract": "PurposeThe aim of this study was to review the available literature and define clinical practice guidelines for the use of natural agents for the prevention and treatment of oral mucositis.MethodsA systematic review was conducted by the Mucositis Study Group of the Multinational Association of Supportive Care in Cancer/International Society for Oral Oncology. The body of evidence for each intervention, in each cancer treatment setting, was assigned an evidence level. Based on the evidence level, one of the following three guideline determinations was possible: recommendation, suggestion, and no guideline possible.ResultsA total of 49 papers across 15 interventions were examined. A new suggestion was developed in favor of systemic zinc supplements administered orally in the prevention of oral mucositis in oral cancer patients receiving radiation therapy or chemoradiation (Level III evidence) A recommendation was made against the use of intravenous glutamine for the prevention of oral mucositis in patients receiving high dose chemotherapy prior to hematopoietic stem cell transplant (Level II evidence) No guideline was possible for any other agent, due to inadequate and/or conflicting evidence.ConclusionsOf the various natural agents reviewed here, the available evidence supported a guideline only for two agents: a suggestion in favor of zinc and a recommendation against glutamine, in the treatment settings listed above. Well designed studies of other natural agents are warranted.",
"author_names": [
"Noam Yarom",
"Anura Ariyawardana",
"Allan J Hovan",
"Andrei Barasch",
"Virginia Jarvis",
"Siri Beier Jensen",
"Yehuda Zadik",
"S Elad",
"Joanne M Bowen",
"Rajesh V Lalla",
"For the Mucositis Study Group of the Multinational Ass Oncology"
],
"corpus_id": 10920964,
"doc_id": "10920964",
"n_citations": 85,
"n_key_citations": 7,
"score": 0,
"title": "Systematic review of natural agents for the management of oral mucositis in cancer patients",
"venue": "Supportive Care in Cancer",
"year": 2013
},
{
"abstract": "PurposeThe aim of this study was to review the available literature and define clinical practice guidelines for the use of agents for the prevention and treatment of gastrointestinal mucositis.MethodsA systematic review was conducted by the Mucositis Study Group of the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) The body of evidence for each intervention, in each cancer treatment setting, was assigned an evidence level. Based on the evidence level, one of the following three guideline determinations was possible: recommendation, suggestion, and no guideline possible.ResultsA total of 251 clinical studies across 29 interventions were examined. Panel members were able to make one new evidence based negative recommendation; two new evidence based suggestions, and one evidence based change from previous guidelines. Firstly, the panel recommends against the use of misoprostol suppositories for the prevention of acute radiation induced proctitis. Secondly, the panel suggests probiotic treatment containing Lactobacillus spp. may be beneficial for prevention of chemotherapy and radiotherapy induced diarrhea in patients with malignancies of the pelvic region. Thirdly, the panel suggests the use of hyperbaric oxygen as an effective means in treating radiation induced proctitis. Finally, new evidence has emerged which is in conflict with our previous guideline surrounding the use of systemic glutamine, meaning that the panel is unable to form a guideline. No guideline was possible for any other agent, due to inadequate and/or conflicting evidence.ConclusionsThis updated review of the literature has allowed new recommendations and suggestions for clinical practice to be reached. This highlights the importance of regular updates.",
"author_names": [
"Rachel J Gibson",
"Dorothy Keefe",
"Rajesh V Lalla",
"Emma H Bateman",
"N M A Blijlevens",
"Margot Fijlstra",
"Emily E King",
"Andrea M Stringer",
"Walter J F M van der Velden",
"Roger Yazbeck",
"S Elad",
"Joanne M Bowen",
"For the Mucositis Study Group of the Multinational Ass Oncology"
],
"corpus_id": 12797539,
"doc_id": "12797539",
"n_citations": 164,
"n_key_citations": 2,
"score": 0,
"title": "Systematic review of agents for the management of gastrointestinal mucositis in cancer patients",
"venue": "Supportive Care in Cancer",
"year": 2012
},
{
"abstract": "Purpose of ReviewThis review aims to summarize the type 1 diabetes (T1D) and weight literature with an emphasis on barriers associated with weight management, the unique T1D specific factors that impact weight loss success, maladaptive and adaptive strategies for weight loss, and interventions to promote weight loss.Recent FindingsWeight gain is associated with intensive insulin therapy. Overweight and obese weight status in individuals with T1D is higher than the general population and prevalence is rising. A variety of demographic (e.g. female sex) clinical (e.g. greater insulin needs) environmental (e.g. skipping meals) and psychosocial (e.g. depression, stress) factors are associated with overweight/obese weight status in T1D. Fear of hypoglycemia is a significant barrier to engagement in physical activity. Studies evaluating adaptive weight loss strategies in people with T1D are limited.SummaryThere is a growing literature highlighting the prevalence and seriousness of overweight and obesity among both youth and adults with T1D. There is an urgent need to develop evidence based weight management guidelines and interventions that address the unique concerns of individuals with T1D and that concurrently address glycemic control.",
"author_names": [
"Kimberly A Driscoll",
"Karen D Corbin",
"David M Maahs",
"Richard E Pratley",
"Franziska K Bishop",
"Anna R Kahkoska",
"Korey K Hood",
"Elizabeth J Mayer-Davis",
"on behalf of the Advancing Care for Type 1 Diabetes a Network"
],
"corpus_id": 5111522,
"doc_id": "5111522",
"n_citations": 27,
"n_key_citations": 0,
"score": 0,
"title": "Biopsychosocial Aspects of Weight Management in Type 1 Diabetes: a Review and Next Steps",
"venue": "Current Diabetes Reports",
"year": 2017
}
] |
Zigbee Wireless Networks and Transceivers | [
{
"abstract": "ZigBee is a short range wireless networking standard backed by such industry leaders as Motorola, Texas Instruments, Philips, Samsung, Siemens, Freescale, etc. It supports mesh networking, each node can transmit and receive data, offers high security and robustness, and is being rapidly adopted in industrial, control/monitoring, and medical applications. This book will explain the ZigBee protocol, discuss the design of ZigBee hardware, and describe how to design and implement ZigBee networks. The book has a dedicated website for the latest technical updates, ZigBee networking calculators, and additional materials. Dr. Farahani is a ZigBee system engineer for Freescale semiconductors Inc.Table of ContentsChapter 1: ZigBee BasicsChapter 2: ZigBee IEEE 802.15.4 Networking ExamplesChapter 3: ZigBee IEEE 802.15.4 Protocol LayersChapter 4: Transceiver RequirementsChapter 5: RF Propagation, Antennas, and Regulatory RequirementsChapter 6: Battery Life AnalysisChapter 7: Location Estimating Using ZigBee Chapter 8: ZigBee CoexistenceChapter 9: Related TechnologiesAppendicesKEY FEATURES* Provides a comprehensive overview of ZigBee technology and networking, from RF/physical layer considerations to application layer development. Discusses ZigBee security features such as encryption. Describes how ZigBee can be used in location detection applications. Explores techniques for ZigBee co existence with other wireless technologies such as 802.11 and Bluetooth.",
"author_names": [
"Shahin Farahani"
],
"corpus_id": 108112680,
"doc_id": "108112680",
"n_citations": 571,
"n_key_citations": 85,
"score": 1,
"title": "ZigBee Wireless Networks and Transceivers",
"venue": "",
"year": 2008
},
{
"abstract": "Agriculture determines the economic growth of nation and is known to be its backbone. Farmers, researchers, and technical manufacturers are joining efforts to find more efficient solutions for solving various different problems in agriculture to improve current production and processes Precision. The proposed framework for precision agriculture employs low cost environmental sensors, an Arduino Uno prototyping board and a pair of wireless transceivers (XBee ZB S2) along with actuating circuit to provide automated irrigation and monitoring of crops. The proposed prototype uses XBee protocol which is based on ZigBee technology .The important characteristics of ZigBee technology favorable for precision agriculture are; low data rate, low power consumption and larger coverage area. Thus, due to aforesaid characteristics, ZigBee technology happens to be the first choice for implementing precision agriculture. The newly emerging technology i.e. Wireless Sensor Networks spread rapidly into many field's like medical, habitat monitoring, bio technology etc.",
"author_names": [
"Shanthi D L",
"Mohd Aiman Jaffer",
"Harshitha Neelakanta",
"M Sowmya",
"M Dinesh"
],
"corpus_id": 219683453,
"doc_id": "219683453",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Comparative Analysis of Smart Irrigation and Crop Prediction using Wireless Sensor Networks and Machine Learning",
"venue": "",
"year": 2020
},
{
"abstract": "This paper presents on the results of radiation studies for three commonly used wireless sensor nodes based on the following protocols: ZigBee, WirelessHART, ISA 100.11a, and network devices built with commercial off the shelf (COTS) components. The level of radiation considered is at par with that experienced at Fukushima Daiichi Nuclear Power Plant after the accident. An experimental setup is developed to monitor behaviors of each wireless device and network real time under the 60 Co gamma radiator at The Ohio State University Nuclear Reactor Lab (OSU NRL) The experimental results have indicated that the performance of the communication channels and wireless signal parameters do not degrade significant under such radiation. However, all the tested devices and networks can only survive for several hours under the high dose rate condition (20 K Rad/h) The results of these experimental studies have provided useful references to those who design and manufacture COTS based wireless monitoring systems for use in high level radiation environments.",
"author_names": [
"Q Huang",
"J Jiang",
"Y Q Deng"
],
"corpus_id": 213542672,
"doc_id": "213542672",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Comparative Evaluation of Three Wireless Sensor Network Transceivers in a High Radiation Environment",
"venue": "",
"year": 2020
},
{
"abstract": "With the emergence of connected and autonomous vehicles, sensors are increasingly deployed within cars to support new functionalities. Traffic generated by these sensors congest traditional intra car networks, such as CAN buses. Furthermore, the large amount of wires needed to connect sensors makes it harder to design cars in a modular way. To alleviate these limitations, we propose, simulate, and implement a hybrid wired/wireless architecture, in which each node is connected to either a wired interface or a wireless interface or both. Specifically, we propose a new protocol, called Hybrid Backpressure Collection Protocol (Hybrid BCP) to efficiently collect data from sensors in intra car networks. Hybrid BCP is backward compatible with the CAN bus technology, and builds on the BCP protocol, designed for wireless sensor networks. We theoretically prove that an idealized version of Hybrid BCP achieves optimal throughput. Our testbed implementation, based on CAN and ZigBee transceivers, demonstrates the load balancing and routing functionalities of Hybrid BCP and its resilience to DoS attacks and wireless jamming attacks. We further provide simulation results, obtained with the ns 3 simulator and based on real intra car RSSI traces, that compare between the performance of Hybrid BCP and a tree based data collection protocol. Notably, the simulations show that Hybrid BCP outperforms the tree based protocol on throughput by 12 percent. The results also show that Hybrid BCP maintains high packet delivery rate and low packet delay for safety critical sensors that are directly connected to the sink through wire.",
"author_names": [
"Wei Si",
"David Starobinski",
"Moshe Laifenfeld"
],
"corpus_id": 53469268,
"doc_id": "53469268",
"n_citations": 11,
"n_key_citations": 0,
"score": 0,
"title": "A Robust Load Balancing and Routing Protocol for Intra Car Hybrid Wired/Wireless Networks",
"venue": "IEEE Transactions on Mobile Computing",
"year": 2019
},
{
"abstract": "In this paper, we study proper routing protocols for border surveillance missions using wireless sensor networks (WSNs) We assume that the sensor nodes are equipped with ZigBee transceivers for wireless communications. Three well known routing algorithms (AODV, DSR, and OLSR) are simulated in a WSN surveillance scenario. The performances of these routing algorithms are compared in terms of traffic load, delay, packet loss, and energy consumption. Our results indicate that DSR performs better than other algorithms for border surveillance applications. Moreover, a novel algorithm called \"DSR_OP\" is proposed for improving DSR routing in terms energy management in the network and extending the network life time. However Comparisons of WSN routing protocols (DSR, AODV, OLSR and others) are presented since many years ago, but there is no simulation with OPNET, so our novelty is that the validity of proposed method and the comparisons are confirmed by simulations in OPNET.",
"author_names": [
"Hoda Sharei-Amarghan",
"Alireza Keshavarz-Haddad",
"Gaetan Garraux"
],
"corpus_id": 37786246,
"doc_id": "37786246",
"n_citations": 6,
"n_key_citations": 0,
"score": 0,
"title": "Routing Protocols for Border Surveillance Using ZigBee Based Wireless Sensor Networks",
"venue": "CN",
"year": 2013
},
{
"abstract": "Wireless sensor networks have been used in several applications to perform remote monitoring for a certain Area of Interest. In this work, we propose to utilize an Unmanned Aerial Vehicle (UAV) to improve the ground network connectivity, act as a data mule that collects the captured data and off load the ground sensor nodes, who have normally limited storage capacities. We have investigated the effect of several parameters that affect the communication between the UAV and the ground sensors such as the UAV height, communication channel weather conditions, and nodes' noise factor, and evaluated the network performance measured by the average packet loss rate, end to end delay, and throughput. We found out that when the nodes' transceivers have a relatively high noise factor (above 20) it is recommended to keep the UAV altitude around 150 meters or below. We also noticed that the performance degrades drastically when having severe weather conditions, which requires additional mechanisms for improving the transmission performance such as the usage of error correction codes and Multiple Input Multiple Output antennas.",
"author_names": [
"Ala F Khalifeh",
"Mahmoud AlQudah",
"Rabi Tanash",
"Khalid A Darabkh"
],
"corpus_id": 57191071,
"doc_id": "57191071",
"n_citations": 12,
"n_key_citations": 1,
"score": 0,
"title": "A Simulation Study for UAV Aided Wireless Sensor Network Utilizing ZigBee Protocol",
"venue": "2018 14th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob)",
"year": 2018
},
{
"abstract": "1171 Published By: Blue Eyes Intelligence Engineering Sciences Publication Retrieval Number G6350058719/19(c)BEIESP Abstract: Wireless Sensor networks finds its application in various areas such as habitat monitoring, home automation, industrial automation, military applications and health care etc. Even though Wireless sensor networks are omnipresence, they are vulnerable to the various security threats. Sybil attacks are considered to be one of the most important attacks for which the several detection algorithms and systems were designed and implemented. But still the existing algorithms need intelligence for better accuracy of detection. Hence new technique FEM(Fuzzy Extreme machines) is proposed which works on the hybrid Fuzzy and powerful Extreme learning machines for the detection of Sybil attacks. The experiments were conducted on real time Testbeds which consist of ARM as main CPU interfaced with CC2530 Zigbee transceivers and tested in LEACH environment. Results in terms of accuracy detection obtained from the FEM approach proves to be more vital when compared with the other existing classifier algorithms.",
"author_names": [
"V Sujatha",
"E A Mary Anita"
],
"corpus_id": 212442406,
"doc_id": "212442406",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "FEM Hybrid Machine Learning Approach for the Detection of Sybil attacks in the Wireless Sensor Networks",
"venue": "",
"year": 2019
},
{
"abstract": "This chapter introduces concepts and applications relating to wireless data communication. It starts with a review of the principles, including the electromagnetic spectrum, radio transceivers, protocols and antennae. The background to short distance, personal area network protocols is introduced, through reference to IEEE Working Groups. Bluetooth is introduced, and trialled using the RN 41 Bluetooth module. The RN 41 is used to develop key Bluetooth concepts. Simple PC to mbed, and mbed to mbed Bluetooth links are demonstrated. The Zigbee protocol, its typical networks and applications are introduced. XBee radio modules are used to illustrate simple Zigbee links, in Transparent mode. Use of the XBee in its more flexible API mode is then introduced, which opens the door to more advanced Zigbee applications.",
"author_names": [
"Rob Toulson",
"Tim Wilmshurst"
],
"corpus_id": 114638774,
"doc_id": "114638774",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Chapter 11 Wireless Communication Bluetooth and Zigbee",
"venue": "",
"year": 2017
},
{
"abstract": "Wireless sensor networks are important for a variety of today's applications and a high impact in the domains of Internet of Things (IoT) smart grids, smart dust and industrial wireless networks can be expected for the coming years. Even if constantly new created protocols try to achieve common standards, the interoperability remains still a big problem. In this work we propose a new approach, in which we abstract existing protocols in a unified application programming interface (API) realizing a transparent protocol. The proposed API provides the same functions for different platforms and can be easily implemented to operate with several communication solutions. For proof of concept, the transparent protocol is developed, implemented and tested using two heterogeneous transceivers and communication protocols, which are ZigBee and Xbee. Both solutions are accessed using the same program. The data of heterogeneous endpoints is extracted, stored in a common database and visualized in a shared front end.",
"author_names": [
"Martin Gotz",
"Olfa Kanoun"
],
"corpus_id": 52283176,
"doc_id": "52283176",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Transparent Protocol for Interoperability in Wireless Sensor Networks",
"venue": "2018 International Conference on Advances in Big Data, Computing and Data Communication Systems (icABCD)",
"year": 2018
},
{
"abstract": "Display Omitted We measure and model the path loss for wireless links in low voltage substations.No effect of EMI on Zigbee links is normally observed in high voltage substations.The probability of unsuccessful polling transactions Put is analytically studied.Sending multiple copies of data by WiFi 5GHz transmitters achieves near zero Put. Supervisory control and data acquisition (SCADA) systems currently use the polling technique for monitoring electric utility networks. Unfortunately, conventional SCADA systems do not suit the needs of smart grids in terms of the required data rate. Polling based wireless networks can extend the capabilities of SCADA systems as they provide low cost transceivers and bounded packet delay. However, the harsh environment of power stations negatively impacts the performance of wireless links. This paper introduces a field measurement based study that focuses on the effect of power system noise and transients on packet delivery reliability of Zigbee and WiFi polling based wireless networks. Extensive experiments show that the electromagnetic interference emitted from high voltage substations, during normal operation conditions, do not significantly affect wireless communication in the gigahertz range. Moreover, we analytically and experimentally demonstrate that abnormal operation conditions of power systems may negatively impact the reliability of packet delivery in polling based wireless networks. Furthermore, we show that this negative impact can be mitigated by following some proposed technical considerations regarding the wireless standard, the operating frequency, the location, and the number of wireless transceivers used.",
"author_names": [
"Atef Abdrabou",
"Ahmed M Gaouda"
],
"corpus_id": 1629005,
"doc_id": "1629005",
"n_citations": 10,
"n_key_citations": 0,
"score": 0,
"title": "Considerations for packet delivery reliability over polling based wireless networks in smart grids",
"venue": "Comput. Electr. Eng.",
"year": 2015
}
] |
All optical wavelength converters based on cross phase modulation in SOA-MZI configuration | [
{
"abstract": "Abstract Wavelength converter plays an important role for increasing the capacity and flexibility of future broadcast network. The cross phase modulation (XPM) based converter has high conversion efficiency at low input power. In order to improve the efficiency and wideband conversion range, the XPM is increase by optimizing the semiconductor optical amplifiers Mach Zehnder interferometer (SOA MZI) configuration. The XPM is improved by increasing the active region length and bias current of the SOA.",
"author_names": [
"Surinder Singh",
"Rajinder Singh Kaler"
],
"corpus_id": 120192643,
"doc_id": "120192643",
"n_citations": 36,
"n_key_citations": 0,
"score": 1,
"title": "All optical wavelength converters based on cross phase modulation in SOA MZI configuration",
"venue": "",
"year": 2007
},
{
"abstract": "All optical wavelength conversion is demonstrated at 10 Gbit/s over a wavelength span of 10 nm without any bit loss by the use of Semiconductor Optical Amplifier (SOA) in a Mach Zehnder configuration. These wavelength conversion architectures are implemented by using SOA cross gain modulation (XGM) and cross phase modulation (XPM) techniques. We have compared the results of both techniques on the basics of Bit Error Rate (BER) and Quality factor. KeywordsSemiconductor Optical Amplifier (SOA) cross gain modulation (XGM) cross phase modulation (XPM) Mach Zehnder Interferometer, BER, extinction ratio(ER) I.INTRODUCTION All optical wavelength converters are expected to b ecome key components in the future broadband net wo rks. Their most important use will be for avoidance of wavelen gth blocking in optical cross connects in wavelengt h division multiplexed (WDM) networks [1 4] Thereby the converters increase the flexibility and the capacity of the network for a fixed set of wavelengths [5 6] With the help of wavelength conversion a data stream at a specif ic wavelength is transferred to another one in order to be routed on a different wavelength path and release the ori ginal wavelength resource to another data stream. A. Semiconductor optical amplifiers (SOA)An SOA is an optoelectronic device that under suita ble operating conditions can amplify an input light signal. A schematic diagram of a basic SOA is shown in Fig. 1 .1 The active region in the device imparts gain to an input signal. An external electric current provides the e nergy source that enables gain to take place. An em bedded waveguide is used to confine the propagating signal wave to the active region. However, the optical co nfinement is weak so some of the signal will leak into the surro nding lossy cladding regions. The output signal is accompanied by noise. This additive noise is produced by the am plification process itself and so cannot be entirel y avoided. The amplifier facets are reflective causing ripples in the gain spectrum. In an SOA electrons (more common ly referred to as carriers) are injected from an external current source into the active region. The gain of an SOA is influenced both by the input signal power and internal noise generated by the am plification process. As the signal power increases the carriers in the active region become depleted leading to a decrease in the amplifier gain. This gain saturation can cause sign ificant signal distortion. It can also limit the ga in achievable when SOAs are used as multichannel amplifiers. A typical SOA gain versus output signal power characteristic is saturation output power shown in Fig. 1.2. A useful parameter for quantifying gain saturation is the s aturation output power which is defined as the amplifier output signal po wer at which the amplifier gain is half the small s ignal gain. 1275 OPTICAL WAVELENGTH CONVERTERS BASED ON CROSS GAIN MODULATION AND CROSS PHASE MODULATION IN SOA ISSN 2277 1956/V1N3 1274 1280 Figure 1. SOA structure Figure 1.2 Gain Saturation Semiconductor optical amplifiers (SOAs) are used in the cross gain modulation (XGM) mode or the cross phase modulation (XPM) mode for wavelength conversion. II. CROSS GAIN MODULATION BASED WAVELENGTH CONVERSION",
"author_names": [
"M Tech Pursuing",
"Ms Geetanjli Pandove",
"Tarun Kumar Gupta"
],
"corpus_id": 11645208,
"doc_id": "11645208",
"n_citations": 6,
"n_key_citations": 0,
"score": 0,
"title": "OPTICAL WAVELENGTH CONVERTERS BASED ON CROSS GAIN MODULATION AND CROSS PHASE MODULATION IN SOA",
"venue": "",
"year": 2012
},
{
"abstract": "According to the simplified system model, the converted signal chirp of all optical wavelength converter based on cross gain modulation in semiconductor optical amplifier is explored in detail. The influence of the signal power, probe power, signal pulse width and pump current on the chirp is simulated. The chirp dependence on the signal pattern is analyzed.",
"author_names": [
"Feng Jian-he",
"L Zte"
],
"corpus_id": 123795855,
"doc_id": "123795855",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Converted Signal Chirp of All optical wavelength converters Based on Cross gain Modulation in SOA Caused by Phase Modulated",
"venue": "",
"year": 2001
},
{
"abstract": "Abstract The emergence of new services and data exchange applications has increased the demand for bandwidth among individuals and commercial business users at the access area. Thus, vendors of optical access networks should achieve a high capacity system. This study demonstrates the performance of an integrated configuration of one to four multi wavelength conversions at 10 Gb/s based on cross phase modulation using semiconductor optical amplifier integrated with Mach Zehnder interferometer. The Opti System simulation tool is used to simulate and demonstrate one to four wavelength conversions using one modulated wavelength and four probes of continuous wave sources. The wavelength converter processes are confirmed through investigation of the input and output characteristics, optical signal to noise ratio, conversion efficiency, and extinction ratio of new modulated channels after separation by demultiplexing. The outcomes of the proposed system using single channel indicate that the capacity can increase from 10 Gb/s to 50 Gb/s with a maximum number of access points increasing from 64 to 320 (each point with 156.25 Mb/s bandwidth) The splitting ratio of 1:16 provides each client with 625 Mb/s for the total number of 80 users. The Q factor and bit error rate curves are investigated to confirm and validate the modified scheme and prove the system performance of the full topology of 25 km with 1/64 splitter. The outcomes are within the acceptable range to provide the system scalability.",
"author_names": [
"Mohammad Syuhaimi Ab-Rahman",
"Abdulhameed Almabrok Swedan"
],
"corpus_id": 116022457,
"doc_id": "116022457",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Quadruple multi wavelength conversion for access network scalability based on cross phase modulation in an SOA MZI",
"venue": "",
"year": 2017
},
{
"abstract": "In this paper, the all optical up and down wavelength converter based on cross polarization modulation (XPolM) effect in semiconductor optical amplifier Mach Zehnder Interferometer (SOA MZI) has been proposed and evaluated for error free operation to show the feasibility of 40 Gbps differential phase shift keying modulated data signal. The wavelength conversion is achieved by rotational state of polarization of pump and probe signal in SOA. Also, investigation of wavelength converter is theoretically and analytically validated for optimum performance and investigation results show good agreement with each other. The impact of variable signal power along with different parameter of SOA on performance of converted wavelength signal in terms of optical received power and Q factor has been given. The investigations revealed that wavelength converter based on XPolM effect in SOA MZI can be the promising option to enhance the expandability and accessibility of future hybrid optical access networks.",
"author_names": [
"Sukhbir Singh",
"Surinder Singh"
],
"corpus_id": 213921104,
"doc_id": "213921104",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Design of optical wavelength conversion based on cross polarization modulation effect of SOA MZI",
"venue": "",
"year": 2020
},
{
"abstract": "In this paper, a multi wavelength converter based on cross phase modulation (XPM) effect in dual highly nonlinear fibers (HNLFs) for 60 Gbps non return to zero/differential quadrature phase shift keying (NRZ/DQPSK) orthogonally modulated signal has been proposed. In the proposed wavelength converter, orthogonal modulation formats are used to enhance the spectral efficiency of system for physical layer expandability of optical network. The merit of proposed scheme is that the configuration of wavelength converter is simple and easy to implement at higher data rate. The BER performance of all converted signal is greater than or equal to 5.36 x 10 24 and spectral efficiency of designed wavelength converter is 9.75 b/s/Hz which makes the system more cost effective and expandable. In addition, the proposed multi wavelength converter has been validated at variable HNLF parameters to achieve optimum wavelength conversion performance.",
"author_names": [
"Sukhbir Singh",
"Surinder Singh"
],
"corpus_id": 219032899,
"doc_id": "219032899",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "An approach to multi wavelength conversion based on cross phase modulation effect in dual HNLFs for optical orthogonal modulation format",
"venue": "",
"year": 2020
},
{
"abstract": "Abstract The novel designs of all optical logic gates using cross gain modulation and cross phase modulation in semiconductor optical amplifiers, have been suggested and demonstrated successfully at 10 Gb/s. Mach Zehnder configuration with two 3 dB couplers is used to introduce phase modulation on the saturated inverted output of SOA. No additional input beam such as clock signal or continuous light wave is used as in several other designs. In the designs, one data act as a pump and another act as a probe signal. Therefore, while passing through SOA, one data acting as a pump, saturates another data which is a probe signal. Different arrangements of input part of SOA MZI, create three gates such as AND, XOR and OR. Gates are analyzed according to the extinction ratio, wavelength spectrum, frequency chirping and bit error rate. Very high extinction ratio is found i.e. 54.5, 36.32 and 37.5 at 1550.5 nm for AND, XOR and OR gates respectively. The wavelength spectrum, of all the three gates, lies within 1554.8 nm to 1555.2 nm which is near the central wavelength of probe pulse at 1550 nm. Negative frequency chirp are found for all the three gates with bit error rate 7.1x10 30 1x10 31 and 2.1x10 12 for AND, XOR and OR respectively.",
"author_names": [
"Pallavi Singh",
"Devendra Kumar Tripathi",
"Shikha Jaiswal",
"H K Dixit"
],
"corpus_id": 121747975,
"doc_id": "121747975",
"n_citations": 22,
"n_key_citations": 1,
"score": 0,
"title": "Design and analysis of all optical AND, XOR and OR gates based on SOA MZI configuration",
"venue": "",
"year": 2015
},
{
"abstract": "All optical signal up conversion into the millimeter wave frequency band is demonstrated using a semiconductor optical amplifier Mach Zehnder interferometer (SOA MZI) wavelength converter, which is based on a cross phase modulation (XPM) effect in the SOA. This scheme shows good conversion efficiency with polarization immunity and no increase in phase noise. The measured phase noise of the up converted RF signal of 32.5 GHz is 79.2 dBc/Hz at 10 KHz offset, which is limited by that from the LO signal. A two tone measurement is performed to characterize the linearity of the signal up conversion. The measured spurious free dynamic range (SFDR) is 75.2 dB/spl middot/Hz/sup 2/3/ which meets the SFDR requirement for mobile communication systems.",
"author_names": [
""
],
"corpus_id": 21063385,
"doc_id": "21063385",
"n_citations": 31,
"n_key_citations": 1,
"score": 0,
"title": "Signal up conversion by using a cross phase modulation in all optical SOA MZI wavelength converter",
"venue": "IEEE Photonics Technology Letters",
"year": 2004
},
{
"abstract": "All optical signal up conversion into the millimeter wave frequency band is demonstrated using a semiconductor optical amplifier Mach Zehnder interferometer (SOA MZI) wavelength converter, which is based on a cross phase modulation (XPM) effect in the SOA. This scheme shows good conversion efficiency with polarization immunity and no increase in phase noise. The measured phase noise of the up converted RF signal of 32.5 GHz is 79.2 dBc/Hz at 10 KHz offset, which is limited by that from the LO signal. A two tone measurement is performed to characterize the linearity of the signal up conversion. The measured spurious free dynamic range (SFDR) is 75.2 dB/spl middot/Hz/sup 2/3/ which meets the SFDR requirement for mobile communication systems.",
"author_names": [
"Ho-Jin Song",
"Jeong Seon Lee",
"Jong-In Song"
],
"corpus_id": 111066665,
"doc_id": "111066665",
"n_citations": 41,
"n_key_citations": 1,
"score": 0,
"title": "Signal up conversion by using a cross phase modulation in all optical SOA MZI wavelength converter",
"venue": "",
"year": 2004
},
{
"abstract": "This paper proposed and experimentally demonstrated the effective design of a single to dual channel 100 Gbit/s wavelength converter with a simple configuration consisting of a single dispersion flattened highly nonlinear photonic crystal fiber (DS HNL PCF) and two optical bandpass filters (OBPFs) The polarity preserved, ultrafast wavelength conversion with single to dual channel multicasting is achieved by simultaneously filtering the red and blue chirped spectral component of a probe light. Moreover, the wavelength tunability and dynamic characteristics of designed wavelength converter are investigated. The results show that the designed ultrafast wavelength converter has a wide wavelength conversion range of 29 nm, and high tolerance to input power fluctuations. It is very attractive for engineering application in modern microwave and ultrafast photonic networks.",
"author_names": [
"Jiamin Gong",
"Z Q Hui"
],
"corpus_id": 122208886,
"doc_id": "122208886",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Experimental demonstration of all optical 100 Gbit/s wavelength conversion with 1 to 2 wavelength multicasting based on cross phase modulation in dispersion flattened highly nonlinear photonic crystal fiber",
"venue": "",
"year": 2014
}
] |
Recent Advances in Silicon Carbide Device Based Power MOSFETs | [
{
"abstract": "Silicon Carbide (SiC) has revolutionized the semiconductor power devices. It is a wide band gap semiconductor with an energy gap wider than 2eV and possesses extremely high power high voltage switching characteristics, high thermal, chemical and mechanical stability. The SiC wafers are available in 6H, 4H, 2H and 3C polytypes. Because of its wide band gap, the leakage current of SiC is many orders of magnitude lower than in Silicon. Also forward resistance of SiC power devices is approximately 200 times lower than conventional silicon devices. The breakdown voltage of SiC is 8 10 times higher than that of Silicon. In this paper DIMOSFET, UMOSFET and Lateral Power MOSFET are discussed along with their characteristics and applications. Different Crystal structures used for SiC are also highlighted in this paper.",
"author_names": [
"Munish Vashishath"
],
"corpus_id": 220494518,
"doc_id": "220494518",
"n_citations": 0,
"n_key_citations": 0,
"score": 1,
"title": "Recent Advances in Silicon Carbide Device Based Power MOSFETs",
"venue": "",
"year": 2020
},
{
"abstract": "Abstract Thin films of silicon carbide (SiC) have been grown at 1000 1500 degC on vicinal and on axis a(6H) SiC(0001) substrates by gas source molecular beam epitaxy (GSMBE) Growth using only SiH 4 and C 2 H 4 resulted in 3C SiC(111) epilayers under all deposition conditions and substrate orientations. With the addition of H 2 films of 6H SiC(0001) were deposited on the vicinal substrates at deposition temperatures 1350 degC. Kinetic analysis showed all depositions to be surface reaction controlled. In situ doping was achieved by intentional introduction of nitrogen and aluminum into the growing crystals. SiC based microelectronic devices operable at elevated temperatures, including several types of power metal oxide semiconductor field effect transistors (MOSFETs) bipolar transistors, and thyristors have been fabricated. The properties of selected devices and the circuits made from them are described.",
"author_names": [
"R Scott Kern",
"Robert F Davis"
],
"corpus_id": 97515783,
"doc_id": "97515783",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "Silicon carbide for high temperature microelectronics: recent advances in material growth via gas source MBE and device research",
"venue": "",
"year": 1997
},
{
"abstract": "Medium voltage (MV) Silicon Carbide (SiC) power devices have become available as engineering samples. Recent studies show that they outperform their Silicon (Si) counterparts regarding voltage blocking capability, specific on state resistance, switching speed and maximum allowable junction temperature. It is projected that MV SiC power devices will bring revolutionary changes in medium and high voltage applications such as traction drives for locomotives, industrial motor drives, utility power transmission systems, etc. This paper presents a summary of recent advances in MV SiC power devices, including MOSFETs, IGBTs, GTOs and super cascode devices. Technical challenges of their applications such as device packaging, gate drive design and gate drive auxiliary power supply design are discussed. Testing results of three state of the art MV SiC devices, including a 4 kV, 5 A discrete SiC MOSFET, a 4.5 kV, 40 A SiC super cascode device and a 10 kV, 40 A SiC MOSFET power module, are presented as examples.",
"author_names": [
"Boxue Hu",
"Xintong Lyu",
"Diang Xing",
"Dihao Ma",
"John Alex Brothers",
"Risha Na",
"Jin Wang"
],
"corpus_id": 54450373,
"doc_id": "54450373",
"n_citations": 8,
"n_key_citations": 0,
"score": 0,
"title": "A Survey on Recent Advances of Medium Voltage Silicon Carbide Power Devices",
"venue": "2018 IEEE Energy Conversion Congress and Exposition (ECCE)",
"year": 2018
},
{
"abstract": "Emerging silicon carbide (SiC) MOSFET power devices promise to displace silicon IGBTs from the majority of challenging power electronics applications by enabling superior efficiency and power density, as well as capability to operate at higher temperatures. This paper reports on the recent progress in development of 1200V SiC power MOSFETs. Two different chip sizes were fabricated and tested: 15A (0.225cmx0.45cm) and 30A (0.45cmx0.45cm) devices. First, the 30A MOSFETs were packaged as discrete components and static and switching measurements were performed. The device blocking voltage was 1200V and typical on resistance was less than 50 mO with gate source voltages of 0V and 20V, respectively. The total switching losses were 0.6 mJ, over five times lower than the competing devices. Next, a buck converter was built for evaluating long term stability of the MOSFETs and typical switching waveforms are presented. Finally, the 15A MOSFETs were used for fabrication of 150A all SiC modules. The module on resistance values were in the range of 10 mQ, resulting in the best in class on state voltage values of 1.5V at nominal current. The module switching losses were 2.3 mJ during turn on and 1 mJ during turn off, also significantly better than competing designs. The results validate performance advantages of the SiC MOSFETs, moving them a step closer to power electronics applications.",
"author_names": [
"Ljubisa Dragoljub Stevanovic",
"Kevin S Matocha",
"Peter Almern Losee",
"John Stanley Glaser",
"Jeffrey Joseph Nasadoski",
"S D Arthur"
],
"corpus_id": 25107825,
"doc_id": "25107825",
"n_citations": 90,
"n_key_citations": 6,
"score": 0,
"title": "Recent advances in silicon carbide MOSFET power devices",
"venue": "2010 Twenty Fifth Annual IEEE Applied Power Electronics Conference and Exposition (APEC)",
"year": 2010
},
{
"abstract": "In order to avoid the loss caused by sudden power failure or loss, UPS is very necessary.As the core part of UPS, the efficiency of DC DC converter improvement has been a long term research direction in the industry.Switch tube loss are the main factors influencing the DCDC converter efficiency, SI power component is affected by its material, its performance is difficult to further improve, seriously affect the efficiency of the DC DC converter, SiC semiconductor with high band gap width, the advantages of high heat conductivity and high electric breakdown strength in recent years become a hot research direction at home and abroad, and silicon carbide material improves the device the possibility of high frequency, miniaturization and efficiency.Compared with Si power devices, the advantages of SiC power devices are higher voltage and temperature resistance, higher operating frequency and lower switching losses.",
"author_names": [
"Pengfei Zhang",
"Xiu Ying Ren",
"Hong Zhang",
"Dewen Zhang",
"See Lan",
"Siwei Han",
"Meng Wang"
],
"corpus_id": 218686177,
"doc_id": "218686177",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Research on Efficiency Improvement of UPS Based on Silicon Carbide MOSFET",
"venue": "",
"year": 2020
},
{
"abstract": "With the many well known attributes of wide bandgap (WBG) power devices, especially silicon carbide (SiC) and gallium nitride (GaN) FETs, the WBG adoption has been growing constantly for the past few years. Lately, with significant improvements in reliability and commercial availability, several manufacturers have taken SiC and GaN based products to production. Market data from research firms, such as Yole and IHS, show that this trend will continue to rise during the next five to 10 years.",
"author_names": [
"Ashok Bindra"
],
"corpus_id": 202158341,
"doc_id": "202158341",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Recent Advances in Gate Driver Integrated Circuits for Wide Bandgap FETs: Manufacturers introduce gate drivers for squeezing the best performance out of WBG devices",
"venue": "IEEE Power Electronics Magazine",
"year": 2019
},
{
"abstract": "This paper presents recent research on several silicon carbide (SiC) power devices. The devices have been tested for both static and dynamic characteristics, which show the advantages over their Si counterparts. The temperature dependency of these characteristics has also been presented in this paper. Then, simulation work of paralleling operation of SiC power MOSFETs based on a verified device model in Pspice is presented to show the impact of parasitics in the circuit on the switching performance.",
"author_names": [
"Yutian Cui",
"Madhu Sudhan Chinthavali",
"Fan Xu",
"Leon M Tolbert"
],
"corpus_id": 51117,
"doc_id": "51117",
"n_citations": 45,
"n_key_citations": 1,
"score": 0,
"title": "Characterization and modeling of silicon carbide power devices and paralleling operation",
"venue": "2012 IEEE International Symposium on Industrial Electronics",
"year": 2012
},
{
"abstract": "In recent years, silicon carbide (SiC) high power devices have received widespread attention with the development of wide bandgap semiconductor. Using multi scale modelling (finite element and molecular dynamics simulations) a considerable weakness breakdown region was revealed at P base corner near JFET region under overvoltage condition due to electronic field gathered. Besides, a hot pot is observed in JFET region when SiC MOSFET is shorted in circuit. The molecular dynamics simulations suggest that high temperature makes electrode metal melted and gate oxide also becomes unreliable above the hot spot area.",
"author_names": [
"Kai Zheng",
"Hou-Cai Luo",
"Liming Wang",
"Chun-Jian Tan",
"Shao-Gang Wang",
"Huaiyu Ye",
"Xianping Chen"
],
"corpus_id": 44174530,
"doc_id": "44174530",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Multi scale modelling of internal failure mechanism of SiC power MOSFETs",
"venue": "2018 19th International Conference on Thermal, Mechanical and Multi Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)",
"year": 2018
},
{
"abstract": "Abstract Gallium oxide possesses material properties that are advantageous for power electronic devices. Combined with the availability of native Ga2O3 substrates, Ga2O3 based devices are projected to supplant Si based as well as GaN and SiC based power electronics over a certain slice of the high voltage, low frequency application space. The b type of Ga2O3 is clearly the most developed polymorph of Ga2O3. Devices based on b Ga2O3 have not reached below the expected 8 MV/cm theoretical value for breakdown voltage. The best Schottky barrier diodes based on b Ga2O3 have achieved a breakdown strength of only approximately 1 MV/cm. Recent results in Schottky diodes fabricated from 0.43 mm mist grown a Ga2O3 displayed a breakdown strength of 12 MV/cm. For transistors, a 3.8 MV/cm breakdown strength was obtained for a 0.65 mm channel length device. The best reported breakdown voltage of 755 V only corresponds to 0.5 MV/cm breakdown strength that was obtained for a 15 mm channel length device. As material quality improves, it is expected that the experimental breakdown voltages will approach the theoretical predictions. A clear research path is that large area and vertical devices will mirror the designs of silicon and silicon carbide power devices particularly with an emphasis on vertical design with defined conduction paths. The relatively low thermal conductivity of Ga2O3 creates self heating effects that must be mitigated in order to utilize Ga2O3 for high power at even moderate switching frequencies. Lastly, the current state of p type b Ga2O3 is currently an issue to utilized pn junctions to define the current path in vertical devices. This issue, like many aspects of Ga2O3, is rapidly evolving.",
"author_names": [
"Michael A Mastro"
],
"corpus_id": 140046472,
"doc_id": "140046472",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Power MOSFETs and diodes",
"venue": "",
"year": 2019
},
{
"abstract": "Abstract Silicon carbide (SiC) and gallium nitride (GaN) devices are considered as optimal solutions to meet the requirements of the modern power electronics. In fact, they can allow an improved efficiency in energy conversion at high power, as required today in several strategic application fields (like consumer electronics, renewable energies technology, transportation, electric power distribution, etc. However, while in the last decades impressive progresses have been recorded both in SiC and GaN devices, the full exploitation of these materials has not been reached yet, due to some open technological key issues. This paper reviews some recent advances in dielectrics technology currently adopted to optimize the performances of SiC and GaN transistors. In particular, in the case of SiC the discussion is focused on the optimization of SiO2/SiC interfaces in 4H SiC MOSFETs technology by passivation processes of the gate oxides. On the other hand, the current trends in dielectrics passivation for GaN based HEMTs to limit the gate leakage and the current collapse are discussed.",
"author_names": [
"Fabrizio Roccaforte",
"Patrick Fiorenza",
"Giuseppe Greco",
"Marilena Vivona",
"R Lo Nigro",
"Filippo Giannazzo",
"Alfonso Patti",
"M Saggio"
],
"corpus_id": 110771683,
"doc_id": "110771683",
"n_citations": 99,
"n_key_citations": 3,
"score": 0,
"title": "Recent advances on dielectrics technology for SiC and GaN power devices",
"venue": "",
"year": 2014
}
] |
impact ionization coefficient diamond | [
{
"abstract": "Although a high breakdown voltage or field is considered as a major advantage of diamond, there has been a large difference in breakdown voltages or fields of diamond devices in literature. Most of these apparently contradictory results did not correctly reflect material properties because of specific device designs, such as punch through structure and insufficient edge termination. Once these data were removed, the remaining few results, including a record high breakdown field of 20 MV/cm, were theoretically reproduced, exactly calculating ionization integrals based on the ionization coefficients that were obtained after compensating for possible errors involved in reported theoretical values. In this compensation, we newly developed a method for extracting an ionization coefficient from an arbitrary relationship between breakdown voltage and doping density in the Chynoweth's framework. The breakdown field of diamond was estimated to depend on the doping density more than other materials, and accordingly required to be compared at the same doping density. The figure of merit (FOM) of diamond devices, obtained using these breakdown data, was comparable to the FOMs of 4H SiC and Wurtzite GaN devices at room temperature, but was projected to be larger than the latter by more than one order of magnitude at higher temperatures about 300 degC. Considering the relatively undeveloped state of diamond technology, there is room for further enhancement of the diamond FOM, improving breakdown voltage and mobility. Through these investigations, junction breakdown was found to be initiated by electrons or holes in a p type or n type drift layer, respectively. The breakdown voltages in the two types of drift layers differed from each other in a strict sense but were practically the same. Hence, we do not need to care about the conduction type of drift layers, but should rather exactly calculate the ionization integral without approximating ionization coefficients by a power function of electric field as often done in Si devices. In order to facilitate this approach, we developed a method for simplifying the ionization integral, which method, together with the aforementioned method for extracting ionization coefficients, will help to promote the study on breakdown phenomena of all semiconductors.",
"author_names": [
"Atsushi Hiraiwa",
"Hiroshi Kawarada"
],
"corpus_id": 122338796,
"doc_id": "122338796",
"n_citations": 42,
"n_key_citations": 3,
"score": 0,
"title": "Figure of merit of diamond power devices based on accurately estimated impact ionization processes",
"venue": "",
"year": 2013
},
{
"abstract": "A general formalism has been developed for the calculation of band band Auger recombination and impact ionization rates in diamond and zinc blende type structures. The energy gap involved in the transition must be of order 1eV or greater, at room temperature, for direct gaps but is arbitrary for indirect gaps. A recombination coefficient of 28.1 x 10 32 cm6s 1 for GaP (hole hole electron collision) has been obtained in reasonable agreement with experiment. The formalism gives better theoretical values for Ge and Si than so far available. This has tended to reduce the recombination rates expected theoretically.",
"author_names": [
"Dorothy Hill",
"Peter Landsberg"
],
"corpus_id": 97269525,
"doc_id": "97269525",
"n_citations": 35,
"n_key_citations": 0,
"score": 0,
"title": "A formalism for the indirect Auger effect. I",
"venue": "Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences",
"year": 1976
},
{
"abstract": "The avalanche photodiode is a highly sensitive photon detector with wide applications in optical communication and single photon detection. ZnO is a promising wide band gap material to realize a UV avalanche photodiode (APD) However, the lack of p type doping, the strong self compensation effect, and the scarcity of data on the ionization coefficients restrain the development and application of ZnO APD. Furthermore, ZnO APD has been seldom reported before. In this work, we employed a p Si/i ZnO/n AZO structure to successfully realize electron avalanche multiplication. Based on this structure, we investigated the band structure, field profile, Current Voltage (I V) characteristics, and avalanche gain. To examine the influence of the width of the i ZnO layer on the performance, we changed the i ZnO layer thickness to 250, 500, and 750 nm. The measured breakdown voltages agree well with the corresponding threshold electric field strengths that we calculated. The agreement between the experimental data and calculated results supports our analysis. Finally, we provide data on the impact ionization coefficients of electrons for ZnO along the (001) direction, which is of great significance in designing high performance low excess noise ZnO APD. Our work lays a foundation to realize a high performance ZnO based avalanche device.",
"author_names": [
"Gaoming Li",
"Xiaolong Zhao",
"Xiangwei Jia",
"Shuangqing Li",
"Yongning He"
],
"corpus_id": 220976414,
"doc_id": "220976414",
"n_citations": 1,
"n_key_citations": 0,
"score": 1,
"title": "Characterization of Impact Ionization Coefficient of ZnO Based on a p Si/i ZnO/n AZO Avalanche Photodiode",
"venue": "Micromachines",
"year": 2020
},
{
"abstract": "A valanche multiplication characteristics in GaN p n junction diodes (PNDs) under high reverse bias conditions were investigated. The GaN on GaN PNDs with double side depleted shallow bevel termination, which showed low reverse leakage current and excellent avalanche capability, were used for the measurements. Under sub bandgap light illumination, the photocurrents induced by Franz Keldysh (FK) effect, which can be well reproduced by the theoretical calculations of the optical absorption, and their avalanche multiplications were observed. The multiplication factors were extracted as the ratios of the experimental photocurrents to the calculated FK induced photocurrent. Under an assumption of equal impact ionization coefficients of electrons and holes, the electric field dependence of an impact ionization coefficient in GaN were estimated.",
"author_names": [
"Takuya Maeda",
"Tetsuo Narita",
"Hiroyuki Ueda",
"Masakazu Kanechika",
"Tsutomu Uesugi",
"Tetsu Kachi",
"Tsunenobu Kimoto",
"Masahiro Horita",
"Jun Suda"
],
"corpus_id": 195884249,
"doc_id": "195884249",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Estimation of Impact Ionization Coefficient in GaN by Photomulitiplication Measurement Utilizing Franz Keldysh Effect",
"venue": "2019 31st International Symposium on Power Semiconductor Devices and ICs (ISPSD)",
"year": 2019
},
{
"abstract": "This abstract presents an experimental study on the measurement of the hole impact ionization coefficient and saturation velocity in GaN. A novel p n structure with a buried p GaN was designed and demonstrated to have avalanche capability. Ultraviolet generated holes were swept into the high electric field region when the p n diode was reversely biased and triggered the hole initiated impact ionization multiplication. The measured hole saturation velocity is $7\\times 10^{6} cm/s, and the impact ionization coefficient is \\boldsymbol{\\beta}\\boldsymbol{E}=4.39\\times 10^{6}\\mathbf{exp} 1.8\\times 10^{7}\\boldsymbol{E}",
"author_names": [
"Dong Ji",
"Burcu Ercan",
"Srabanti Chowdhury"
],
"corpus_id": 201810388,
"doc_id": "201810388",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Experimental Determination of Hole Impact Ionization Coefficient and Saturation Velocity in GaN",
"venue": "2019 Compound Semiconductor Week (CSW)",
"year": 2019
},
{
"abstract": "We report on the observation of ultrafast impact ionization in monocrystalline diamond driven by high intensity mid infrared femtosecond laser pulses. The measurements are based on monitoring the excited carrier population during and after the interaction of the pre excited sample with a strong infrared pulse by transient transmission spectroscopy and photoluminescence measurements. A twofold increase in the initial carrier population due to impact ionization is observed with the peak infrared intensity of 2.5 TW/cm2. The experimental results are supported by numerical simulations of electron dynamics using time dependent density functional theory, which show that the electrons in the conduction band reach the energy threshold for impact ionization during the interaction with the infrared pulse.",
"author_names": [
"Martin Kozak",
"Michal Martinek",
"Tomohito Otobe",
"Frantisek Trojanek",
"Petr Maly"
],
"corpus_id": 225634833,
"doc_id": "225634833",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Observation of ultrafast impact ionization in diamond driven by mid infrared femtosecond pulses",
"venue": "",
"year": 2020
},
{
"abstract": "This work exhibits a modified procedure to compute the electron impact ionization coefficient of silicon for temperatures between 77 and 800K and electric fields ranging from 70 to 400 kV/cm. The ionization coefficients are computed from the electron momentum distribution function through solving the Boltzmann transport equation (BTE) The arrangement is acquired by joining Legendre polynomial extension with BTE. The resulting BTE is solved by differences differential method using MATLAB(r) Six (X) equivalent ellipsoidal and non parabolic valleys of the conduction band of silicon are taken into account. Concerning the scattering mechanisms, the interval acoustic scattering, non polar optical scattering and II scattering are taken into consideration. This investigation showed that the ionization coefficients decrease with increasing temperature. The overall results are in good agreement with previous experimental and theoretical reported data predominantly at high electric fields.",
"author_names": [
"M J Ahmed"
],
"corpus_id": 102741312,
"doc_id": "102741312",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Temperature dependence of electron impact ionization coefficient in bulk silicon",
"venue": "",
"year": 2017
},
{
"abstract": "97% des articles publies sur les etudes climatiques racontent que le rechauffement climatique est entierement cause par les activites humaines. Les gaz emis lors de la production d'energie electrique ainsi que d'autres gaz rejetes par les voitures ont un reel impact sur l'atmosphere. Une solution consiste a mettre au point des composants presentant des pertes de conduction plus faibles et des caracteristiques de claquage plus elevees qui pourraient etre utilises dans des centrales nucleaires, des cellules de commutation a haute puissance, des voitures hybrides (electriques) etc.De nos jours, les composants a base de silicium controlent environ 95% des dispositifs electroniques. Le carbure de silicium SiC et le nitrure de gallium GaN sont actuellement a l'etape de R&D, et commencent a etre integres dans certains circuits electroniques. D'autres materiaux tels que Ga2O3, AlN ou le diamant sont encore a l'etape de recherche. Les derniers sont connus sous le nom de materiaux a bande ultra large et semblent etre la solution requise pour les faibles pertes de puissance. Le diamant est reconnu comme le materiau ultime pour la prochaine generation de composants de puissance en raison de ses proprietes physiques exceptionnelles telles qu'un champ de claquage eleve >10 MV/cm) permettant d'utiliser le dispositif pour une commande de puissance elevee, une mobilite de porteurs elevee (2 000 cm^2/V.s pour les trous) une vitesse de saturation elevee, une conductivite thermique elevee (22 W/cm.K) pour une parfaite dissipation de chaleur et une faible constante dielectrique. Theoriquement, le diamant est le semi conducteur offrant le meilleur compromis entre resistance a l'etat passant et tension de claquage. En particulier, en raison de l'ionisation incomplete des dopants, il est encore plus efficace a haute temperature. Diverses diodes Schottky en diamant (SBD) avec de bonnes performances a l'etat passant et bloque (7,7 MV/cm) ont ete rapportees. En plus des SBDs, des transistors a effet de champ (FET) ont egalement ete etudies a travers des oxyde metal semi conducteur FETs (MOSFETs) utilisant une surface hydrogenee avec des densites de courant elevees a l'etat passant ou des surface oxygene avec de bonnes caracteristiques de blocage. Pour les composants de haute tension, il est necessaire de changer l'architecture de l'electrode afin d'eviter un claquage premature due a l'encombrement du champ electrique aux bords. Dans ce but, les techniques de terminaison de bord sont utilisees pour atteindre les caracteristiques ideales. La tache evidente avant toute fabrication de composant est la partie simulation qui predit l'optimisation de l'architecture et les caracteristiques attendues. Une bonne prediction necessite la connaissance des parametres du materiau. Les parametres importants pour le claquage sont les coefficients d'ionisation par impact. Plusieurs coefficients ont ete publies pour le diamant. Toutefois, ils ont ete extraits en fittant des structures non optimisees, d'ou un manque de precision.Dans cette etude, deux structures de terminaisons de bord pour des diodes Schottky, appelees plaque de champ et anneaux a champ flottant, ont ete etudiees. Leur efficacite de distribution du champ de surface par analyse de courant induit par faisceau d'electrons (EBIC) a ete observee. De plus, des FETs ont ete fabriques et caracterises, un MESFET et un RB MESFET. Les FETs presentent un claquage eleve, jusqu'a 3 kV et une faible resistance. Le developpement des transistors est indissociable de la diode Schottky, car ils sont tous deux necessaires a la fabrication de cellules de commutation. Et enfin, les coefficients d'ionisation par impact pour les electrons ont ete mesures a l'aide d'EBIC pour un champ >0,5 MV/cm dans une region sans defaut. Les valeurs mesurees sont (sous l'equation de Chynoweth) an 971 /cm et bn=2,39x10^6 V/cm. Ces valeurs sont proches des coefficients mesures experimentalement et rapportes dans la litterature.",
"author_names": [
"Khaled Driche"
],
"corpus_id": 198452745,
"doc_id": "198452745",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Diamond unipolar devices towards impact ionization coefficients extraction",
"venue": "",
"year": 2018
},
{
"abstract": "Diamond has the advantage of having an exceptionally high critical electric field owing to its large band gap, which implies its high ability to withstand high voltages. At this maximum electric field, the operation of Schottky barrier diodes (SBDs) as well as FETs, may be limited by impact ionization, leading to avalanche multiplication, and hence the devices may breakdown. In this study, three of the reported impact ionization coefficients for electrons, an, and holes, ap, in diamond at room temperature (300 K) are analyzed. Experimental data on reverse operation characteristics obtained from two different diamond SBDs are compared with those obtained from their corresponding simulated structures. Owing to the crucial role played by the impact ionization rate in determining the carrier transport, the three reported avalanche parameters implemented affect the behavior not only of the breakdown voltage but also of the leakage current for the same structure.",
"author_names": [
"Khaled Driche",
"H Umezawa",
"Nicolas Rouger",
"Gauthier Chicot",
"Etienne Gheeraert"
],
"corpus_id": 125722780,
"doc_id": "125722780",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Characterization of breakdown behavior of diamond Schottky barrier diodes using impact ionization coefficients",
"venue": "",
"year": 2017
},
{
"abstract": "Electron impact ionization coefficient a is one of the most important parameters used in the study of gas discharge.However,the a values usually determined in the experiments on Townsend discharge in gases at low pressure are not applicable to the gas discharges in atmospheric gases.Aiming at solving this problem,a method for determining the a values in the gases at atmospheric pressure was proposed.Dielectric barrier Townsend discharges were produced in some gases at atmospheric pressure.The distribution of the light intensity in the discharge gap was recorded by taking side view photograph using an ICCD camera with an extremely short exposure time and compared with the theoretical distributions with different presumed a.The a value was determined by the best fitting of the theoretical distribution to the experimental one.The method was proved to be applicable in the determination of a for nitrogen at atmospheric pressure.",
"author_names": [
"Wang Xinxin"
],
"corpus_id": 98875362,
"doc_id": "98875362",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Preliminary Measurement of Electron Impact Ionization Coefficient in Gases at Atmospheric Pressure",
"venue": "",
"year": 2012
}
] |
Surface emitting semiconductor lasers | [
{
"abstract": "A description is given of the research progress in developing a vertical cavity surface emitting (SE) injection laser based on GaAlAs/GaAs and GaInAsP/InP systems. Ultimate laser characteristics, device design, state of the art performances, possible device improvement, and future prospects will also be discussed. The authors propose a vertical cavity surface emitting semiconductor laser. To reduce the threshold current, they improved the laser reflector and introduced a circular buried heterostructure. The microcavity structure, which is 7 mu m long and 6 mu m in diameter, was realized with a threshold of 6 mA. Thus, possibilities of an extremely low threshold current SE laser device and a densely packed two dimensional array are suggested.",
"author_names": [
"Kenichi Iga",
"Fumio Koyama",
"Susumu Kinoshita"
],
"corpus_id": 120439949,
"doc_id": "120439949",
"n_citations": 585,
"n_key_citations": 11,
"score": 1,
"title": "Surface emitting semiconductor lasers",
"venue": "",
"year": 1988
},
{
"abstract": "",
"author_names": [
"Fumio Koyama",
"Satoshi Shinada",
"Kenya Goto",
"Kenichi Iga"
],
"corpus_id": 136379014,
"doc_id": "136379014",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Surface emitting semiconductor lasers for high capacity optical data storage",
"venue": "",
"year": 1998
},
{
"abstract": "We review the wavelength engineering of micromachined vertical cavity surface emitting lasers (VCSELs) including the wavelength athermalization, wavelength tuning, and multiple wavelength integration. The integration of a thermally actuated cantilever enables us to tailor the temperature dependence of lasing wavelengths. The thermal drift of lasing wavelengths in conventional single mode semiconductor lasers, which is typically 0.07 nm/K, can be compensated by using the thermal actuation of a cantilever mirror. We are able to realize \"athermal operation\" of VCSELs under uncooled operations. This novel function could be useful for WDM optical interconnects, local area networks, and access networks with narrow channel spacing under uncooled operations. In addition, continuous wavelength tuning can be realized by using either electrothermal or electrostatic force actuation of the cantilever structure, which provides the athermal and tunable operation at the same time. Also, the lithography defined multiwavelength integration of an athermal VCSEL array is addressed.",
"author_names": [
"Fumio Koyama",
"Masanori Nakahama"
],
"corpus_id": 46098678,
"doc_id": "46098678",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Micromachined Vertical Cavity Surface Emitting Lasers Athermalization, Tuning, and Multiwavelength Integration",
"venue": "IEEE Journal of Selected Topics in Quantum Electronics",
"year": 2015
},
{
"abstract": "In this paper we review the research progress of surface emitting lasers. A two dimensional arrayed configuration of surface emitting lasers will open up a new era of the semiconductor laser, since it provides high power capability, parallel optical processing, and vertical optical interconnection of circuit boards. We present experimental results on vertical cavity surface emitting semiconductor lasers. In order to reduce the threshold current, some improvements have been made on the laser reflector and a circular buried heterostructure has been introduced to confine injection current more effectively. The microcavity structure, which is 7 mm long and 6 mm in diameter, yields a threshold of 6 mA. A possibility of realizing an extremely low threshold current surface emitting laser device and a densely packed two dimensional array are suggested.",
"author_names": [
"Kenichi Iga",
"Fumio Koyama",
"Susumu Kinoshita"
],
"corpus_id": 97238761,
"doc_id": "97238761",
"n_citations": 10,
"n_key_citations": 0,
"score": 0,
"title": "Surface emitting semiconductor laser array: Its advantage and future",
"venue": "",
"year": 1989
},
{
"abstract": "We propose a micromachined vertical cavity resonator enabling temperature insensitive operation for surface emitting lasers or optical add/drop filters. The strain induced displacement from differential thermal expansion is used to compensate the wavelength shift caused by temperature variation. Also, a wavelength trimming technology using the same principle with precise strain control is suggested. The possibility of a drastic reduction in the temperature sensitivity of wavelengths, as well as precise wavelength adjustment, is presented. We fabricated a micromachined vertical cavity filter with a GaAlAs/GaAs multilayer reflector, which is mechanically tuned by differential thermal expansion. We observed a large negative temperature coefficient of the resonant wavelength. It is demonstrated that its temperature dependence can be widely controlled by the proposed concept. The possibility of temperature insensitive operation is discussed.",
"author_names": [
"Fumio Koyama",
"Takeru Amano",
"N Furukawa",
"Nobuhiko Nishiyama",
"Masakazu Arai",
"Kenichi Iga"
],
"corpus_id": 120615235,
"doc_id": "120615235",
"n_citations": 8,
"n_key_citations": 1,
"score": 0,
"title": "Micromachined Semiconductor Vertical Cavity for Temperature Insensitive Surface Emitting Lasers and Optical Filters",
"venue": "",
"year": 2000
},
{
"abstract": "We have numerically analyzed some thermal characteristics of cw long wavelength surface emitting lasers with epitaxially grown semiconductor distributed Bragg reflectors (DBRs) It was shown that the device thermal resistance for GaAs/AlAs DBRs epitaxially fused to GalnAsP/InP emitting layers is 1/3 of that for GalnAsP/InP DBRs and almost comparable to that for the optimum dielectric cavity. The threshold current lower than 10 mA and the electrical resistance lower than 100 O are necessary to obtain the cw operation beyond room temperature",
"author_names": [
"Toshihiko Baba",
"Tomonobu Kondoh",
"Fumio Koyama",
"Kenichi Iga"
],
"corpus_id": 120899451,
"doc_id": "120899451",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Finite Element Analysis of Thermal Characteristics in Continuous Wave Long Wavelength Surface Emitting Lasers (II) Semiconductor Distributed Bragg Reflectors",
"venue": "",
"year": 1995
},
{
"abstract": "We propose a polarization controlled vertical cavity surface emitting laser (VCSEL) using a birefringent metal/semiconductor polarizer on a distributed Bragg reflector. Theoretically, we found that the proposed concept can provide an extremely large polarization selectivity at the resonant cavity wavelength by adjusting the phase condition between two polarization states. Experimentally, we have demonstrated a 0.98 /spl mu/m InGaAs/GaAs VCSEL with an Au/GaAs polarizer exhibiting a fairly good polarization control and maintaining low thresholds.",
"author_names": [
"Toshikazu Mukaihara",
"N Ohnoki",
"Yusuke Hayashi",
"Fumio Koyama",
"Kenichi Iga"
],
"corpus_id": 122728406,
"doc_id": "122728406",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Polarization control of vertical cavity surface emitting lasers by a birefringent metal/semiconductor polarizer terminating a distributed Bragg reflector",
"venue": "Proceedings of IEEE 14th International Semiconductor Laser Conference",
"year": 1994
},
{
"abstract": "Abstract A microcavity surface emitting (SE) laser is very attractive for future optoelectronic applications such as optical parallel processing and optical interconnections. In order to realize such a low threshold SE laser, micro fabrication providing a low damage etch is one of important issues. We have introduced a reactive ion etch (RIE) and reactive ion beam etch (RIBE) technique to fabricate a tiny dielectric multilayer reflector and micro resonator for surface emitting lasers. In most of SE laser structures, a SiO2/TiO2 dielectric multilayer reflector or semiconductor multilayer mirror is used as high reflective mirrors. However, it has been difficult to fabricate the microcavity with steep side walls by wet chemical etching since each material has different etching rates. Dry etch techniques for multilayer structures, especially for GaInAsP/InP semiconductors, have not been fully studied.",
"author_names": [
"Akihiro Matsutani",
"Fumio Koyama",
"Kenichi Iga"
],
"corpus_id": 136633046,
"doc_id": "136633046",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Micro dry etching process for vertical cavity surface emitting lasers",
"venue": "",
"year": 2008
},
{
"abstract": "The surface emitting laser is one of the leading candidates for a light source supporting next generation ultrahigh speed optical linking techniques. However, in surface emitting lasers, especially for the single mode elements, the challenges include increasing the single mode output and stabilizing the polarization direction, and thus the technique for controlling the polarization and transverse modes is important. In this study, we propose a surface emitting laser with a metal nanoscale aperture array whose permeability shows a strong polarization dependence, formed on a p type semiconductor multilayered film reflector, as a new method for controlling the polarization and transverse modes, and in addition, we explain the potential of its polarization and transverse mode control. (c) 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(3) 49 56, 2007; Published online in Wiley InterScience (www.interscience.wiley. com) DOI 10.1002/ecjb.20261",
"author_names": [
"Jiro Hashizume",
"Fumio Koyama"
],
"corpus_id": 62647673,
"doc_id": "62647673",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Polarization and transverse mode control of vertical cavity surface emitting lasers with metal nano structure",
"venue": "",
"year": 2007
},
{
"abstract": "We present the modeling and the experimental result of a micro machined vertical cavity surface emitting laser with a thermally actuated semiconductor/SiO2 cantilever structure. The modeling result shows a giant wavelength temperature dependence of over 3.5 nm/K. The fabricated device exhibits a temperature dependence of 0.79 nm/K, which is 10 times larger than that of conventional vertical cavity surface emitting lasers (VCSELs)",
"author_names": [
"Masanori Nakahama",
"Hayato Sano",
"Norihiko Nakata",
"Akihiro Matsutani",
"Fumio Koyama"
],
"corpus_id": 122271940,
"doc_id": "122271940",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Giant Wavelength Temperature Dependence of a Micro Machined Vertical Cavity Surface Emitting Laser with a Thermally Actuated Cantilever Structure",
"venue": "",
"year": 2012
}
] |
Recent 10 years of pervoskite materials | [
{
"abstract": "In recent years, Moore's law had a remarkable effect on predicting the development of semiconductor technology. As the size of devices shrinks to micro scale or nano scale, Intel's newest 10 nm logic technology is scheduled to start product shipments before the end of 2017. Moore's law will not die out, as the research scale reaches the atomic scale, \"new devices\" and new interconnection methods are urgently needed. In this paper, based on emerging interconnection requirement, the contribution to the advanced electronic packaging containing novel nano materials, such as the carbon nanotubes, nanoparticles sintering, interconnection of nano solder, nano silver and surface plasma nano welding are discussed. For the next 5 10 years, two new types of interconnect solutions are gaining attentions: solder joint alternatives and Cu electrode alternatives. The former uses new materials such as graphene, carbon nanotubes and nanowires to replace traditional solder joints. The latter uses optical media to replace the traditional Cu metal. In general, advanced materials will make more and more outstanding contributions in the development of electronic packaging in the next 10 20 years.",
"author_names": [
"Shuye Zhang",
"Xiangyu Xu",
"Tiesong Lin",
"Peng He"
],
"corpus_id": 199183771,
"doc_id": "199183771",
"n_citations": 41,
"n_key_citations": 0,
"score": 0,
"title": "Recent advances in nano materials for packaging of electronic devices",
"venue": "Journal of Materials Science: Materials in Electronics",
"year": 2019
},
{
"abstract": "STATEMENT OF PROBLEM The survival and success of tooth supported fixed dental prostheses (FDPs) in long term studies vary greatly, depending on the patient and the size of the FDP. Influencing factors for FDP survival or success may include advanced patient age at the time of FDP treatment, treatment severity, and use of new and cheaper FDP materials. As the patient population ages, prosthodontists will treat tooth wear in a greater number of older adults; however, recent long term studies on such treatments are lacking. PURPOSE The purpose of this retrospective clinical study was to examine extensive, tooth supported FDPs made at 2 specialist clinics in Sweden after 10 years and to compare the outcomes with those of previous studies. MATERIAL AND METHODS Patients rehabilitated by using FDPs of at least 5 units at 2 specialist clinics in Sweden between 2002 and 2006 were recalled after 10 years. Clinical examinations were supplemented by reviewing clinical records and existing radiographs. Statistical analysis was performed by using the Student t test, chi squared test, Fisher exact test, and Kruskal Wallis test (a=.05) RESULTS A total of 152 patients were recalled for clinical examination. Of these, 78 patients attended and were examined. The mean age of the examined group was 70 years (range 36 94) lower than that of those not attending (80 years; range 46 100; P<.05) The mean number of units of the 78 examined FDPs was 7.3 (range 5 12) and 8.0 (range 5 14) for those not examined. FDP configurations in terms of number of units, abutments, pontics, and post and cores did not differ significantly between the 2 groups (P>.05) The survival proportion of the examined 78 FDPs (all units of the original FPD) was 74.4% The success proportion (FDPs without complications) was 52.6% The most frequent complications were caries (14.1% endodontic complications (11.5% loose retainers (7.7% root fractures (5.1% and framework fractures (3.8% FDPs with post and cores (P<.05) and cantilevers (P=.054) especially when in combination (P<.05) showed more complications than FDPs without. Chipping fractures in porcelain were found in 38% of the FDPs (7.7% of the units) with more porcelain fractures on Co Cr frameworks than on gold and titanium alloy frameworks (P<.05) CONCLUSIONS This long term retrospective study indicated that the prognosis for complicated and extensive FDPs in aging patients does not worsen with increased clinical complexity. New materials, treatment complexity, and older patients did not seem to markedly influence prognosis.",
"author_names": [
"Helena Alsterstal-Englund",
"L E Moberg",
"Jenny Petersson",
"J I Smedberg"
],
"corpus_id": 211121955,
"doc_id": "211121955",
"n_citations": 3,
"n_key_citations": 1,
"score": 1,
"title": "A retrospective clinical evaluation of extensive tooth supported fixed dental prostheses after 10 years.",
"venue": "The Journal of prosthetic dentistry",
"year": 2020
},
{
"abstract": "Background Migraine is defined as a recurrent headache of moderate to severe intensity that seriously affects the quality of life. Recent clinical trials have confirmed that acupuncture is effective in treating migraine. We aimed to review the effectiveness of acupuncture in the treatment of migraine by comparing treatment and various control groups in accordance with the newly published guidelines for systematic reviews. Materials and Methods The following databases were searched for relevant articles published from January 1, 2010 to December 31, 2019: Embase, PubMed, Medline, Cochrane Library, and four Chinese databases. The present review included randomized controlled trials in which acupuncture was the sole treatment or an adjunctive treatment for migraine. Two researchers independently conducted the study selection, data extraction, and quality assessment processes. Disagreements between reviewers were solved by discussion and data reanalysis. The quality of each included study was evaluated using the Cochrane Collaboration risk of bias assessment method and the Standards for Reporting Interventions in Controlled Trials of Acupuncture (STRICTA) checklist. Results Forty nine studies were analyzed and ranked based on the latest STRICTA and Cochrane Collaboration risk of bias assessment standards. The analysis revealed that acupuncture reduced headache frequency compared with no treatment (mean difference [MD] 1.80, P 0.00001, 95% confidence interval [CI] 2.34 to 1.26) and western medicine (MD 1.75, P 0.003, 95% CI 2.91 to 0.58) Headache frequency did not significantly differ between patients who received real acupuncture versus those who received sham acupuncture (MD 0.64, P 0.24, 95% CI 1.70 to 0.42) Conclusion The present review evaluated the current research on the use of acupuncture for migraine, compared with various control treatments. The evidence for the effectiveness of acupuncture in controlling migraine is still limited due to the low quality of the published studies.",
"author_names": [
"Xixiu Ni",
"Linglin Dong",
"Tian Tian",
"Lu Liu",
"Xiao Li",
"Fengmei Li",
"Ling Zhao"
],
"corpus_id": 221459186,
"doc_id": "221459186",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Acupuncture versus Various Control Treatments in the Treatment of Migraine: A Review of Randomized Controlled Trials from the Past 10 Years",
"venue": "Journal of pain research",
"year": 2020
},
{
"abstract": "Background: Guided growth through temporary hemiepiphysiodesis has gained acceptance as the preferred primary treatment in treating pediatric lower limb deformities as it is minimally invasive with a lesser morbidity than the traditional osteotomy. The tension band plate is the most recent development in implants used for temporary hemiepiphysiodesis. Our aim was to determine its safety and efficacy in correcting coronal plane deformities around the knee in children younger than 10 years. Materials and Methods: A total of 24 children under the age of 10 were operated for coronal plane deformities around the knee with a single extra periosteal tension band plate and two nonlocking screws. All the children had a pathological deformity for which a detailed preoperative work up was carried out to ascertain the cause of the deformity and rule out physiological ones. The average age at hemiepiphysiodesis was 5 years 3 months (range: 2 years to 9 years 1 month) Results: The plates were inserted for an average of 15.625 months (range: 7 months to 29 months) All the patients showed improvement in the mechanical axis. Two patients showed partial correction. Two cases of screw loosening were observed. In the genu valgum group, the tibiofemoral angle improved from a preoperative mean of 19.89deg valgus (range: 10deg valgus to 40deg valgus) to 5.72deg valgus (range: 2deg varus to 10deg valgus) In patients with genu varum the tibiofemoral angle improved from a mean of 28.27deg varus (range: 13deg varus to 41deg varus) to 1.59deg valgus (range: 0 8deg valgus) Conclusion: Temporary hemiepiphysiodesis through the application of the tension band plate is an effective method to correct coronal plane deformities around the knee with minimal complications. Its ease and accuracy of insertion has extended the indication of temporary hemiepiphysiodesis to patients younger than 10 years and across a wide variety of diagnosis including pathological physis, which were traditionally out of the purview of guided growth.",
"author_names": [
"Ruta M Kulkarni",
"Faizaan M Ilyas Rushnaiwala",
"Gs Kulkarni",
"Rajiv Negandhi",
"Milind Govind Kulkarni",
"Sunil Govind Kulkarni"
],
"corpus_id": 19755717,
"doc_id": "19755717",
"n_citations": 22,
"n_key_citations": 2,
"score": 0,
"title": "Correction of coronal plane deformities around the knee using a tension band plate in children younger than 10 years",
"venue": "Indian journal of orthopaedics",
"year": 2015
},
{
"abstract": "Purpose This study was conducted to analyze the clinical characteristics and treatments of patients with genitourinary tuberculosis (GUTB) over the past 10 years. Materials and Methods The study population comprised 101 patients who were diagnosed with GUTB and hospitalized from January 2000 to December 2009. Acid fast bacilli (AFB) smear, urine tuberculosis culture, urine tuberculosis polymerase chain reaction (PCR) intravenous urography, cystoscopy, and histopathologic findings were used for patient selection. Yearly proportion, gender, patient distribution according to age, history of tuberculosis, and presence of other organ tuberculosis were analyzed. Results The patients hospitalized with GUTB counted for 0.9% of all patients admitted to the department of urology. The sex ratio was 1:1.53 (male:female) and the patients' mean age was 45.57+ 12.55 years (range, 19 81 years) Among the patients, there was one immunocompromised patient. A total of 22 patients (21.8% had a medical history of tuberculosis, mostly pulmonary tuberculosis (90.9% The sensitivity of AFB stain, tuberculosis culture, and PCR was 41.6% 55.4% 33.7% respectively. A total of 54 patients required additional surgical treatment: 30 cases of nephrectomy, 8 cases of epididymectomy, 8 cases of ureteral stent, 5 cases of nephrostomy, 1 case of ureterectomy, 1 case of augmentation cystoplasty, and 1 case of transurethral resection of prostate. Conclusions The frequency of GUTB tended to decrease progressively. However, GUTB is still a threat to public health. There was no previous history of tuberculosis in two thirds of the cases of GUTB and more than half of them required further surgical treatment.",
"author_names": [
"Joo Yong Lee",
"Hee Young Park",
"Sung Yul Park",
"Seung Wook Lee",
"Hong Sang Moon",
"Yong Tae Kim",
"Tchun-Yong Lee",
"Hae Young Park"
],
"corpus_id": 17027806,
"doc_id": "17027806",
"n_citations": 19,
"n_key_citations": 2,
"score": 0,
"title": "Clinical Characteristics of Genitourinary Tuberculosis during a Recent 10 Year Period in One Center",
"venue": "Korean journal of urology",
"year": 2011
},
{
"abstract": "ABSTRACT The number of snakes donated to the Brazilian Instituto Butantan has been decreasing in the past 10 years. This circumstance motivated us to compare the properties of five venom pools of Bothrops jararaca snake stored for up to 54 years. Results showed differences among venom pools regarding enzymatic and other biological activities, such as caseinolytic, phospholipase A2, hemorrhagic and coagulant activities, as well as antigenicity. Protein content, reverse phase chromatographic profile, and immunorecognition by commercial Bothrops antivenom were comparable for all venom pools, although lethality of the most recent preparations was higher. Since the lowest functional activities did not always correspond to older venoms, differences among venom pools used for antivenom production during the period 1963 2008 may correlate with the different proportions of venoms from different localities used in their generation, rather than to long term storage. We conclude that B. jararaca venoms properly stored for long periods of time retain their structural and pharmacological activities, thus representing useful materials for scientific research and antivenom production. Graphical abstract Figure. No Caption available. HighlightsBioactivities of Bothrops jararaca venom pools stored for up to 54 years were analyzed.Protein content, chromatographic and immunorecognition profile were comparable for all venom pools.Lethality of lyophilized venom pools (1997 and 2008) was higher than that of venom pools dried at RT (1963, 1973, 1977 88).Vintage venom collections represent valuable materials for research purposes and possibly for the production of antivenom.",
"author_names": [
"Daniela Miki Hatakeyama",
"Karen de Morais-Zani",
"Caroline Serino-Silva",
"Kathleen Fernandes Grego",
"Savio Stefanini Sant'anna",
"Wilson Fernandes",
"Patricia Antonia Estima Abreu de Aniz",
"Ricardo Jose Soares Torquato",
"Aparecida S Tanaka",
"Libia Sanz",
"Juan J Calvete",
"Anita Mitico Tanaka-Azevedo"
],
"corpus_id": 25197028,
"doc_id": "25197028",
"n_citations": 6,
"n_key_citations": 0,
"score": 0,
"title": "Examination of biochemical and biological activities of Bothrops jararaca (Serpentes: Viperidae; Wied Neuwied 1824) snake venom after up to 54 years of storage",
"venue": "Toxicon official journal of the International Society on Toxinology",
"year": 2018
},
{
"abstract": "The promising and extraordinary properties of graphene have attracted significant interest, making graphene an alternative to replace many traditional materials for many applications, particularly in conductive ink for the fabrication of flexible electronics. For the past 10 years, numerous studies have been reported on the synthesis of graphene conductive ink for printing on flexible substrates for various electronic applications. The development of graphene based ink is reviewed, with the main focus on the types of graphene like materials in conductive inks, and the compositions and important properties of those inks. Another intention behind this review is to compare the pros and cons of graphene based ink with those using other common conductive materials, such as gold nanoparticles, silver nanoparticles, copper nanoparticles, conductive polymers and carbon nanotubes. Recent works on graphene hybrid based ink containing other metallic nanoparticles as an alternative way to improve the electrical properties of the conductive inks are also reported. Brief comparisons between inkjet printing and other printing techniques for the fabrication of flexible electronics are discussed.",
"author_names": [
"D S Saidina",
"Netnapa Eawwiboonthanakit",
"Mustapha Mariatti",
"Sebastien Fontana",
"Christian Herold"
],
"corpus_id": 146039627,
"doc_id": "146039627",
"n_citations": 25,
"n_key_citations": 0,
"score": 0,
"title": "Recent Development of Graphene Based Ink and Other Conductive Material Based Inks for Flexible Electronics",
"venue": "Journal of Electronic Materials",
"year": 2019
},
{
"abstract": "PurposeGrowing awareness of the environmental performance of construction products and buildings brings about the need for a suitable method to assess their environmental performance. Life cycle assessment (LCA) has become a widely recognised and accepted method to assess the burdens and impacts throughout the life cycle. This LCA based information may be in the form of environmental product declarations (EPD) or product environmental footprints (PEF) based on reliable and verifiable information. All of these use LCA to quantify and report several environmental impact categories and may also provide additional information. To better understand on the one hand existing EPD programmes (EN 15804) for each country and on the other the recent developments in terms of EU reference document (e.g. PEF) the authors decided to write this review paper based on the outcomes of the EPD workshop that was held prior to SB13 Graz conference.MethodsThis paper presents the state of the art in LCA and an overview of the EPD programmes in five European countries (Austria, Belgium, France, Germany, Switzerland) based on the workshop in the first part and a comprehensive description and comparison of the PEF method and EN 15804 in the second part. In the last part, a general conclusion will wrap up the findings and results will provide a further outlook on future activities.Results and discussionThe high number of EPD programmes underlines the fact that there is obviously a demand for assessments of the environmental performance of construction materials. In the comparison between and experiences of the different countries, it can be seen that more similarities than differences exist. A comparison between PEF and EPD shows differences, e.g. LCIA impact categories and recycling methodology.ConclusionsIndependent of raising awareness of the construction material environmental performance, the existence of so many environmental claims calls for clarification and harmonisation. Additionally, construction materials being assessed in the voluntary approaches have to follow the harmonised approach following the principles of the European Construction Products Regulation (regulated) not to foster barriers of trade. The authors therefore highly appreciate the most recent activities of the sustainability of construction works (CEN/TC 350 committee http:/portailgroupe.afnor.fr/public_espacenormalisation/CENTC350/index.html) currently working on these issues at the EU level. Finally, the LCA community is further encouraged to increase the background life cycle inventory data and life cycle inventory modelling as well as the meaningfulness of certain environmental impact categories, such as toxicity, land use, biodiversity and resource usage.",
"author_names": [
"Alexander Passer",
"S Lasvaux",
"Karen Allacker",
"Dieter De Lathauwer",
"Carolin Spirinckx",
"Bastian Wittstock",
"Daniel Kellenberger",
"Florian Gschosser",
"J N Wall",
"Holger Wallbaum"
],
"corpus_id": 14593031,
"doc_id": "14593031",
"n_citations": 82,
"n_key_citations": 3,
"score": 0,
"title": "Environmental product declarations entering the building sector: critical reflections based on 5 to 10 years experience in different European countries",
"venue": "The International Journal of Life Cycle Assessment",
"year": 2015
},
{
"abstract": "The advent of new technologies in the field of medicine and dentistry is giving improvements that lead the clinicians to have materials and procedures able to improve patients' quality of life. In dentistry, the last digital techniques offer a fully digital computerized workflow that does not include the standard multiple traditional phases. The purpose of this study is to evaluate all clinical trials and clinical randomized trials related to the digital or dental impression technique in prosthetic dentistry trying to give the readers global information about advantages and disadvantages of each procedure. Data collection was conducted in the main scientific search engines, including articles from the last 10 years, in order to obtain results that do not concern obsolete impression techniques. Elsevier, Pubmed and Embase have been screened as sources for performing the research. The results data demonstrated how the working time appears to be improved with digital workflow, but without a significant result (P 0.72596) The papers have been selected following the Population Intervention Comparison Outcome (PICO) question, which is related to the progress on dental impression materials and technique. The comparison between dentists or practitioners with respect to classic impression procedures, and students open to new device and digital techniques seem to be the key factor on the final impression technique choice. Surely, digital techniques will end up supplanting the analogical ones altogether, improving the quality of oral rehabilitations, the economics of dental practice and also the perception by our patients.",
"author_names": [
"Marco Cicciu'",
"Luca Fiorillo",
"Cesare D'Amico",
"Dario Gambino",
"Emanuele Mario Amantia",
"Luigi Laino",
"Salvatore Crimi",
"Paola Campagna",
"Alberto Bianchi",
"Alan Scott Herford",
"Gabriele Cervino"
],
"corpus_id": 216596217,
"doc_id": "216596217",
"n_citations": 16,
"n_key_citations": 0,
"score": 0,
"title": "3D Digital Impression Systems Compared with Traditional Techniques in Dentistry: A Recent Data Systematic Review",
"venue": "Materials",
"year": 2020
},
{
"abstract": "Purpose We studied the results of urine cultures and antimicrobial sensitivity tests according to the voiding method used by spinal cord injury (SCI) patients over a recent 10 year period. Materials and Methods We retrospectively analyzed 1,236 urine samples and their antimicrobial sensitivity tests for 112 patients who had used only one voiding method between January 2000 and December 2009. The voiding methods were classified into four groups: clean intermittent catheterization (CIC) suprapubic catheterization, urethral Foley catheter, and spontaneous voiding. Results Of the 1,236 urine samples, 925 (74.8% were positive and 279 (30.2% had more than one bacteria. The CIC group showed the lowest rate of bacteriuria, colony counts, and polymicrobial infection (p<0.001) Causative organisms were mostly Gram negative bacteria (84% including Pseudomonas aeruginosa (22.9% Escherichia coli (21.1% Klebsiella species (6.7% and Citrobacter species (6.3% The rate of Gram positive bacterial infection was 13.6% and major pathogenic organisms were Streptococcus species (8.6% and Staphylococcus species (2.6% Major pathogenic organisms and the results of antimicrobial sensitivity tests differed according to the voiding method. Conclusions Although the patient's condition and preferences are important when choosing the method of bladder management, CIC is the best voiding method for reducing urinary tract infections in SCI patients. When immediate use of antibiotics is needed for treatment of urinary tract infections, an appropriate antibiotic can be chosen according to the voiding method on the basis of our study and can be administered before the results of an antimicrobial sensitivity test are available.",
"author_names": [
"Kyoung Ho Ryu",
"Yun Beom Kim",
"Seung Ok Yang",
"Jeong Kee Lee",
"Tae Young Jung"
],
"corpus_id": 2849397,
"doc_id": "2849397",
"n_citations": 18,
"n_key_citations": 0,
"score": 0,
"title": "Results of Urine Culture and Antimicrobial Sensitivity Tests According to the Voiding Method Over 10 Years in Patients with Spinal Cord Injury",
"venue": "Korean journal of urology",
"year": 2011
}
] |
Voltage tracking of a DC-DC buck-boost converter using Gaussian fuzzy logic control | [
{
"abstract": "DC DC converters are the most widely used circuits in power electronics. They can be found in almost every electronic device nowadays, since all semiconductor components are powered by DC sources. DC DC converter usually consists of power semiconductor devices which are operated as electronic switches. Operation of the switching devices causes the inherently nonlinear characteristic to the dc dc converters including the buck boost converter. Proportional Integral Differential (PID) controllers have been usually applied to the dc dc converters because of their simplicity design. However, implementations of this control method to the nonlinear system such as the buck boost converters will suffer from dynamic response for the converter output. To achieve a stable and fast response, nonlinear controller were applied to control buck boost converters. Gaussian Fuzzy Logic Control (GFLC) was designed for the buck boost converters. MATLAB/Simulink was used as the platform in designing both of Gaussian Fuzzy Logic and PID controllers. The controllers performance are compared based on dynamic respond of the controllers in term of settling time (ts) overshoot ratio, peak time (tp) and voltage deviations. Based on simulation results, GFLC have a superior dynamic respond performance compare to PID controller. GFLC produced 0.02% overshoot ratio, 0% voltage deviation and lower setting time (36.08ms) which is a very good dynamic respond in order to achieve desired output voltage values for buck boost converter.",
"author_names": [
"Gadaffi Bin Omar"
],
"corpus_id": 110375271,
"doc_id": "110375271",
"n_citations": 1,
"n_key_citations": 0,
"score": 1,
"title": "VOLTAGE TRACKING OF A DC DC BUCK BOOST CONVERTER USING GAUSSIAN FUZZY LOGIC CONTROL",
"venue": "",
"year": 2012
},
{
"abstract": "DC DC converters are electronic devices used to change DC electrical power efficiently from one voltage level to another. Operation of the switching devices causes the inherently nonlinear characteristic of the DC DC converters including one known as the Boost converter. Consequently, this converter requires a controller with a high degree of dynamic response. Proportional Integral Differential (PID) controllers have been usually applied to the converters because of their simplicity. However, the main drawback of PID controller is unable to adapt and approach the best performance when applied to nonlinear system. It will sufer from dynamic response, produces overshoot, longer rise time and settling time which in turn will influenced the output voltage regulation of the Boost converter. Therefore, the implementation of practical Fuzzy Logic controller that will deal to the issue must be investigated. Fuzzy logic controller using voltage output as feedback for significantly improving the dynamic performance of boost dc dc converter by using MATLAB@Simulink software. The design and calculation of the components especially for the inductor has been done to ensure the converter operates in continuous conduction mode. The evaluation of the output has been carried out and compared by software simulation using MATLAB software between the open loop and closed loop circuit. The simulation results are shown that voltage output is able to be control in steady state condition for DC DC boost converter by using this methodology.Scope of this project limited only one types that is Gaussian membership function.",
"author_names": [
"S Jamali"
],
"corpus_id": 110636001,
"doc_id": "110636001",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Voltage tracking of DC DC boost converter using Gaussian Fuzzy Logic Controller",
"venue": "",
"year": 2012
},
{
"abstract": "Renewable energy is becoming more popular every day. This is mainly attributed to threats that fossil fuels pose towards the climate change, and also the fact that they are scarce. Thus, solutions such as solar energy are among the top trending alternatives to the fossil fuels. However, one of the main issues with solar energy, particularly with its most popular technique, the photovoltaic solar arrays, is that they are not efficient when it comes to their ratio of power to cost. In order to address this problem, we propose a voltage regulation system that enhances photovoltaic system. The main feature of this system is that it uses a DC DC converter that regulates the power using specific voltage inputs. Combining this system with Maximum Power Point Tracking (MPPT) the efficiency of the photovoltaic panels to reach its maximum capacity. The voltage is regulated using a buck and boost converter. In order to simulate the environment, MATLAB SIMULINK is used for developing and implementing the system, as well as applying the algorithms related to the fuzzy logic controller for Pulse Width Modulation (PWM) signal generation on the converter. The results indicated that using fuzzy logic technique is an effective method for the increasing the photovoltaic system power to cost efficiency. Other than being a novel technique, the fuzzy logic strategy is also robust and adaptable, which allows it to be combined with a multitude of systems.",
"author_names": [
"Baqer Turki Attayah",
"Ali Idham Alzaidi",
"Naib Fasel",
"Mohammad Rava"
],
"corpus_id": 234478616,
"doc_id": "234478616",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Enhancing the Photovoltaic System Output Performance Through the Use of Maximum Power Point Tracking and Fuzzy Logic Control",
"venue": "2021 IEEE International Conference in Power Engineering Application (ICPEA)",
"year": 2021
},
{
"abstract": "This paper demonstrates a novel method to integrate and control PV source and Battery storage in to a microgrid system to attain reduction in total harmonic distortion at the output. The closed loop control of inverter has been achieved through using proportional integral controller (PI) and fuzzy logic controller. The results of output harmonics contents are compared for simple open loop control and proposed closed loop controls, and it clearly indicates that the closed loop results far superior in terms of harmonic contents at the inverter output voltage. The control of battery energy storage system (BESS) has been presented, with the aid of a DC DC bidirectional buck boost converter for the different modes of operation, such as hold state, charging state and discharging state. With the intention of tracking the maximum power point from PV array, P&O MPPT technique has been used by which duty cycle of converter is controlled. Various operating conditions, such as photovoltaic source alone supplying to the entire load requirement and supplying to battery for its charging, PV source supplying to load requirement only, battery storage unit supplying to load requirement and lastly PV source and battery storage unit jointly supplying to the load requirement, have been analyzed extensively. Detailed analysis has been carried out on the output voltage, output current and output power waveforms for different operating conditions as discussed above, and the output results are analyzed for achieving more beneficial performance of the system. The suggested microgrid energy management system has been modeled and analyzed using MATLAB/Simulink tool.",
"author_names": [
"Swaminathan Ganesan",
"V Ramesh",
"Subramaniam Umashankar",
"Padmanaban Sanjeevikumar"
],
"corpus_id": 56720188,
"doc_id": "56720188",
"n_citations": 12,
"n_key_citations": 0,
"score": 0,
"title": "Fuzzy Based Microgrid Energy Management System Using Interleaved Boost Converter and Three Level NPC Inverter with Improved Grid Voltage Quality",
"venue": "",
"year": 2018
},
{
"abstract": "Photovoltaic (PV) power generation has characteristics of uncertainty and intermittence due to varying irradiances and temperatures. Maximum Power Point Tracking (MPPT) algorithm in a DC/DC converter ensures the PV is able to generate its maximum power according to its power voltage curve. This paper proposes a novel method based on Fuzzy Logic System (FLS) to tune the control gains. Sixty three scenarios considering varying insolation and temperature from nine Taguchi's orthogonal experiments are studied to achieve a robust design of control gains. The obtained optimal control gains of FLS hence can be applied to different meteorological conditions. A standalone PV system with a boost converter and load is used to show the applicability of the proposed method.",
"author_names": [
"Ying-Yi Hong",
"Peter Mark P Buay",
"Angelo A Beltran"
],
"corpus_id": 201743054,
"doc_id": "201743054",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Maximum Power Point Tracking of Photovoltaic System Using Taguchi based Fuzzy Logic Control",
"venue": "2019 IEEE Milan PowerTech",
"year": 2019
},
{
"abstract": "Due to the concern with energy emergencies, the energy obtained from the sunlight is considered as the most capable conventional resources. Hence, the maximum power point tracking approach is necessary for obtaining the enhanced efficiency from the solar panels. In the case of direct current (DC) application, the output obtained from the photo voltaic (PV) array cannot be directly connected to the electronic devices. For regulating the output from the PV array, the DC DC converter is provided in between the load and the array. The converter design plays a significant role to track the maximum power point of the solar panel. This paper describes the design of three converters, namely the boost, buck boost and buck converter, along with the fuzzy logic controller. It varies the time for switching ON and OFF of the converter concerning changes in the solar panel power. The result of converter power and solar panel for different irradiation is compared for various DC DC converters. The fuzzy logic controller is employed in the generation of optimal control pulse for the DC DC converter. Moreover, in the solar photovoltaic system, the steady state operation is performed and the various solar irradiance results are analyzed. The proposed approach is compared with the various DC DC converters like buck boost converter, buck converter and boost converter to prove the efficiency. Then, the performance analysis of the current, voltage and power of PV is analyzed.",
"author_names": [
"A Rajavel",
"N Rathina Prabha"
],
"corpus_id": 225190799,
"doc_id": "225190799",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Fuzzy logic controller based boost and buck boost converter for maximum power point tracking in solar system",
"venue": "Trans. Inst. Meas. Control",
"year": 2021
},
{
"abstract": "DC DC converters are used in many application such solar battery system, dc motor drives etc. DC DC converters are used to convert the unregulated dc voltage into regulated dc voltage .The performance of these types of converters are best choice of control methods. Traditional methods require a mathematical model for a system but the fuzzy logic controller doesn't require any mathematical model and very simple to implement .The main objective of this work to reduce the overshoot of these types of converters. This work concentrates on buck boost and cuk converter. The buck boost and cuk converter is simulated for different R Loads and their output voltage is settle at desired voltage .The performance of buck boost and cuk converter are simulated using Matlab/Simulink and comparison study is performed.",
"author_names": [
"A Geetha"
],
"corpus_id": 110881393,
"doc_id": "110881393",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Comparison of Buck Boost and CUK Converter Control Using Fuzzy Logic Controller",
"venue": "",
"year": 2014
},
{
"abstract": "Abstract Z source converters are recently premised DC DC converters which can perform buck and boost operations, offer greater range of DC output voltage, high reliability and reduce in rush and ripple currents. In photovoltaic (PV) applications, they provide better results compared to conventional DC DC converters. These converters can be used as power conditioning units, so that the voltage boost and reception of maximum power from the PV array can be achieved. The maximum power point tracking (MPPT) is here achieved by controlling the duty cycle of the converter. A fuzzy logic control based MPPT is developed in this work to track the maximum power point of the PV array under variable solar irradiance and temperature conditions. MATLAB simulation and experimental results are given to establish the developed system.",
"author_names": [
"U Shajith Ali"
],
"corpus_id": 114006025,
"doc_id": "114006025",
"n_citations": 16,
"n_key_citations": 1,
"score": 0,
"title": "Z source DC DC Converter with Fuzzy Logic MPPT Control for Photovoltaic Applications",
"venue": "",
"year": 2016
},
{
"abstract": "Abstract The paper presents a hybrid system comprising of photovoltaic (PV) and battery with fuzzy logic control (FLC) to meet the demands of isolated off grid DC loads. Perturb and Observe (P&O) method is used to achieve the maximum power point tracking (MPPT) by controlling the duty cycle of a dc dc boost converter. Fuzzy logic controller regulates the power flow of the battery by means of a bidirectional buck boost converter. The complete energy management system has been validated in MATLAB/SIMUINK with variable solar irradiation profile. The simulation results show that the system with fuzzy logic control prolongs the battery lifespan by reducing the battery peak current up to 0.22% and also significantly decreases the settling time and peak overshoot of the DC load voltage up to 16.23% and 14.62% as compared to the system with conventional PID control.",
"author_names": [
"Neerparaj Rai",
"Bijay Rai"
],
"corpus_id": 117307428,
"doc_id": "117307428",
"n_citations": 18,
"n_key_citations": 0,
"score": 0,
"title": "Control of fuzzy logic based PV battery hybrid system for stand alone DC applications",
"venue": "",
"year": 2018
},
{
"abstract": "The test with solar energy extraction are talked in the planned methodthrough improvement and demo of multilevel inverter architecture andthe connected controller algorithms. The planned multilevel invertertopology along with the control algorithms for solar photovoltaic (PV)systems growths the overall energy capture from the sun. Multilevelinverters are frequently used in medium and high power applicationsbecause of their strength and dependability. In real the energy demandcatastrophes in the current scenario will actually raise its demandhence these are the obligatory purposes in the economy growth of thecountry. PV arrays are castoff to make the electricity by using sunlight orirradiation and temperature for maximum power output MPPT are castoffwith SEPIC converters. The multilevel inverters have been familiarized anarray of power semiconductor switches with several lower DC voltagesources. Hence multilevel inverters are developing out as anothersolution for high and medium power voltage levels. PV (photovoltaic)system With Single Ended Primary Inductor Converter(SEPIC) andMaximum Power Point Tracking (MPPT) using fuzzy logic controller withproper constraints clear for algorithm are available here to solve theharmonic problem of PV system. Fuzzy logic controller demonstrationshigh precision in current transition and gives crisp output to the SEPICconverter for buck/boost the output voltage of PV array. FLC foundedon madmen technique and gives duty cycle to the SEPIC converter forboost up the output voltage of PV array so SEPIC converter also knownas dc to dc converter or buck/boost converter, inverters are used forconversion of dc to ac but for reduction of harmonics, multilevel inverteris used in this paper since, it gives near to sine wave with less harmonicoutput and increasing the higher order inverters we can more controlthe output waveform",
"author_names": [
"A Raghu Rama Chandra",
"Harpreet Kaur Dalgit Singh"
],
"corpus_id": 225579891,
"doc_id": "225579891",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Fuzzy Logic Constructed on Sepic Converter For Maximum Power Point Tracking With Five Level Inverter",
"venue": "",
"year": 2020
}
] |
The chemistry of two-dimensional layered transition metal dichalcogenide nanosheets | [
{
"abstract": "Ultrathin two dimensional nanosheets of layered transition metal dichalcogenides (TMDs) are fundamentally and technologically intriguing. In contrast to the graphene sheet, they are chemically versatile. Mono or few layered TMDs obtained either through exfoliation of bulk materials or bottom up syntheses are direct gap semiconductors whose bandgap energy, as well as carrier type (n or p type) varies between compounds depending on their composition, structure and dimensionality. In this Review, we describe how the tunable electronic structure of TMDs makes them attractive for a variety of applications. They have been investigated as chemically active electrocatalysts for hydrogen evolution and hydrosulfurization, as well as electrically active materials in opto electronics. Their morphologies and properties are also useful for energy storage applications such as electrodes for Li ion batteries and supercapacitors.",
"author_names": [
"Manish Chhowalla",
"Hyeon Suk Shin",
"Goki Eda",
"Lain-Jong Li",
"Kian Ping Loh",
"Hua Zhang"
],
"corpus_id": 205291228,
"doc_id": "205291228",
"n_citations": 5976,
"n_key_citations": 50,
"score": 1,
"title": "The chemistry of two dimensional layered transition metal dichalcogenide nanosheets.",
"venue": "Nature chemistry",
"year": 2013
},
{
"abstract": "Ultrathin two dimensional (2D) nanosheets of layered transition metal dichalcogenides (TMDs) such as MoS2, TiS2, TaS2, WS2, MoSe2, WSe2, etc. are emerging as a class of key materials in chemistry and electronics due to their intriguing chemical and electronic properties. The ability to prepare these TMD nanosheets in high yield and large scale via various methods has led to increasing studies on their hybridization with other materials to create novel functional composites, aiming to engineer their chemical, physical and electronic properties and thus achieve good performance for some specific applications. In this critical review, we will introduce the recent progress in hybrid nanoarchitectures based on 2D TMD nanosheets. Their synthetic strategies, properties and applications are systematically summarized and discussed, with emphasis on those new appealing structures, properties and functions. In addition, we will also give some perspectives on the challenges and opportunities in this promising research area.",
"author_names": [
"Chaoliang Tan",
"Hua Zhang"
],
"corpus_id": 8426151,
"doc_id": "8426151",
"n_citations": 933,
"n_key_citations": 3,
"score": 0,
"title": "Two dimensional transition metal dichalcogenide nanosheet based composites.",
"venue": "Chemical Society reviews",
"year": 2015
},
{
"abstract": "Group 6 transition metal dichalcogenides (G6 TMDs) most notably MoS2, MoSe2, MoTe2, WS2 and WSe2, constitute an important class of materials with a layered crystal structure. Various types of G6 TMD nanomaterials, such as nanosheets, nanotubes and quantum dot nano objects and flower like nanostructures, have been synthesized. High thermodynamic stability under ambient conditions, even in atomically thin form, made nanosheets of these inorganic semiconductors a valuable asset in the existing library of two dimensional (2D) materials, along with the well known semimetallic graphene and insulating hexagonal boron nitride. G6 TMDs generally possess an appropriate bandgap (1 2 eV) which is tunable by size and dimensionality and changes from indirect to direct in monolayer nanosheets, intriguing for (opto)electronic, sensing, and solar energy harvesting applications. Moreover, rich intercalation chemistry and abundance of catalytically active edge sites make them promising for fabrication of novel energy storage devices and advanced catalysts. In this review, we provide an overview on all aspects of the basic science, physicochemical properties and characterization techniques as well as all existing production methods and applications of G6 TMD nanomaterials in a comprehensive yet concise treatment. Particular emphasis is placed on establishing a linkage between the features of production methods and the specific needs of rapidly growing applications of G6 TMDs to develop a production application selection guide. Based on this selection guide, a framework is suggested for future research on how to bridge existing knowledge gaps and improve current production methods towards technological application of G6 TMD nanomaterials.",
"author_names": [
"Morasae Samadi",
"N Sarikhani",
"Mohammad Zirak",
"Hua Zhang",
"Alireza Z Moshfegh"
],
"corpus_id": 189729470,
"doc_id": "189729470",
"n_citations": 146,
"n_key_citations": 1,
"score": 0,
"title": "Group 6 transition metal dichalcogenide nanomaterials: synthesis, applications and future perspectives.",
"venue": "Nanoscale horizons",
"year": 2018
},
{
"abstract": "Semimetallic layered transition metal dichalcogenides, such as TiS2, can serve as a platform material for exploring novel physics modulated by dimensionality, as well as for developing versatile applications in electronics and thermoelectrics. However, controlled synthesis of ultrathin TiS2 in a dry chemistry way has yet to be realized because of the high oxophilicity of active Ti precursors. Here, we report the ambient pressure chemical vapor deposition (CVD) method to grow large size, highly crystalline two dimensional (2D) TiS2 nanosheets through in situ generating titanium chloride as the gaseous precursor. The addition of NH4Cl promoter can react with Ti powders and switch the solid phase sulfurization reaction into a CVD process, thus enabling the controllability over the size, shape, and thickness of the TiS2 nanosheets via tuning the synthesis conditions. Interestingly, this semimetallic 2D material exhibits near infrared surface plasmon resonance absorption and a memristor like electrical behavior, both holding promise for further application developments. Our method hence opens a new avenue for the CVD growth of 2D metal dichalcogenides directly from metal powders and pave the way for exploring their intriguing properties and applications.",
"author_names": [
"Zhenfei Gao",
"Qingqing Ji",
"Pin-Chun Shen",
"Yimo Han",
"Wei Sun Leong",
"Nannan Mao",
"Lin Zhou",
"Cong Su",
"Jingjing Niu",
"Xiang Ji",
"Mahomed Mehdi Goulamaly",
"David A Muller",
"Yongfeng Li",
"Jing Kong"
],
"corpus_id": 206493319,
"doc_id": "206493319",
"n_citations": 10,
"n_key_citations": 0,
"score": 0,
"title": "In Situ Generated Volatile Precursor for CVD Growth of a Semimetallic 2D Dichalcogenide.",
"venue": "ACS applied materials interfaces",
"year": 2018
},
{
"abstract": "In this report, we will provide a comprehensive introduction to the investigations on the combination of elemental junction and planar heterostructure in TMDCs in terms of preparation and characterization mechanisms.",
"author_names": [
"Kun Chen",
"Li Tao",
"Xi Wan",
"Jianbin Xu"
],
"corpus_id": 213261796,
"doc_id": "213261796",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Preparation and Characterization of Two Dimensional Layered Transition Metal Dichalcogenide Thin Films",
"venue": "",
"year": 2019
},
{
"abstract": "Transition metal dichalcogenide (TMD) monolayers and heterostructures have emerged as a compelling class of materials with transformative properties that may be harnessed for novel device technolog.",
"author_names": [
"Tanushree H Choudhury",
"Xiaotian Zhang",
"Zakaria Y Al Balushi",
"Mikhail Chubarov",
"Joan M Redwing"
],
"corpus_id": 202540441,
"doc_id": "202540441",
"n_citations": 18,
"n_key_citations": 1,
"score": 0,
"title": "Epitaxial Growth of Two Dimensional Layered Transition Metal Dichalcogenides",
"venue": "",
"year": 2020
},
{
"abstract": "MoS2, MoSe2 and WSe2 thin flakes were fabricated by the standard micromechanical cleavage procedures. The thickness and the optical contrast of the atomic thin dichalcogenide flakes on SiO2/Si substrates were measured by atomic force microscopy (AFM) and spectroscopic ellipsometer. A rapid and nondestructive method by using reflection spectra was proposed to identify the layer number of 2D layered transition metal dichalcogenides on SiO2 (275 nm)/Si substrates. The contrast spectra of 2D nanosheets with different layer numbers are in agreement with theoretical calculations based on Fresnel's law, indicating that this method provides an unambiguous and nondestructive contrast spectra fingerprint for identifying single and few layered transition metal dichalcogenides. The results will greatly help in fundamental research and application.",
"author_names": [
"Jia-Peng Wu",
"Le Wang",
"Li-Yuan Zhang"
],
"corpus_id": 136284272,
"doc_id": "136284272",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "Rapid and nondestructive layer number identification of two dimensional layered transition metal dichalcogenides",
"venue": "Rare Metals",
"year": 2017
},
{
"abstract": "This special issue is about two dimensional transition metal dichalcogenides (2D TMDs) a family of materials consisting of over 40 compounds with the generalized formula of MX2, where M is a transition metal typically from groups 4 7, and X is a chalcogen such as S, Se or Te. Bulk TMDs have been widely studied over several decades because it is possible to formulate compounds with disparate electronic structures. In the bulk form, MX2 compounds are layered materials (or van der Waals solids) in which there is strong intralayer bonding and weak interlayer bonding. Each individual layer of the TMDs consists of three atomic layers in which the transition metal is sandwiched by two chalcogens. Furthermore, the chalcogen atoms are saturated and therefore are not highly reactive. These features allow for the attainment of individual layers of the TMDs by several exfoliation or vapor deposition methods. The isolation of monolayers of TMDs leads to the dramatic changes in their properties, primarily due to the confinement of charge carriers in two dimensions (xand y directions) due to the absence of interactions in the z direction. Thus, singlelayered nanosheets are two dimensional materials that possess dramatically different a Materials Science and Engineering, Rutgers University, 607 Taylor Road, Piscataway, NJ 08854, USA. E mail: [email protected] b Center for Nanochemistry (CNC) Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, People's Republic of China. E mail: [email protected] c School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore. E mail: [email protected]",
"author_names": [
"Manish Chhowalla",
"Zhongfan Liu",
"Hua Zhang"
],
"corpus_id": 39679892,
"doc_id": "39679892",
"n_citations": 433,
"n_key_citations": 0,
"score": 0,
"title": "Two dimensional transition metal dichalcogenide (TMD) nanosheets.",
"venue": "Chemical Society reviews",
"year": 2015
},
{
"abstract": "Recently there have been many research breakthroughs in two dimensional (2D) materials including graphene, boron nitride (h BN) black phosphors (BPs) and transition metal dichalcogenides (TMDCs) The unique electrical, optical, and thermal properties in 2D materials are associated with their strictly defined low dimensionalities. These materials provide a wide range of basic building blocks for next generation electronics. The chemical vapor deposition (CVD) technique has shown great promise to generate high quality TMDC layers with scalable size, controllable thickness, and excellent electronic properties suitable for both technological applications and fundamental sciences. The capability to precisely engineer 2D materials by chemical approaches has also given rise to fascinating new physics, which could lead to exciting new applications. In this Review, we introduce the latest development of TMDC synthesis by CVD approaches and provide further insight for the controllable and reliable synthesis of atomically thin TMDCs. Understanding of the vapor phase growth mechanism of 2D TMDCs could benefit the formation of complicated heterostructures and novel artificial 2D lattices.",
"author_names": [
"Henan Li",
"Ying Li",
"Areej Aljarb",
"Yumeng Shi",
"Lain-Jong Li"
],
"corpus_id": 28453913,
"doc_id": "28453913",
"n_citations": 162,
"n_key_citations": 1,
"score": 0,
"title": "Epitaxial Growth of Two Dimensional Layered Transition Metal Dichalcogenides: Growth Mechanism, Controllability, and Scalability.",
"venue": "Chemical reviews",
"year": 2018
},
{
"abstract": "Owing to an ultrathin body, atomic scale smoothness, dangling bond free surface, and sizable bandgap, transistors based on two dimensional (2D) layered semiconductors show the potential of scalability down to the nanoscale, high density three dimensional integration, and superior performance in terms of better electrostatic control and smaller power consumption compared with conventional three dimensional semiconductors (Si, Ge, and III V compound materials) To apply 2D layered materials into complementary metal oxide semiconductor logic circuits, it is important to modulate the carrier type and density in a controllable manner, and engineer the contact (between metal electrode and 2D semiconductor) and the interface (between dielectrics and semiconducting channel) to get close to their intrinsic carrier mobility. In this review, the most widely studied 2D transition metal dichalcogenides (TMD) are focused on, and an overview of recent progress on doping, contact, and interface engineering of the TMD based field effect transistors is provided.",
"author_names": [
"Yuda Zhao",
"Kang Xu",
"Feng Pan",
"Changjian Zhou",
"Feichi Zhou",
"Yang Chai"
],
"corpus_id": 99724297,
"doc_id": "99724297",
"n_citations": 112,
"n_key_citations": 1,
"score": 0,
"title": "Doping, Contact and Interface Engineering of Two Dimensional Layered Transition Metal Dichalcogenides Transistors",
"venue": "",
"year": 2017
}
] |
A high dielectric constant non-fullerene acceptor for efficient bulk-heterojunction organic solar cells | [
{
"abstract": "The majority of organic semiconductors have a low relative dielectric constant (er 6) has attracted a very limited attention. Moreover, high performance OSCs based on high dielectric constant photovoltaic materials are still in their infancy. Herein, we report an oligoethylene oxide side chain containing non fullerene acceptor (ITIC OE) with a high relative dielectric constant of er 9.4, which is two times larger than that of its alkyl chain containing counterpart ITIC. Encouragingly, the OSCs based on ITIC OE show a high power conversion efficiency of 8.5% which is the highest value for OSCs that employ high dielectric constant materials. Nevertheless, this value is lower than those of ITIC based control devices. The less phase separated morphology in blend films due to the reduced crystallinity of ITIC OE and the too good miscibility between PBDB T and ITIC OE are responsible for the lower device performance. This work suggests additional prerequisites to make high dielectric constants play a significant role in OSCs.",
"author_names": [
"Xi Liu",
"Boming Xie",
"Chunhui Duan",
"Zhaojing Wang",
"Baobing Fan",
"Kai Zhang",
"Baojun Lin",
"Fallon J M Colberts",
"Wei Ma",
"Raj Rene Janssen",
"Fei Huang",
"Yong Cao"
],
"corpus_id": 104181688,
"doc_id": "104181688",
"n_citations": 124,
"n_key_citations": 0,
"score": 1,
"title": "A high dielectric constant non fullerene acceptor for efficient bulk heterojunction organic solar cells",
"venue": "",
"year": 2018
},
{
"abstract": "An all carbon non fullerene electron acceptor material based on diindeno[1,2 g:1',2' s]rubicene (DIR) was readily synthesized and processed for bulk heterojunction organic solar cells. High PCE up to 3.05% with a relatively high VOC of 1.22 V has been achieved with P3HT electron donor material by the variation of donor acceptor blending ratio.",
"author_names": [
"Hung-Yang Chen",
"Jan Golder",
"Shih-Chieh Yeh",
"Chiao-Wen Lin",
"Chao-Tsen Chen",
"Chin-Ti Chen"
],
"corpus_id": 95083515,
"doc_id": "95083515",
"n_citations": 24,
"n_key_citations": 0,
"score": 0,
"title": "Diindeno[1,2 g:1',2' s]rubicene: all carbon non fullerene electron acceptor for efficient bulk heterojunction organic solar cells with high open circuit voltage",
"venue": "",
"year": 2015
},
{
"abstract": "Abstract Fluorination of molecular donors and acceptors enables an effective tuning of the energetics in organic bulk heterojunctions, leading to enhanced power conversion efficiencies in organic solar cells with non fullerene acceptors. To date, the impacts of fluorination on the dielectric properties and the key processes of charge dissociation and recombination are still poorly understood. Based on the fluorinated PBDBT 2F donor and IT 4F acceptor with a favorably enhanced dielectric constant in the blend films, we explore key factors attributing to the realized high fill factor (0.745) and efficiency (13.4% in the solar cells. Through comparing the IT 4F solar cell to that with non fluorinated ITIC acceptor, we identify distinct recombination profiles in the IT 4F based device that exhibits a highly efficient charge dissociation together with a small reduction factor (3.71 x10 2) for bi molecular recombination and a low recombination coefficient of 2.404 x 10 13 cm 3 s 1. These particularities lead to an ultrafast carrier sweepout",
"author_names": [
"Xuning Zhang",
"Dongyang Zhang",
"Qian Zhou",
"Rong Wang",
"Jiyu Zhou",
"Jianqiu Wang",
"Huiqiong Zhou",
"Yuan Zhang"
],
"corpus_id": 106124401,
"doc_id": "106124401",
"n_citations": 38,
"n_key_citations": 0,
"score": 0,
"title": "Fluorination with an enlarged dielectric constant prompts charge separation and reduces bimolecular recombination in non fullerene organic solar cells with a high fill factor and efficiency 13%",
"venue": "Nano Energy",
"year": 2019
},
{
"abstract": "Interlayers and interface engineering plays a pivotal role in achieving efficient charge extraction necessary for realizing high power conversion efficiency (PCE) in bulk heterojunction organic solar cells. In this study, we report a novel strategy of combining advantages of both fullerene derivative and non fullerene acceptor materials by employing solution processable non fullerene acceptor 3,9 bis(2 methylene (3 (1,1 dicyanomethylene) indan one) 5,5,11,11 tetrakis(4 hexylphenyl) dithieno[2,3 d:2',3' d' s indaceno[1,2 b:5,6 b']dithiophene (ITIC) to modify the interface between ZnO based electron transport layer and poly[4,8 bis(5 (2 ethylhexyl)thiophen 2 yl) benzo [1,2 b;4,5 b' dithiophe ne 2,6 diyl alt (4 (2 ethylhexyl) 3 fluorothieno[3,4 b]thiophene 2 carb oxylate 2 6 diyl) (PTB7 Th) phenyl C71 butyric acid methyl ester based photoactive layer. An improvement in PCE from 7.5% to 9% has been achieved for the devices with ITIC modified interlayer. Time resolved photoluminescence (PL) via time correlated single photon counting and photo electrochemical impedance spectroscopy (photo EIS) measurements were carried out to investigate the causes for improved PCE for the devices with ITIC modified interlayer.",
"author_names": [
"Kunal Borse",
"Ramakant Sharma",
"Dipti Gupta",
"Aswani Yella"
],
"corpus_id": 199125897,
"doc_id": "199125897",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "High Efficiency Organic Solar Cells With Solution Processable Non Fullerene Acceptor as an Interlayer",
"venue": "IEEE Journal of Photovoltaics",
"year": 2019
},
{
"abstract": "A significant leap in record breaking power conversion efficiencies (PCEs) of single junction bulk heterojunction (BHJ) organic solar cells (OSCs) to over 18%[1] has recently been achieved. This can be credited to the rapid developments of new non fullerene acceptors (NFAs) paired with suitable high performing polymer donors. While these breakthroughs are encouraging, it remains crucial to attain a deeper and more comprehensive understanding of the underlying mechanisms governing these novel and high performing polymer:NFA systems. Several recent studies have attributed the high performances of NFA based solar cells to an improvement in the open circuit voltage (VOC) without significantly diminishing the charge generation efficiency.[2 4] Particularly, in polymer:NFA systems, high VOC values have been achieved with efficient charge generation regardless of a very small energetic driving force for Even though significant breakthroughs with over 18% power conversion efficiencies (PCEs) in polymer:non fullerene acceptor (NFA) bulk heterojunction organic solar cells (OSCs) have been achieved, not many studies have focused on acquiring a comprehensive understanding of the underlying mechanisms governing these systems. This is because it can be challenging to delineate device photophysics in polymer:NFA blends comprehensively, and even more complicated to trace the origins of the differences in device photophysics to the subtle differences in energetics and morphology. Here, a systematic study of a series of polymer:NFA blends is conducted to unify and correlate the cumulative effects of i) voltage losses, ii) charge generation efficiencies, iii) non geminate recombination and extraction dynamics, and iv) nuanced morphological differences with device performances. Most importantly, a deconvolution of the major loss processes in polymer:NFA blends and their connections to the complex BHJ morphology and energetics are established. An extension to advanced morphological techniques, such as solid state NMR (for atomic level insights on the local ordering and donor:acceptor pp interactions) and resonant soft X ray scattering (for donor and acceptor interfacial area and domain spacings) provide detailed insights on how efficient charge generation, transport, and extraction processes can outweigh increased voltage losses to yield high PCEs.",
"author_names": [
"Akchheta Karki",
"Joachim Vollbrecht",
"Alexander J Gillett",
"Philipp Selter",
"Jaewon Lee",
"Zhengxing Peng",
"Nora Schopp",
"Alana L Dixon",
"Max Schrock",
"Vojtech Nadazdy",
"Franz Schauer",
"Harald W Ade",
"Bradley F Chmelka",
"Guillermo C Bazan",
"Richard H Friend",
"Thuc-Quyen Nguyen"
],
"corpus_id": 225659757,
"doc_id": "225659757",
"n_citations": 23,
"n_key_citations": 0,
"score": 0,
"title": "Unifying Charge Generation, Recombination, and Extraction in Low Offset Non Fullerene Acceptor Organic Solar Cells",
"venue": "",
"year": 2020
},
{
"abstract": "In bulk heterojunction (BHJ) organic solar cells (OSCs) both the electron affinity (EA) and ionization energy (IE) offsets at the donor acceptor interface should equally control exciton dissociation. Here, we demonstrate that in low bandgap non fullerene acceptor (NFA) BHJs ultrafast donor to acceptor energy transfer precedes hole transfer from the acceptor to the donor and thus renders the EA offset virtually unimportant. Moreover, sizeable bulk IE offsets of about 0.5 eV are needed for efficient charge transfer and high internal quantum efficiencies, since energy level bending at the donor NFA interface caused by the acceptors' quadrupole moments prevents efficient exciton to charge transfer state conversion at low IE offsets. The same bending, however, is the origin of the barrier less charge transfer state to free charge conversion. Our results provide a comprehensive picture of the photophysics of NFA based blends, and show that sizeable bulk IE offsets are essential to design efficient BHJ OSCs based on low bandgap NFAs. A systematic analysis of a series of donor acceptor organic blends shows that in solar cells based on low bandgap non fullerene acceptors an ionization energy offset of about 0.5 eV is required to ensure efficient charge separation.",
"author_names": [
"Safakath Karuthedath",
"Julien Gorenflot",
"Yuliar Firdaus",
"Neha Chaturvedi",
"Catherine S P De Castro",
"George T Harrison",
"Jafar Iqbal Khan",
"Anastasia A Markina",
"Ahmed Hesham Balawi",
"Top Archie Dela Pena",
"Wenlan Liu",
"Ru-Ze Liang",
"Anirudh Sharma",
"Sri H K Paleti",
"Weimin Zhang",
"Yuanbao Lin",
"Erkki Alarousu",
"Dalaver Hussain Anjum",
"Pierre M Beaujuge",
"Stefaan De Wolf",
"Iain McCulloch",
"Thomas D Anthopoulos",
"Derya Baran",
"Denis Andrienko",
"Frederic Laquai"
],
"corpus_id": 225072638,
"doc_id": "225072638",
"n_citations": 31,
"n_key_citations": 0,
"score": 0,
"title": "Intrinsic efficiency limits in low bandgap non fullerene acceptor organic solar cells",
"venue": "Nature Materials",
"year": 2020
},
{
"abstract": "Organic solar cells are currently experiencing a second golden age thanks to the development of novel non fullerene acceptors (NFAs) Surprisingly, some of these blends exhibit high efficiencies despite a low energy offset at the heterojunction. Herein, free charge generation in the high performance blend of the donor polymer PM6 with the NFA Y6 is thoroughly investigated as a function of internal field, temperature and excitation energy. Results show that photocurrent generation is essentially barrierless with near unity efficiency, regardless of excitation energy. Efficient charge separation is maintained over a wide temperature range, down to 100 K, despite the small driving force for charge generation. Studies on a blend with a low concentration of the NFA, measurements of the energetic disorder, and theoretical modeling suggest that CT state dissociation is assisted by the electrostatic interfacial field which for Y6 is large enough to compensate the Coulomb dissociation barrier.",
"author_names": [
"Lorena Perdigon-Toro",
"Huotian Zhang",
"Anastasia A Markina",
"Jun Yuan",
"Seyed Mehrdad Hosseini",
"Christian M Wolff",
"Guangzheng Zuo",
"Martin Stolterfoht",
"Yingping Zou",
"Feng Gao",
"Denis Andrienko",
"Safa Shoaee",
"Dieter Neher"
],
"corpus_id": 210881793,
"doc_id": "210881793",
"n_citations": 91,
"n_key_citations": 0,
"score": 0,
"title": "Barrierless Free Charge Generation in the High Performance PM6:Y6 Bulk Heterojunction Non Fullerene Solar Cell.",
"venue": "Advanced materials",
"year": 2020
},
{
"abstract": "Non fullerene acceptors (NFAs) have recently outperformed their fullerene counterparts in binary bulk heterojunction (BHJ) organic solar cells (OSCs) Further development of NFA OSCs may benefit other novel OSC device structures that alter or extend the standard BHJ concept. Here, we report such a new processing route that forms a BHJ like morphology between sequentially processed polymer donor and NFA with high power conversion efficiencies in excess of 10% Both devices show similar charge generation and recombination behaviours, supporting formation of similar BHJ active layers. We correlate the ~30 meV smaller open circuit voltage in sq BHJ devices to more substantial non radiative recombination by voltage loss analysis. We also determine the exciton diffusion length of benchmark polymer PBDB T to be 10 3 nm. Our results demonstrate high efficiency OSC devices using sequential deposition method and provide new opportunities to further improve performance of state of the art OSCs.",
"author_names": [
"Jiangbin Zhang",
"Bin Kan",
"Andrew J Pearson",
"Andrew J Parnell",
"Joshaniel F K Cooper",
"Xiao-Ke Liu",
"Patrick J Conaghan",
"Thomas R Hopper",
"Yutian Wu",
"Xiangjian Wan",
"Feng Gao",
"Neil C Greenham",
"Artem A Bakulin",
"Yongsheng Chen",
"Richard H Friend"
],
"corpus_id": 105750803,
"doc_id": "105750803",
"n_citations": 27,
"n_key_citations": 0,
"score": 0,
"title": "Efficient non fullerene organic solar cells employing sequentially deposited donor acceptor layers",
"venue": "",
"year": 2018
},
{
"abstract": "A solution processable, non fullerene electron acceptor, 2,2' (5,5 dioctyl 5 H dibenzo[b,d]silole 3,7 diyl)bis(thiophene 5,2 diyl))bis(methanylylidene))bis(1 H indene 1,3(2 H) dione) (called N5) comprised of dibenzosilole and 1,3 indanedione building blocks was designed, synthesized, and fully characterized. N5 is highly soluble in various organic solvents, has high thermal stability, and has energy levels matching those of archetypal donor poly(3 hexylthiophene) Solution processable, bulk heterojunction solar cells afforded promising power conversion efficiency of 2.76 when N5 was used as a non fullerene electron acceptor along with the conventional donor polymer poly(3 hexylthiophene) As per our knowledge, the material reported herein is the first example in the literature where synchronous use of such building blocks is demonstrated in the design an efficient, non fullerene acceptor.",
"author_names": [
"Hemlata Patil",
"Akhil Gupta",
"Ben Alford",
"Di Ma",
"Steven H Priver",
"Ante Bilic",
"Prashant Sonar",
"Sheshanath V Bhosale"
],
"corpus_id": 94298986,
"doc_id": "94298986",
"n_citations": 19,
"n_key_citations": 0,
"score": 0,
"title": "Conjoint use of Dibenzosilole and Indan 1,3 dione Functionalities to Prepare an Efficient Non Fullerene Acceptor for Solution Processable Bulk Heterojunction Solar Cells",
"venue": "",
"year": 2015
},
{
"abstract": "Non fullerene acceptors have recently attracted tremendous interest because of their potential as alternatives to fullerene derivatives in bulk heterojunction organic solar cells. However, the power conversion efficiencies (PCEs) have lagged far behind those of the polymer/fullerene system, mainly because of the low fill factor (FF) and photocurrent. Here we report a novel perylene bisimide (PBI) acceptor, SdiPBI Se, in which selenium atoms were introduced into the perylene core. With a well established wide band gap polymer (PDBT T1) as the donor, a high efficiency of 8.4% with an unprecedented high FF of 70.2% is achieved for solution processed non fullerene organic solar cells. Efficient photon absorption, high and balanced charge carrier mobility, and ultrafast charge generation processes in PDBT T1:SdiPBI Se films account for the high photovoltaic performance. Our results suggest that non fullerene acceptors have enormous potential to rival or even surpass the performance of their fullerene counterparts.",
"author_names": [
"Dong Meng",
"Dan Zi Sun",
"Chengmei Zhong",
"Tao Liu",
"Bingbing Fan",
"Lijun Huo",
"Yan-ping Li",
"Wei Jiang",
"Hyosung Choi",
"Taehyo Kim",
"Jin Kyun Kim",
"Yanming Sun",
"Zhaohui Wang",
"Alan J Heeger"
],
"corpus_id": 207161566,
"doc_id": "207161566",
"n_citations": 528,
"n_key_citations": 4,
"score": 0,
"title": "High Performance Solution Processed Non Fullerene Organic Solar Cells Based on Selenophene Containing Perylene Bisimide Acceptor.",
"venue": "Journal of the American Chemical Society",
"year": 2016
}
] |
directionally-sensitive radioactive dosimeter | [
{
"abstract": "In this paper, the authors propose a personal wearable directionally sensitive radiation dosimeter using multiple semiconductor CdZnTe detectors. The proposed dosimeter not only measures the real time dose rate but also provide the direction of the radioactive source. A linear relationship between radioactive source direction and the radiation intensity measured by each detectors is established and an equation to determine the source direction is derived by the authors. The efficiency and accuracy of the proposed dosimeter is verified by simulation using Geant4 package. Results have indicated that in a measurement duration of about 7 seconds, the proposed dosimeter was able to estimate the direction of a 10mCi 137 55Cs radioactive source to within 2 degrees. Keywords Dose rate, Geant4 package, radiation detectors, radioactive source direction.",
"author_names": [
"Hai H Le",
"Paul Junor",
"Moshi Geso",
"Graeme J O'Keefe"
],
"corpus_id": 53624037,
"doc_id": "53624037",
"n_citations": 0,
"n_key_citations": 0,
"score": 1,
"title": "Directionally Sensitive Personal Wearable Radiation Dosimeter",
"venue": "",
"year": 2017
},
{
"abstract": "Imaging technology based on gamma ray sources has been extensively used in non destructive testing (NDT) to detect any possible internal defects in products without changing their shapes or functions. However, such technology has been subject to increasingly stricter regulations, and an international radiation safety management system has been recently established. Consequently, radiation source location in NDT systems has become an essential process, given that it can prevent radiation accidents. In this study, we focused on developing a monitoring system that can detect, in real time, the position of a radioactive source in the source guide tube of a projector. We fabricated a lead iodide (PbI2) dosimeter based on the particle in binder method, which has a high production yield and facilitates thickness and shape adjustment. Using a gamma ray source, we then tested the reproducibility, linearity of the dosimeter response, and the dosimeter's percentage interval distance (PID) It was found that the fabricated PbI2 dosimeter yields highly accurate, reproducible, and linear dose measurements. The PID analysis conducted to investigate the possibility of developing a monitoring system based on the proposed dosimeter indicated that the valid detection distance was approximately 11.3 cm. The results of this study are expected to contribute to the development of an easily usable radiation monitoring system capable of significantly reducing the risk of radiation accidents.",
"author_names": [
"Jin Hyok Kim",
"Moo-Jae Han",
"Ye-Ji Heo",
"Sung-Kwang Park"
],
"corpus_id": 125462513,
"doc_id": "125462513",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Characterization of a new dosimeter for the development of a position sensitive detector of radioactive sources in industrial NDT equipment",
"venue": "",
"year": 2018
},
{
"abstract": "Fields that use non destructive testing (NDT) invest significant amounts of time and resources toward building a radioactive source monitoring system, for preventing any potential radiation related accidents. However, various elements that can cause potential radiation accidents due to silicon based photodiodes are involved. Therefore, research on new materials that can effectively detect high energy gamma ray is necessary. This study focused on developing a new dosimeter material for a real time monitoring system that can detect the location of a radioactive source. It was confirmed that the fabricated HgI2 dosimeters have sufficient reproducibility and dose linearity for gamma rays. Based on these results, the HgI2 dosimeter was verified to satisfy the general requirements of NDT source monitoring systems. These monitoring systems are expected to be easily operable by workers and prevent potential radiation accidents.",
"author_names": [
"Kyo-Tae Kim",
"Joo Hee Kim",
"Moo-Jae Han",
"Soon Sung Lee",
"Ye-Ji Heo",
"Gyu-Seok Cho",
"B I Min",
"Heunglae Cho",
"Kum-Bae Kim",
"Sung-Kwang Park"
],
"corpus_id": 229015858,
"doc_id": "229015858",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Characterization of a HgI2 Dosimeter for the Monitoring System of Position Detection of Radioactive Sources in Gamma Ray Projector",
"venue": "",
"year": 2020
},
{
"abstract": "Recently, cancer has been treated using high dose rates (HDRs) which requires highly reliable treatment plans. In current clinical practice, phosphors are widely used. However, these are of limited use for real time verification of radiation during HDR brachytherapy; moreover, there is a possibility of electrical error via high energy radiation because a photodiode is used to detect visible light. Therefore, it is necessary to develop a new dosimeter that can detect gamma rays effectively. This study aimed to investigate the feasibility of a lead monoxide (PbO) based dosimeter to detect the position of a radioactive source in HDR brachytherapy. It was confirmed that the fabricated PbO dosimeter has sufficient response coincidence, reproducibility, and dose linearity for gamma rays. Based on these results, it is demonstrated that the PbO dosimeter complies with the general requirements of HDR brachytherapy monitoring systems. Thus, the PbO dosimeter is expected to be used commercially in the future.",
"author_names": [
"Kyoungwoon Kim",
"Junghyun Kim",
"Yohan Shin",
"Moo-Jae Han",
"Ji-Eun Park",
"Young Jin Heo",
"D -H Lee",
"Heunglae Cho",
"B I Min",
"Y -K Oh",
"Sung-Kwang Park"
],
"corpus_id": 155127330,
"doc_id": "155127330",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Feasibility study of a lead monoxide based dosimeter for real time radioactive source detection in HDR brachytherapy",
"venue": "Journal of Instrumentation",
"year": 2019
},
{
"abstract": "Radiation safety management is being considered very important since radioactive isotopes such as Co 60 and Ir 192 are widely used in fields such as non destructive test(NDT) In this study, the applicability of Mercury(II) Iodide(HgI2) source for tracing system was evaluated. To make sure the unit cell sensor's reliability, we evaluated the electrical properties of the sensor made with HgI2, and then position dependence of the sensor was analyzed and compared with the dose distribution from the planning system. As a result of the evaluation, high reliability of the sensor was shown through the linearity of R sq 0.990 and reproducibility of CV 0.015. In the position dependence evaluation, the maximum value was measured at the isocenter of the sensor and gradually decreased according to the distance. However, the dose distribution data from the planning system was turned out that has difference with that of the sensor up to 30% This seems to come from the difference between single point measuring based planning system and area measuring based sensor.",
"author_names": [
"Yohan Shin",
"",
"Kyo-Tae Kim",
"Heunglae Cho",
"Park Sung-Kwang"
],
"corpus_id": 200063817,
"doc_id": "200063817",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "The Study on Applicability of Semi conductive Compound for Radioactive Source Tracing Dosimeter in NDT Field",
"venue": "",
"year": 2019
},
{
"abstract": "An optical fiber sensor for monitoring low dose radiation is presented. The sensor, based on radiation sensitive scintillation material, terbium doped gadolinium oxysulphide (Gd2O2S:Tb) is embedded in a cavity of 700um diameter within a 1mm plastic optical fiber. The sensor is compared with the treatment planning system for repeatability, angular dependency, distance and accumulated radiation activity. The sensor demonstrates a high sensitivity of 152 photon counts/Gy with a temporal resolution of 0.1 seconds, with the largest repeatability error of 4.1% to 0.361mCi of Iodine 125 the radioactive source most commonly used in LDR brachytherapy for treating prostate cancer.",
"author_names": [
"Peter Woulfe",
"Frank Sullivan",
"Wern Kam",
"Sinead O'Keeffe"
],
"corpus_id": 214395271,
"doc_id": "214395271",
"n_citations": 4,
"n_key_citations": 0,
"score": 0,
"title": "Optical fiber dosimeter for real time in vivo dose monitoring during LDR brachytherapy.",
"venue": "Biomedical optics express",
"year": 2020
},
{
"abstract": "In the decommissioning of the nuclear power plant, especially, for decontamination by radioactive substances caused by 2011 Fukushima nuclear power plant accident has affected the reconstruction after the earthquake, the dose evaluation and validation of the decontamination effect is very important. In order to prepare a novel passive type dosimeter system which can applied to radiation dose monitoring and visualization of two dimensional distribution of ionizing radiation in contaminated area, we try to develop a beads type and a sheet type glass dosimeter utilizing radio photo luminescence (RPL) phenomenon in Ag+ doped phosphate glass. It is confirmed that the beads type glass dosimeter with a diameter of about 50mm exhibits an intense RPL. It is found that the sheet type glass dosimeter which is made of the beads type glasses is useful for monitoring of radiation dose in wide dose range and visualization of dose distribution, for radioactive emergency monitoring.",
"author_names": [
"Hidehito Nanto",
"K Hirasawa",
"Yoshinori Takei",
"Yuka Yanagida",
"Masanori Sugiyama",
"Yoshihiro Koguchi",
"T Yamamoto",
"T Hda"
],
"corpus_id": 25122757,
"doc_id": "25122757",
"n_citations": 1,
"n_key_citations": 0,
"score": 0,
"title": "Monitoring of radiation dose distribution utilizing RPL in glass dosimeter Its application to radioactive emergency sensing",
"venue": "2017 IEEE SENSORS",
"year": 2017
},
{
"abstract": "In this chapter, a new radiation sensitive FET (RADFET) dosimeter design (called the Dual Dielectric Gate All Around DDGAA RADFET dosimeter) to improve the radiation sensitivity performance and its analytical analysis have been proposed, investigated and expected to improve the sensitivity behavior and fabrication process for RADFET dosimeter based applications. Analytical models have been developed to predict and compare the performance of the proposed design and conventional (bulk) RADFET, where the comparison of device architectures shows that the proposed design exhibits a superior performance with respect to the conventional RADFET in term of fabrication process and sensitivity performances. The proposed design has linear radiation sensitivities of approximately (95.45\\\\upmu \\mathrm{{V/Gy} for wide irradiation dose range (from \\mathrm{{Dose}=50\\\\mathrm{{Gy} to \\mathrm{{Dose}=3000\\\\mathrm{{Gy} Our results showed that the analytical analysis is in close agreement with the 2 D numerical simulation over a wide range of devices parameters. The proposed device and the Artificial Neural Networks (ANNs) have been used to study and show the impact of the proposed dosimeter on the environment monitoring and remote sensing applications. The obtained results make the DDGAA RADFET dosimeter a promising candidate for environment monitoring applications.",
"author_names": [
"Faycal Djeffal",
"M Meguellati"
],
"corpus_id": 135698797,
"doc_id": "135698797",
"n_citations": 10,
"n_key_citations": 0,
"score": 0,
"title": "Multigate RADFET Dosimeter for Radioactive Environment Monitoring Applications",
"venue": "",
"year": 2013
},
{
"abstract": "Abstract In this paper, a radiation sensitive FET (RADFET) dosimeter design (called the Dual Dielectric Gate All Around DDGAA RADFET dosimeter) to improve the radiation sensitivity performance and its analytical analysis have been proposed for RADFET dosimeter based applications (monitoring, robotics, medical sciences, The proposed device and the Artificial Neural Networks (ANNs) have been used to study and show the impact of the proposed dosimeter on the environment monitoring and remote sensing applications. The obtained results make the DDGAA RADFET dosimeter a promising candidate for environment monitoring applications.",
"author_names": [
"M Meguellati",
"Faycal Djeffal",
"Djemai Arar",
"Fouzi Douak",
"L Khettache"
],
"corpus_id": 18378879,
"doc_id": "18378879",
"n_citations": 7,
"n_key_citations": 0,
"score": 0,
"title": "New RADFET Dosimeter Design For Radioactive Environment Monitoring Applications",
"venue": "",
"year": 2012
},
{
"abstract": "Abstract A radiophotoluminescence (RPL) monitoring scope system was constructed to evaluate radioactive cesium contamination. RPL glass sheets were constructed by bonding RPL glass beads to a backing sheet. The RPL scope was constructed using an image intensifier and a CCD camera to detect RPL from the RPL glass sheet. A UV floodlight was also prepared as an excitation light source. The UV floodlight and an image intensifier were pulse operated for high signal to noise RPL detection. In experiments, the RPL of X ray irradiated glass sheets was measured with this present system. The RPL intensity, which is calculated from the brightness of obtained images, exhibits acceptable linearity to the absorbed dose. Another experiment showed that RPL can be detected at a distance of 10 m between the RPL glass sheets and the RPL detector.",
"author_names": [
"Naoki Zushi",
"Fuminobu Sato",
"Yushi Kato",
"Takayoshi Yamamoto",
"Toshiyuki Iida"
],
"corpus_id": 101095988,
"doc_id": "101095988",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "A radioactive contamination monitoring system with a bead type radiophotoluminescence glass dosimeter",
"venue": "",
"year": 2016
}
] |
Light-emitting-diodes based on conjugated polymers | [
{
"abstract": "CONJUGATED polymers are organic semiconductors, the semiconducting behaviour being associated with the p molecular orbitals delocalized along the polymer chain. Their main advantage over non polymeric organic semiconductors is the possibility of processing the polymer to form useful and robust structures. The response of the system to electronic excitation is nonlinear the injection of an electron and a hole on the conjugated chain can lead to a self localized excited state which can then decay radiatively, suggesting the possibility of using these materials in electroluminescent devices. We demonstrate here that poly(p phenylene vinylene) prepared by way of a solution processable precursor, can be used as the active element in a large area light emitting diode. The combination of good structural properties of this polymer, its ease of fabrication, and light emission in the green yellow part of the spectrum with reasonably high efficiency, suggest that the polymer can be used for the development of large area light emitting displays.",
"author_names": [
"Jeremy H Burroughes",
"Donal D C Bradley",
"A Robinson Brown",
"R N Marks",
"K Mackay",
"Richard H Friend",
"P L Burns",
"Andrew B Holmes"
],
"corpus_id": 43158308,
"doc_id": "43158308",
"n_citations": 7621,
"n_key_citations": 18,
"score": 1,
"title": "Light emitting diodes based on conjugated polymers",
"venue": "Nature",
"year": 1990
},
{
"abstract": "Nature 347, 539 541 (1990) IN the published version of this paper the name of one of the authors was incorrectly cited as P. L. Burns rather than P. L. Burn. His address is the University Chemical Laboratory, Cambridge, rather than the University Chemistry Laboratory as stated. GUIDE TO AUTHORS Please follow these guidelines so thatyoui be handled expeditiously.",
"author_names": [
"Jeremy H Burroughes",
"Donal D C Bradley",
"A Robinson Brown",
"R N Marks",
"K Mackay",
"Richard H Friend",
"Paul L Burn",
"Andrew B Holmes"
],
"corpus_id": 4370680,
"doc_id": "4370680",
"n_citations": 1965,
"n_key_citations": 12,
"score": 0,
"title": "Light emitting diodes based on conjugated polymers",
"venue": "Nature",
"year": 1990
},
{
"abstract": "Wide range low voltage continuous color tuning is achieved in multilayer light emitting diodes based exclusively on the commonly used high efficiency electroluminescent conjugated polymers. There are three layers for red, green, and blue emission, and one extra layer for electron blocking. The color of the emitted photon depends on the position of the electron hole recombination. Due to the stronger field dependence of the electron mobility relative to the hole mobility, the recombination zone is pushed away from the cathode and concentrated in different emissive layers as the voltage increases.",
"author_names": [
"C C Huang",
"Hsin-Fei Meng",
"G K Ho",
"Chiou-Feng Chen",
"Chian-Shu Hsu",
"Jian-Ming Huang",
"Sheng-Fu Horng",
"Boyu Chen",
"L C Chen"
],
"corpus_id": 122695013,
"doc_id": "122695013",
"n_citations": 57,
"n_key_citations": 0,
"score": 0,
"title": "Color tunable multilayer light emitting diodes based on conjugated polymers",
"venue": "",
"year": 2004
},
{
"abstract": "A series of random conjugated copolymers PFCFS1 20 with 2,5 diphenyl 3,4 bis(3 fluorophenyl) silole (fluorinated TPS) chemically doped in 2,7 fluorene 2,7 carbazole main chain were successfully synthesized and characterized. Polymers PFCFS1 20 with fluorinated TPS contents from 1 to 20 possess high weight average molecular weights between 63.5 and 114.1 kg mol 1. The absorption spectra of THF solutions and films of PFCFS1 20 are very similar, showing peaks around 385 nm and optical band gaps around 2.87 eV. Almost no red shifts of the absorption peaks from a solution to a solid state film for the four copolymers indicate that their interchain interactions are extremely weak. PFCFS1 20 solutions show blue emissions with very limited intrachain excitation energy transfers. The films of PFCFS1 20 also display blue emissions with main peaks at 449 nm for PFCFS1 and 475 nm for PFCFS20, suggesting that the fluorinated TPS may comprise more twisted phenyl peripherals. Two types of electroluminescence (EL) devices with configurations of ITO/PEDOT:PSS/PFCFS/CsF/Al and ITO/PEDOT:PSS/PFCFS/TPBI/CsF/Al were investigated. It was found that PFCFS1 20 in the two types of EL devices could show blue to sky blue emissions. Among PFCFS1 20, for EL devices without TPBI layer, PFCFS5 possesses the best device performances with maximum luminous efficiency (LEmax) of 1.46 cd A 1 and maximum external quantum efficiency (EQEmax) of 0.93 The insertion of TPBI as the electron transport layer remarkably improves the EL performances. Also PFCFS5 displays the best LEmax of 4.59 cd A 1 and EQEmax of 3.21 The latter one is among the best efficiency so far reported for silole containing polymers. Our results suggest that the fluorinated TPS is an efficient chromophore for constructions of blue emissive conjugated polymers.",
"author_names": [
"Lianjie Zhang",
"Zhulin Liu",
"Xiaofei Zhang",
"Junwu Chen",
"Yong Cao"
],
"corpus_id": 94409120,
"doc_id": "94409120",
"n_citations": 5,
"n_key_citations": 0,
"score": 0,
"title": "Efficient Blue Light Emitting Diodes Based on Conjugated Polymers with Fluorinated Silole Chemically Doped in Fluorene Carbazole Main Chain",
"venue": "Journal of Inorganic and Organometallic Polymers and Materials",
"year": 2014
},
{
"abstract": "",
"author_names": [
"Paul L Burn",
"Andrew B Holmes",
"Arno Kraft",
"A Robinson Brown",
"Donal D C Bradley",
"Richard H Friend"
],
"corpus_id": 94487490,
"doc_id": "94487490",
"n_citations": 60,
"n_key_citations": 0,
"score": 0,
"title": "Light Emitting Diodes Based on Conjugated Polymers: Control of Colour and Efficiency",
"venue": "",
"year": 1992
},
{
"abstract": "",
"author_names": [
"Changyun Jiang",
"Wei Yang",
"Junbiao Peng",
"Steven Shuyong Xiao",
"Yong Cao"
],
"corpus_id": 97562167,
"doc_id": "97562167",
"n_citations": 193,
"n_key_citations": 0,
"score": 0,
"title": "High Efficiency, Saturated Red Phosphorescent Polymer Light Emitting Diodes Based on Conjugated and Non Conjugated Polymers Doped with an Ir Complex",
"venue": "",
"year": 2004
},
{
"abstract": "Abstract A series of blue light emitting conjugated polymers based on electron donating trifluoren 2 ylamine and electron deficient dibenzothiophene S,S dioxide were synthesized via typical Suzuki coupling reactions. Their thermal, photophysical and electrochemical properties were fully studied. Owing to the excellent thermal stability, film forming ability as well as the favorable energy levels of the polymers, highly efficient non doped single layer blue devices by using these polymers as an emitting layer (EML) were achieved. Among them, the device based on PSFOFN1 showed the highest maximum current efficiency (CEmax) of 1.99 cd/A. Moreover, the device presented small efficiency roll off with current efficiency (CE) of 1.97 cd/A at high brightness up to 100 cd/m2. In addition, the Commission Internationale de L'Eclairage (CIE) coordinates of all the devices are very close to the deep blue region. Our findings suggest the potential applications of the polymers in full color flat panel displays and organic lighting.",
"author_names": [
"Hua Ye",
"Baofeng Zhao",
"Dongyun Li",
"Dongcheng Chen",
"Gaozhan Xie",
"Shi-Jian Su",
"Wei Yang",
"Yong Cao"
],
"corpus_id": 92861145,
"doc_id": "92861145",
"n_citations": 3,
"n_key_citations": 0,
"score": 0,
"title": "Highly efficient non doped single layer blue organic light emitting diodes based on light emitting conjugated polymers containing trifluoren 2 ylamine and dibenzothiophene S,S dioxide",
"venue": "",
"year": 2015
},
{
"abstract": "Since the first attempt that was made to obtain direct circularly polarized (CP) light from OLEDs by Meijer et al. in 1997, considerable efforts have been devoted to the development of circularly polarized organic light emitting diodes (CP OLEDs) particularly in the recent years. Circularly polarized electroluminescence (CPEL) based on OLEDs has attracted increasing interest for its efficient ability to generate CP light directly and wide potential applications in 3D displays, optical data storage, and optical spintronics. In this review, we systematically summarize the recent progress in chiral emitter based OLEDs with CPEL properties including CPEL based on chiral conjugated polymers, CPEL based on chiral metal complexes, and CPEL based on chiral simple organic molecules, especially chiral thermally activated delayed fluorescence (TADF) molecules. We believe that this review will provide a promising perspective of chiral emitter based OLEDs with CPEL properties for a broad range of scientists in different disciplinary areas and attract a growing number of researchers to this fast growing research field.",
"author_names": [
"Da-Wei Zhang",
"Meng Li",
"Chuan-Feng Chen"
],
"corpus_id": 210946673,
"doc_id": "210946673",
"n_citations": 81,
"n_key_citations": 0,
"score": 0,
"title": "Recent advances in circularly polarized electroluminescence based on organic light emitting diodes.",
"venue": "Chemical Society reviews",
"year": 2020
},
{
"abstract": "White light emitting diodes (LEDs) were fabricated using GaN based 380 nm UV LEDs precoated with the composite of blue emitting polymer (poly[(9,9 dihexylfluorenyl 2,7 diyl) alt co (2 methoxy 5 {2 ethylhexyloxy) 1 ,4 phenylene) yellow green emitting polymer (poly[(9,9 dioctylfluorenyl 2,7 diyl) co (1,4 benzo {2,1',3} thiadiazole) and 605 nm red emitting quantum dots (QDs) CdSe cores were obtained by solvothermal route using CdO, Se precursors and ZnS shells were synthesized by using diethylzinc, and hexamethyldisilathiane precursors. The optical properties of CdSe/ZnS QDs were characterized by UV visible and photoluminescence (PL) spectra. The structural data and composition of the QDs were transmission electron microscopy (TEM) and EDX technique. The quantum yield and size of the QDs were 58.7% and about 6.7 nm, respectively. Three band white light was generated by hybridizing blue (430 nm) green (535 nm) and red (605 nm) emission. The color rendering index (CRI) of the device was extremely improved by introducing the QDs. The CIE 1931 chromaticity coordinate, color temperature, and CRI of a white LED at 20 mA were (0.379, 0.368) 3969 K, and 90, respectively.",
"author_names": [
"Hyunchul Jung",
"Wonkeun Chung",
"Chang Hun Lee",
"Sung Hyun Kim"
],
"corpus_id": 21410340,
"doc_id": "21410340",
"n_citations": 14,
"n_key_citations": 0,
"score": 0,
"title": "Fabrication of white light emitting diodes based on UV light emitting diodes with conjugated polymers (CdSe/ZnS) quantum dots as hybrid phosphors.",
"venue": "Journal of nanoscience and nanotechnology",
"year": 2012
},
{
"abstract": "Abstract We report the use of green and blue fluorene conjugated polymers doped with hole transport materials consisting of triarylamine copolymers to fabricate bright and efficient blue and green single layer light emitting diodes (LEDs) These blends show enhanced quantum and power efficiency, much higher brightness and current densities and lower turn on and operating voltages compared with undoped devices. Optimised blue emission devices exhibited a maximum brightness of 1550 cd/m 2 a maximum external electroluminescence quantum efficiency of 0.9 cd/A or 0.4% and a maximum power efficiency of 0.3 lm/W. Optimised green emission devices showed a maximum brightness of 7400 cd/m 2 a maximum external electroluminescence quantum yield of 0.9% or 2.75 cd/A and a maximum power efficiency of 0.64 lm/W at high brightness.",
"author_names": [
"Leonidas C Palilis",
"David G Lidzey",
"Michael Redecker",
"Donal D C Bradley",
"Michael Inbasekaran",
"Edmund P Woo",
"Weishi Wu"
],
"corpus_id": 95307487,
"doc_id": "95307487",
"n_citations": 25,
"n_key_citations": 0,
"score": 0,
"title": "Bright and efficient blue and green light emitting diodes based on conjugated polymer blends",
"venue": "",
"year": 2000
}
] |
A nanometre-scale mechanical electrometer | [
{
"abstract": "The mechanical detection of charge has a long history, dating back more than 200 years to Coulomb's torsion balance electrometer. The modern analogues of such instruments are semiconductor based field effect devices, the most sensitive of which are cryogenically cooled single electron transistors. But although these latter devices have extremely high charge sensitivity, they suffer from limited bandwidth and must be operated at millikelvin temperatures in order to reduce thermal noise. Here we report the fabrication and characterization of a working nanometre scale mechanical electrometer. We achieve a charge sensitivity of 0.1 e Hz 0.5, competitive with conventional semiconductor field effect transistors; moreover, thermal noise analysis indicates that the nanometre scale electrometer should ultimately reach sensitivities of the order of 10 6 e Hz 0.5, comparable with charge detection capabilities of cryogenic single electron transistors. The nanometre scale electrometer has the additional advantages of high temperature (4.2 K) operation and response over a larger bandwidth, from which a diversity of applications may result.",
"author_names": [
"Andrew N Cleland",
"Michael L Roukes"
],
"corpus_id": 4425731,
"doc_id": "4425731",
"n_citations": 422,
"n_key_citations": 4,
"score": 1,
"title": "A nanometre scale mechanical electrometer",
"venue": "Nature",
"year": 1998
},
{
"abstract": "This paper characterises the pore types and their distribution in the Vaca Muerta Formation, Neuquen Basin, Argentina. This formation is now being studied and targeted as reservoir rock, and it is therefore considered an unconventional resource play. There is significant need for a porosity description as part of the unconventional reservoir characterisation. Mineral compositions, grain assemblages, morphology, organic content and distribution, and micron to nanometre scale pore types are studied through scanning electron microscopy. Petrographic observations depict the complex response of pores to chemical and mechanical processes, where both destruction of primary porosity and generation of secondary pores are common. Compaction, cementation and infill of migrated organic matter destroy primary porosity whereas dissolution and secondary organic matter generated through maturation create secondary pores. Lamina sets with major detrital components can help identify intervals with higher interparticle and intraparticle porosity. Interparticle and intraparticle porosity are ubiquitous throughout the samples. Interparticle pores are common around rigid detrital grains, like quartz and feldspar, and within detrital clay platelets. Porosity within authigenic clay cements is included, as framework porosity and samples may contain up to a maximum of 30 wt% clay. Partial grain dissolution of coccoliths, feldspars and calcite grains resulted in available intraparticle pore space. Organopores are the least abundant pore types at this location. Organopores were described within migrated organic matter. Although the kerogen type (Type II) and the vitrinite reflectance are optimum for hydrocarbon generation (ca 0.80% Ro) in the Vaca Muerta Formation at the study area, development of organopores is not common. The Vaca Muerta Formation has experienced insufficient thermal maturation (early oil window) and has not yet reached peak oil.",
"author_names": [
"Eider Hernandez-Bilbao",
"J Rick Sarg",
"Stephen A Sonnenberg"
],
"corpus_id": 224924735,
"doc_id": "224924735",
"n_citations": 0,
"n_key_citations": 0,
"score": 0,
"title": "Micron to nanometre scale pore characterisation of the early oil window Vaca Muerta Formation, Neuquen Basin, Argentina",
"venue": "",
"year": 2020
},
{
"abstract": "To devise new strategies to treat bone disease in an ageing society, a more detailed characterisation of the process by which bone mineralises is needed. In vitro studies have suggested that carbonated mineral might be a precursor for deposition of bone apatite. Increased carbonate content in bone may also have significant implications in altering the mechanical properties, for example in diseased bone. However, information about the chemistry and coordination environment of bone mineral, and their spatial distribution within healthy and diseased tissues, is lacking. Spatially resolved analytical transmission electron microscopy is the only method available to probe this information at the length scale of the collagen fibrils in bone. In this study, scanning transmission electron microscopy combined with electron energy loss spectroscopy (STEM EELS) was used to differentiate between calcium containing biominerals (hydroxyapatite, carbonated hydroxyapatite, beta tricalcium phosphate and calcite) A carbon K edge peak at 290 eV is a direct marker of the presence of carbonate. We found that the oxygen K edge structure changed most significantly between minerals allowing discrimination between calcium phosphates and calcium carbonates. The presence of carbonate in carbonated HA (CHA) was confirmed by the formation of peak at 533 eV in the oxygen K edge. These observations were confirmed by simulations using density functional theory. Finally, we show that this method can be utilised to map carbonate from the crystallites in bone. We propose that our calibration library of EELS spectra could be extended to provide spatially resolved information about the coordination environment within bioceramic implants to stimulate the development of structural biomaterials.",
"author_names": [
"Michal M Klosowski",
"Robert J Friederichs",
"Robert Nichol",
"Nikolas Antolin",
"Raffaella Carzaniga",
"Wolfgang Windl",
"Serena M Best",
"Sandra J Shefelbine",
"David W McComb",
"Alexandra E Porter"
],
"corpus_id": 5045250,
"doc_id": "5045250",
"n_citations": 21,
"n_key_citations": 2,
"score": 0,
"title": "Probing carbonate in bone forming minerals on the nanometre scale.",
"venue": "Acta biomaterialia",
"year": 2015
},
{
"abstract": "Future 'smart' structures have the potential to revolutionize many engineering applications. One of the possible methods for creating smart structures is through the use of shape memory alloy (SMA) fibres embedded into metal matrices. Ultrasonic consolidation (UC) allows the embedding of SMAs into metal matrices while retaining the SMA's intrinsic recoverable deformation property. In this work, NiTi SMA fibres were successfully embedded into an Al 3003 (0) matrix via the UC layer manufacturing process. Initially the plastic flow of the Al matrix and the degree of fibre encapsulation were observed using optical microscopy. Then microstructural grain and sub grain size variation of the Al 3003 (0) matrix at the fibre matrix interface, and the nature of the fibre matrix bonding mechanism, were studied via the use of focused ion beam (FIB) cross sectioning, FIB imaging, scanning electron microscopy, and mechanical peel testing. The results show that the inclusion of the NiTi SMA fibres had a significant effect on the surrounding Al matrix microstructure during the UC process. Additionally, the fibre matrix bonding mechanism appeared to be mechanical entrapment with the SMA surface showing signs of fatigue from the UC embedding process.",
"author_names": [
"Ross J Friel",
"Russell A Harris"
],
"corpus_id": 53456086,
"doc_id": "53456086",
"n_citations": 29,
"n_key_citations": 2,
"score": 0,
"title": "A nanometre scale fibre to matrix interface characterization of an ultrasonically consolidated metal matrix composite",
"venue": "",
"year": 2010
},
{
"abstract": "This paper introduces a new experimental method to monitor the evolving intra particle, nanometre scale response during hydro mechanical tests on undisturbed wet clay samples using small angle X ray scattering (SAXS) The method uses a newly developed miniature plane strain one dimensional compression cell that facilitates simultaneous full field surface displacement measurements using digital image correlation and SAXS measurements. The 60 120 s acquisition times offered by SAXS at synchrotron facilities are beneficial to study time dependent mechanisms in clays. The experimental results presented indicate that, for the natural sensitive clay tested in this work, no significant structural changes occur at the intra particle scale during loading, even when large strains are measured at the macro scale. In addition, changes that are observed at this scale occur after the end of perturbation, i.e. the creation of new intra particle structures. Further information is obtained on the orientation evolution of the fabric by the comparative analysis of the individual mineral component response.",
"author_names": [
"Georgios Birmpilis",
"Stephen A Hall",
"Sebastian Lages",
"Jelke Dijkstra"
],
"corpus_id": 197564349,
"doc_id": "197564349",
"n_citations": 2,
"n_key_citations": 0,
"score": 0,
"title": "Monitoring of the nano structure response of natural clay under mechanical perturbation using small angle X ray scattering and digital image correlation",
"venue": "Acta Geotechnica",
"year": 2019
},
{
"abstract": "In the last decade, considerable research effort was directed to the deposition of multilayer films with layer thicknesses in the nanometer range (superlattice coatings) in order to increase the performance of various cutting tools and machine parts. The goal of the present work was to investigate the main microstructural, mechanical and wear resistance characteristics of a superlattice coating, consisting of alternate multilayer ZrN/TiAIN films, with various bilayer periods (5 20 nm) The coatings were deposited by the cathodic arc method on Si, plain carbon steel and high speed steel substrates to be used as wear resistance surfaces. The multilayer structures were prepared by using shutters placed in front of each cathode (Zr and Ti+Al) The characteristics of multilayer structures (elemental and phase composition, texture, Vickers microhardness, thickness, adhesion, and wear resistance) were determined by using various techniques (AES, XPS, XRD, microhardness measurements, scratch, and tribological tests) A comparison with the properties of ZrN and TiAIN single layer coatings was carried out.",
"author_names": [
"Alina Vladescu",
"Attila Kiss",
"Aurelian A Popescu",
"Mariana Braic",
"Mihai Balaceanu",
"Viorel Braic",
"Ioan Albert Tudor",
"Constantin Logofatu",
"Constantin Catalin Negrila",
"R G Rapeanu"
],
"corpus_id": 8046672,
"doc_id": "8046672",
"n_citations": 19,
"n_key_citations": 0,
"score": 0,
"title": "Influence of bilayer period on the characteristics of nanometre scale ZrN/TiAIN multilayers.",
"venue": "Journal of nanoscience and nanotechnology",
"year": 2008
},
{
"abstract": "The widely used 'silicon on insulator' (SOI) system consists of a layer of single crystalline silicon supported on a silicon dioxide substrate. When this silicon layer (the template layer) is very thin, the assumption that an effectively infinite number of atoms contributes to its physical properties no longer applies, and new electronic, mechanical and thermodynamic phenomena arise, distinct from those of bulk silicon. The development of unusual electronic properties with decreasing layer thickness is particularly important for silicon microelectronic devices, in which (001) oriented SOI is often used. Here we show using scanning tunnelling microscopy, electronic transport measurements, and theory that electronic conduction in thin SOI(001) is determined not by bulk dopants but by the interaction of surface or interface electronic energy levels with the 'bulk' band structure of the thin silicon template layer. This interaction enables high mobility carrier conduction in nanometre scale SOI; conduction in even the thinnest membranes or layers of Si(001) is therefore possible, independent of any considerations of bulk doping, provided that the proper surface or interface states are available to enable the thermal excitation of 'bulk' carriers in the silicon layer.",
"author_names": [
"Pengpeng Zhang",
"Emma Tevaarwerk",
"Byoung-Nam Park",
"Donald E Savage",
"George K Celler",
"Irena Knezevic",
"Paul G Evans",
"Mark A Eriksson",
"Max G Lagally"
],
"corpus_id": 4342773,
"doc_id": "4342773",
"n_citations": 148,
"n_key_citations": 5,
"score": 0,
"title": "Electronic transport in nanometre scale silicon on insulator membranes",
"venue": "Nature",
"year": 2006
},
{
"abstract": "The lipid bilayer component of biological membranes is a two dimensional liquid under physiological conditions. Computer simulation calculations based on statistical mechanical models predict this liquid to exhibit structure in the form of fluctuating lipid domains in the nanometre range. Indirect and direct experimental evidence for the small scale structure is provided by fluorescence energy transfer techniques and atomic force microscopy, respectively.",
"author_names": [
"Lars K Nielsen",
"A N Vishnyakov",
"Kent Jorgensen",
"Thomas Bjornholm",
"Ole G Mouritsen"
],
"corpus_id": 97873183,
"doc_id": "97873183",
"n_citations": 76,
"n_key_citations": 1,
"score": 0,
"title": "Nanometre scale structure of fluid lipid membranes",
"venue": "",
"year": 2000
},
{
"abstract": "Local oxidation of silicon surfaces by scanning probe microscopy is a very promising lithographic approach at nanometre scale. Here, we present two approaches to optimize the oxidation for nanofabrication purposes: (i) we analyse the reproducibility and kinetics of the oxidation of Si(100) surfaces when there is no tip and sample mechanical contact and (ii) we study the effect of modulating the voltage in the aspect ratio of the oxide structures grown. The finite tip sample separation has remarkable practical consequences: the same tip can be used to perform thousands of modifications without any sign of wear. In addition, the structures generated do not show any degradation over long periods (months) It is also found that the kinetics is independent of the force microscopy mode used (contact or non contact) On the other hand, the application of an AC voltage to induce the oxidation significantly modifies the aspect ratio of the structures. A detailed description of the oxidation mechanism is proposed to account for both results.",
"author_names": [
"Montserrat Calleja",
"Jose V Anguita",
"Ricardo Garcia",
"Karen Birkelund",
"Francesc Perez-Murano",
"John A Dagata"
],
"corpus_id": 51800191,
"doc_id": "51800191",
"n_citations": 53,
"n_key_citations": 0,
"score": 0,
"title": "Nanometre scale Oxidation of Silicon Surfaces by Dynamic Force Microscopy: Reproducibility, Kinetics and Nanofabrication",
"venue": "",
"year": 1999
},
{
"abstract": "Understanding the relative motion of objects in contact is essential for controlling macroscopic lubrication and adhesion, for comprehending biological macromolecular interfaces, and for developing submicrometre scale electromechanical devices, An object undergoing lateral motion while in contact with a second object can either roll or slide. The resulting energy loss and mechanical wear depend largely on which mode of motion occurs. At the macroscopic scale, rolling is preferred over sliding, and it is expected to have an equally important role in the microscopic domain. Although progress has been made in our understanding of the dynamics of sliding at the atomic level, we have no comparable insight into rolling owing to a lack of experimental data on microscopic length scales. Here we produce controlled rolling of carbon nanotubes on graphite surfaces using an atomic force microscope. We measure the accompanying energy loss and compare this with sliding. Moreover, by reproducibly rolling a nanotube to expose different faces to the substrate and to an external probe, we are able to study the object over its complete surface.",
"author_names": [
"Michael R Falvo",
"R M Taylor",
"Aron T Helser",
"V Chi",
"Frederick P Brooks",
"Sean Washburn",
"Richard Superfine"
],
"corpus_id": 4426567,
"doc_id": "4426567",
"n_citations": 413,
"n_key_citations": 8,
"score": 0,
"title": "Nanometre scale rolling and sliding of carbon nanotubes",
"venue": "Nature",
"year": 1999
}
] |
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