When was the first graphene production technique developed?
Graphene
The theory of graphene was first explored by Wallace in 1947 as a starting point for understanding the electronic properties of 3D graphite. The emergent massless Dirac equation was first pointed out by Semenoff, DiVincenzo and Mele. The earliest TEM images of few-layer graphite were published by Ruess and Vogt in 1948. An early, detailed study on few-layer graphite dates to 1962 when Boehm and colleagues reported producing monolayer flakes of reduced graphene oxide. Efforts to make thin films of graphite by mechanical exfoliation started in 1990, but nothing thinner than 50 to 100 layers was produced before 2004. Initial attempts to make atomically thin graphitic films employed exfoliation techniques similar to the drawing method. Multilayer samples down to 10 nm in thickness were obtained.
Flexography
In 1890, the first such patented press was built in Liverpool, England by Bibby, Baron and Sons. The water-based ink smeared easily, leading the device to be known as "Bibby's Folly". In the early 1900s, other European presses using rubber printing plates and aniline oil-based ink were developed. This led to the process being called "aniline printing". By the 1920s, most presses were made in Germany, where the process was called "gummidruck", or rubber printing. In modern-day Germany, they continue to call the process "gummidruck".
History of graphene
Commercialization of graphene proceeded rapidly once commercial scale production was demonstrated. In 2014 two North East England commercial manufacturers, Applied Graphene Materials and Thomas Swan Limited (with Trinity College, Dublin researchers), began manufacturing. In East Anglia Cambridge Nanosystems operates a graphene powder production facility. By 2017, 13 years after creation of the first laboratory graphene electronic device, an integrated graphene electronics chip was produced commercially and marketed to pharmaceutical researchers by Nanomedical Diagnostics in San Diego.
Celtic graphite pottery
Graphite wheel thrown pottery occurs at Polish sites in layers dated to La Tène B to La Tène D and to the begimning of the Early Roman Period (1st century AD).
Potential applications of graphene
A 2008 paper demonstrated a switching effect based on a reversible chemical modification of the graphene layer that gives an on–off ratio of greater than six orders of magnitude. These reversible switches could potentially be employed in nonvolatile memories. In 2008, the smallest transistor so far, one atom thick, 10 atoms wide was made of graphene. IBM announced in December 2008 that they had fabricated and characterized graphene transistors operating at GHz frequencies.
Graphene production techniques
Epitaxy refers to the deposition of a crystalline overlayer on a crystalline substrate, where there is registry between the two. In some cases epitaxial graphene layers are coupled to surfaces weakly enough (by Van der Waals forces) to retain the two dimensional electronic band structure of isolated graphene. An example of this weak coupling is epitaxial graphene on SiC and on Pt(111). On the other hand, the epitaxial graphene layer on some metals can be strongly bonded to the surface with covalent bonds. The properties of the covalently bonded graphene can differ from the ones of free-standing graphene. An example of this strong coupling is epitaxial graphene on Ru(0001). However, the coupling is strong only for the first graphene layer on Ru(0001): the second layer is more weakly coupled to the first layer and has already properties very close to the free standing graphene.
Graphene
In applications where the thickness and packing density of the graphene layer need to be carefully controlled, the Langmuir-Blodgett method has been used to produce single layer films of graphene and graphene oxide which can then be reduced to graphene. Some of the benefits of Langmuir-Blodgett deposition include accurate control over the layered architecture of the graphene, that the layer-by-layer deposition process allows assembling any combination of thin carbon layers on a substrates, and that the assembly process is performed at room temperature and produces greater throughputs while being amenable to automation and mass production.
Photography
Autochrome, the first commercially successful color process, was introduced by the Lumière brothers in 1907. Autochrome plates incorporated a mosaic color filter layer made of dyed grains of potato starch, which allowed the three color components to be recorded as adjacent microscopic image fragments. After an Autochrome plate was reversal processed to produce a positive transparency, the starch grains served to illuminate each fragment with the correct color and the tiny colored points blended together in the eye, synthesizing the color of the subject by the additive method. Autochrome plates were one of several varieties of additive color screen plates and films marketed between the 1890s and the 1950s.
History of the petroleum industry
The production of these oils and solid paraffin wax from coal formed the subject of his patent dated 17 October 1850. In 1850 Young & Meldrum and Edward William Binney entered into partnership under the title of E.W. Binney & Co. at Bathgate in West Lothian and E. Meldrum & Co. at Glasgow; their works at Bathgate were completed in 1851 and became the first truly commercial oil-works and oil refinery in the world, using oil extracted from locally mined torbanite, shale, and bituminous coal to manufacture naphtha and lubricating oils; paraffin for fuel use and solid paraffin were not sold till 1856.
Abraham Pineo Gesner, a Canadian geologist developed a process to refine a liquid fuel from coal, bitumen and oil shale. His new discovery, which he named kerosene, burned more cleanly and was less expensive than competing products, such as whale oil. In 1850, Gesner created the Kerosene Gaslight Company and began installing lighting in the streets in Halifax and other cities. By 1854, he had expanded to the United States where he created the North American Kerosene Gas Light Company at Long Island, New York. Demand grew to where his company’s capacity to produce became a problem, but the discovery of petroleum, from which kerosene could be more easily produced, solved the supply problem.
Potential applications of graphene
Graphene exhibits a pronounced response to perpendicular external electric fields, potentially forming field-effect transistors (FET). A 2004 paper documented FETs with an on-off ratio of ≈30 at room temperature. A 2006 paper announced an all-graphene planar FET with side gates. Their devices showed changes of 2% at cryogenic temperatures. The first top-gated FET (on–off ratio of <2) was demonstrated in 2007. Graphene nanoribbons may prove generally capable of replacing silicon as a semiconductor.
Graphene
As of 2014, exfoliation produced graphene with the lowest number of defects and highest electron mobility. Geim and Novoselov initially used adhesive tape to pull graphene sheets away from graphite. Achieving single layers typically requires multiple exfoliation steps. After exfoliation the flakes are deposited on a silicon wafer. Alternatively a sharp single-crystal diamond wedge cleave layers from a graphite source. Another method is reduction of graphite oxide monolayer films, e.g. by hydrazine with annealing in argon/hydrogen with an almost intact carbon framework that allows efficient removal of functional groups. Measured charge carrier mobility exceeded /Vs. Defect-free, unoxidized graphene-containing liquids can be made from graphite using mixers that produce local shear rates greater than . Burning a graphite oxide coated DVD produced a conductive graphene film (1738 siemens per meter) and specific surface area (1520 square meters per gram) that was highly resistant and malleable.
Graphene production techniques
Andre Geim and Konstantin Novoselov initially used adhesive tape to split graphite into graphene. Achieving single layers typically requires multiple exfoliation steps, each producing a slice with fewer layers, until only one remains. After exfoliation the flakes are deposited on a silicon wafer. Crystallites larger than 1 mm and visible to the naked eye can be obtained.
Chemical vapor deposition
The most popular carbon source that is used to produce graphene is methane gas. One of the less popular choices is petroleum asphalt, notable for being inexpensive but more difficult to work with.
Deji Akinwande
Akinwande collaborated with Aixtron on wafer-scale growth of graphene, characterization and integration The collaboration demonstrated scalable growth of polycrystalline graphene using chemical vapour deposition, creating the first 300 mm wafers. In 2011 he published the first textbook on Carbon Nanotube and Graphene Device Physics with Prof. Philip Wong of Stanford University. He was made a senior member of Institute of Electrical and Electronics Engineers (IEEE) in 2013. He has made several advances in two dimensional graphene electronics. In 2015 he demonstrated the first two dimensional silicene transistor. Akinwande in collaboration with Alessandro Molle's group at CNR, Italy, achieved this by evaporating silicon onto a crystal of silver, monitoring the growth in real-time using scanning tunnelling microscopy. This research breakthrough was selected as one of the top science stories of 2015 by Discover magazine. The silicene work is the most cited Nature Nanotechnology publication of similar age.
Graphene
Multiple production techniques have been developed. Isolated 2D crystals cannot be grown via chemical synthesis beyond small sizes even in principle, because the rapid growth of phonon density with increasing lateral size forces 2D crystallites to bend into the third dimension. In all cases, graphene must bond to a substrate to retain its two-dimensional shape.
Graphene chemistry
Using paper-making techniques on dispersed, oxidized and chemically processed graphite in water, monolayer flakes form a single sheet and create strong bonds. These sheets, called graphene oxide paper, have a measured tensile modulus of 32 GPa. The chemical property of graphite oxide is related to the functional groups attached to graphene sheets. These can change the polymerization pathway and similar chemical processes. Graphene oxide flakes in polymers display enhanced photo-conducting properties. Graphene is normally hydrophobic and impermeable to all gases and liquids (vacuum-tight). However, when formed into graphene oxide-based capillary membrane, both liquid water and water vapor flow through as quickly as if the membrane was not present.
Cambridge Nanosystems
The company has developed a process to produce graphene at ultra-high quality and on a larger scale than has previously been possible by using biogas waste products such as Methane.
Graphene production techniques
Another approach covered a sheet of silicon dioxide glass (the substrate) on one side with a nickel film. Graphene deposited via chemical vapor deposition formed into layers on both sides of the film, one on the exposed top side, and one on the underside, sandwiched between nickel and glass. Peeling the nickel and the top layer of graphene left an intervening layer of graphene on the glass. While the top graphene layer could be harvested from the foil as in earlier methods, the bottom layer was already in place on the glass. The quality and purity of the attached layer was not assessed.
Graphene morphology
In 2011, researchers reported making fibers using chemical vapor deposition grown graphene films. The method was scalable and controllable, delivering tunable morphology and pore structure by controlling the evaporation of solvents with suitable surface tension. Flexible all-solid-state supercapacitors based on such fibers were demonstrated in 2013.
Graphene oxide paper
Detailed studies of graphite oxide paper by V. Kohlschütter and P. Haenni date back to 1918. Studies of graphite oxide membranes were performed by Hanns-Peter Boehm, the German scientist who invented the term "graphene", in 1960. The paper titled "Graphite Oxide and its membrane properties" reported synthesis of "paper-like foils" with 0.05 mm thickness. The membranes were reported to be not permeable by gases (nitrogen and oxygen) but easily permeable by water vapors and, suggestively, by any other solvents which are able to intercalate graphite oxide. It was also reported that the membranes are not permeable by "substances of lower molecular weight".
Graphene
Dispersing graphite in a liquid medium can produce graphene by sonication followed by centrifugation. The addition of dispersants ("e.g.", graphene quantum dots) can facilitate the exfoliation process, forming aqueous graphene dispersion with high yield. Such process is straightforward, low-cost, and environmentally friendly. Sonicating graphite at the interface of two immiscible liquids, most notably heptane and water, produced macro-scale graphene films. Graphite particles can be corroded in molten salts to form a variety of carbon nanostructures including graphene. Electrochemical synthesis can exfoliate graphene. Varying a pulsed voltage controls thickness, flake area, number of defects and affects its properties. The process begins by bathing the graphite in a solvent for intercalation. The process can be tracked by monitoring the solution’s transparency with an LED and photodiode.
Bilayer graphene
Bilayer graphene is a material consisting of two layers of graphene. One of the first reports of bilayer graphene was in the seminal 2004 "Science" paper by Geim and colleagues, in which they described devices "which contained just one, two, or three atomic layers"
Two-dimensional materials
The existence of graphyne was conjectured before 1960. It has not yet been synthesized. However, graphdiyne (graphyne with diacetylene groups) was synthesized on copper substrates. Recently it has been claimed to be a competitor for graphene, due to the potential of direction-dependent Dirac cones.
History of graphene
Initial attempts to make atomically thin graphitic films employed exfoliation techniques similar to the drawing method. Multilayer samples down to 10 nm in thickness were obtained. Earlier researchers tried to isolate graphene starting with intercalated compounds, producing very thin graphitic fragments (possibly monolayers). Neither of the earlier observations was sufficient to launch the "graphene gold rush" that awaited macroscopic samples of extracted atomic planes.
Graphene production techniques
Graphene has been prepared by using a sugar (e.g. glucose, fructose, etc.) This substrate-free "bottom-up" synthesis is safer, simpler and more environmentally friendly than exfoliation. The method can control thickness, ranging from monolayer to multilayers.
Graphene production techniques
Growing graphene in an industrial resistive-heating cold wall CVD system was claimed to produce graphene 100 times faster than conventional CVD systems, cuts costs by 99 percent and produce material with enhanced electronic qualities.
Silicon carbide
When it comes to understanding how or when to use these methods of graphene production, most of them mainly produce or grow this graphene on the SiC within a growth enabling environment. It is utilized most often at rather higher temperatures (such as 1300˚C) because of SiC thermal properties. However, there have been certain procedures that have been performed and studied that could potentially yield methods that use lower temperatures to help manufacture graphene. More specifically this different approach to graphene growth has been observed to produce graphene within a temperature environment of around 750˚C. This method entails the combination of certain methods like chemical vapor deposition (CVD) and surface segregation. And when it comes to the substrate, the procedure would consist of coating a SiC substrate with thin films of a transition metal. And after the rapid heat treating of this substance, the carbon atoms would then become more abundant at the surface interface of the transition metal film which would then yield graphene. And this process was found to yield graphene layers that were more continuous throughout the substrate surface.
Graphene morphology
A film of graphene soaked in solvent to make it swell and become malleable was overlaid on an underlying substrate "former". The solvent evaporated, leaving behind a layer of graphene that had taken on the shape of the underlying structure. In this way the team was able to produce a range of relatively intricate micro-structured shapes. Features vary from 3.5 to 50 μm. Pure graphene and gold-decorated graphene were each successfully integrated with the substrate.
Phonograph cylinder
Following seven years of research and experimentation at their Volta Laboratory, Charles Sumner Tainter, Alexander Graham Bell and Chichester Bell introduced wax as the recording medium and engraving, rather than indenting, as the recording method. In 1887, their "Graphophone" system was being put to the test of practical use by official reporters of the US Congress, with commercial units later being produced by the Dictaphone Corporation. After this system was demonstrated to Edison's representatives, Edison quickly resumed work on the phonograph. He settled on a thicker all-wax cylinder, the surface of which could be repeatedly shaved down for reuse. Both the Graphophone and Edison's "Perfected Phonograph" were commercialized in 1888. Eventually, a patent-sharing agreement was signed and the wax-coated cardboard tubes were abandoned in favor of Edison's all-wax cylinders as an interchangeable standard format.
Bulletproof vest
In late 2014, researchers began studying and testing graphene as a material for use in body armor. Graphene is manufactured from carbon and is the thinnest, strongest, and most conductive material on the planet. Taking the form of hexagonally arranged atoms, its tensile strength is known to be 200 times greater than steel, but studies from Rice University have revealed it is also 10 times better than steel at dissipating energy, an ability that had previously not been thoroughly explored. To test its properties, the University of Massachusetts stacked together graphene sheets only a single carbon atom thick, creating layers ranging in thickness from 10 nanometers to 100 nanometers from 300 layers. Microscopic spherical silica "bullets" were fired at the sheets at speeds of up to 3 km (1.9 mi) per second, almost nine times the speed of sound. Upon impact, the projectiles deformed into a cone shape around the graphene before ultimately breaking through. In the three nanoseconds it held together however, the transferred energy traveled through the material at a speed of 22.2 km (13.8 mi) per second, faster than any other known material. If the impact stress can be spread out over a large enough area that the cone moves out at an appreciable velocity compared with the velocity of the projectile, stress will not be localized under where it hit. Although a wide impact hole opened up, a composite mixture of graphene and other materials could be made to create a new, revolutionary armor solution.
Graphene
Graphene has been prepared by using a sugar (e.g. glucose, sugar, fructose, etc.) This substrate-free "bottom-up" synthesis is safer, simpler and more environmentally friendly than exfoliation. The method can control thickness, ranging from monolayer to multilayers, which is known as "Tang-Lau Method".
Graphene production techniques
Heating silicon carbide (SiC) to high temperatures (>) under low pressures (~10 torr) reduces it to graphene. This process produces epitaxial graphene with dimensions dependent upon the size of the wafer. The face of the SiC used for graphene formation, silicon- or carbon-terminated, highly influences the thickness, mobility and carrier density.
Graphite
In 1896, Acheson received a patent for his method of synthesizing graphite, and in 1897 started commercial production. The Acheson Graphite Co. was formed in 1899.
Graphene production techniques
Graphene oxide can be converted to graphene using the bacteria Shewanella oneidensis
Two-dimensional materials
Graphene is a crystalline allotrope of carbon in the form of a nearly transparent (to visible light) one atom thick sheet. It is hundreds of times stronger than most steels by weight. It has the highest known thermal and electrical conductivity, displaying current densities 1,000,000 times that of copper. It was first produced in 2004.
Nuclear graphite
During this period, Fermi and Szilard purchased graphite from several manufacturers with various degrees of neutron absorption cross section: AGX graphite from National Carbon Company with 6.68 mb (millibarns) cross section, US graphite from United States Graphite Company with 6.38 mb cross section, Speer graphite from the Speer Carbon Company with 5.51 mb cross section, and when it became available, AGOT graphite from National Carbon, with 4.97 mb cross section. (See also Haag [2005].) By November 1942 National Carbon had shipped 250 tons of AGOT graphite to the University of Chicago where it became the primary source of graphite to be used in the construction of Fermi's Chicago Pile-1, the first nuclear reactor to generate a sustained chain reaction (December 2, 1942). AGOT graphite was used to build the X-10 graphite reactor in Oak Ridge TN (early 1943) and the first reactors at the Hanford Site in Washington (mid 1943), for the production of plutonium during and after World War II. The AGOT process and its later refinements became standard techniques in the manufacture of nuclear graphite.
Synthetic diamond
After the 1797 discovery that diamond was pure carbon, many attempts were made to convert various cheap forms of carbon into diamond. The earliest successes were reported by James Ballantyne Hannay in 1879 and by Ferdinand Frédéric Henri Moissan in 1893. Their method involved heating charcoal at up to 3500 °C with iron inside a carbon crucible in a furnace. Whereas Hannay used a flame-heated tube, Moissan applied his newly developed electric arc furnace, in which an electric arc was struck between carbon rods inside blocks of lime. The molten iron was then rapidly cooled by immersion in water. The contraction generated by the cooling supposedly produced the high pressure required to transform graphite into diamond. Moissan published his work in a series of articles in the 1890s.
Roger Bacon (physicist)
Roger Bacon (April 16, 1926 – January 26, 2007) was a physicist at the Parma Technical Center of National Carbon Company in suburban Cleveland, Ohio, where he invented graphite fibers in 1958.
History of graphene
Single layers of graphite were observed by TEM within bulk materials, in particular inside soot obtained by chemical exfoliation. Efforts to make thin films of graphite by mechanical exfoliation started in 1990, but nothing thinner than 50 to 100 layers was produced before 2004.
Synthesis of carbon nanotubes
Nanotubes were observed in 1991 in the carbon soot of graphite electrodes during an arc discharge, by using a current of 100 amps, that was intended to produce fullerenes. However the first macroscopic production of carbon nanotubes was made in 1992 by two researchers at NEC's Fundamental Research Laboratory. The method used was the same as in 1991. During this process, the carbon contained in the negative electrode sublimates because of the high-discharge temperatures.
Synthetic diamond
Numerous claims of diamond synthesis were documented between 1879 and 1928; most of those attempts were carefully analyzed but none were confirmed. In the 1940s, systematic research began in the United States, Sweden and the Soviet Union to grow diamonds using CVD and HPHT processes. The first reproducible synthesis was reported around 1955. Those two processes still dominate the production of synthetic diamond. A third method, known as detonation synthesis, entered the diamond market in the late 1990s. In this process, nanometer-sized diamond grains are created in a detonation of carbon-containing explosives. A fourth method, treating graphite with high-power ultrasound, has been demonstrated in the laboratory, but currently has no commercial application.
Potential applications of graphene
In February 2010, researchers announced graphene transistors with an on-off rate of 100 gigahertz, far exceeding the rates of prior attempts, and exceeding the speed of silicon transistors with an equal gate length. The devices were made with conventional silicon-manufacturing equipment. According to a January 2010 report, graphene was epitaxially grown on SiC in a quantity and with quality suitable for mass production of integrated circuits. At high temperatures, the quantum Hall effect could be measured in these samples. IBM built 'processors' using 100 GHz transistors on graphene sheets.
Graphene spray gun
Upon departing the spray gun, the graphene flake’s tendency to aggregate is reduced due to its quick evaporation and dispersion. Much to the researchers’ surprise, this spray method produces flakes that contain substantially less defects that would commonly occur. Common graphene defects including holes and lumps in the layer, and the Stone-Wales defect were absent upon surface impact. The large amount of kinetic energy delivered by the supersonic nozzle creates the healing of these defects, as the graphene flakes stretches upon impact. The carbon atoms within the graphene rearrange to create seamlessly perfect hexagonal lattice structures. The result of these perfect hexagon structures is the creation of a smooth, even layer of graphene. This is a large contrast to the applications of graphene onto large-scale substrates prior to the creation of the graphene spray gun. The graphene layers would commonly contain defecting clumps and spaces, which troubled scientists ever since the discovery of graphene. The graphene spray gun is also regarded as inexpensive when compared to the other methods of large-scale graphene applications. One main factor for its inexpensiveness is that the graphene layers require no post-processing treatment, which was common in the other methods. The other factor is that the spray gun is remarkably simple in both its production and utilization.
Graphene Research Centre
NUS established the GRC in 2010, under the leadership of Prof. Antonio H. Castro Neto, with a start-up fund from NUS of S$40 Million, 1,000 m2 of laboratory space, and a state-of-the-art clean room facility of 800 m2. Speaking of commercial application today scientists are using graphene for making synthetic blood and developing non-invasive treatments for cancer. Graphene would soon replace silicon in your computer chips thus resulting in a much faster, unbreakable tablets, phone and others; GRC is also participating on a S$50 Million CREATE grant from NRF, together with University of California, Berkeley and Nanyang Technological University, for the study of new photovoltaic systems based on two-dimensional crystals. In June 2012, the GRC announced the opening of a S$15 Million micro and nano fabrication facility to produce graphene products.
Graphene production techniques
As of 2014 exfoliation produced graphene with the lowest number of defects and highest electron mobility.
Graphene morphology
In 2013, a three-dimensional honeycomb of hexagonally arranged carbon was termed 3D graphene. Self-supporting 3D graphene was produced that year. Researchers at Stony Brook University have reported a novel radical-initiated crosslinking method to fabricate porous 3D free-standing architectures of graphene and carbon nanotubes using nanomaterials as building blocks without any polymer matrix as support. 3D structures can be fabricated by using either CVD or solution-based methods. A 2016 review summarized the techniques for fabrication of 3D graphene and other related two-dimensional materials. These 3D graphene (all-carbon) scaffolds/foams have potential applications in fields such as energy storage, filtration, thermal management and biomedical devices and implants.
Graphene Research Centre
The Graphene Research Centre (GRC), at the National University of Singapore (NUS), is the first centre in Asia dedicated to graphene research. The Centre was established under the scientific advice of two Nobel Laureates in physics – Prof Andre Geim and Prof Konstantin Novoselov - who won the 2010 Nobel Prize in Physics for their discovery of graphene. It was created for the conception, characterization, theoretical modeling, and development of transformative technologies based on two-dimensional crystals, such as graphene.
Potential applications of graphene
In 2015, researchers developed a prototype cell that used semitransparent perovskite with graphene electrodes. The design allowed light to be absorbed from both sides. It offered efficiency of around 12 percent with estimated production costs of less than $0.06/watt. The graphene was coated with PEDOT:PSS conductive polymer (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate). Multilayering graphene via CVD created transparent electrodes reducing sheet resistance. Performance was further improved by increasing contact between the top electrodes and the hole transport layer.
Graphene
One of the first patents pertaining to the production of graphene was filed in October 2002 and granted in 2006. Two years later, in 2004 Geim and Novoselov extracted single-atom-thick crystallites from bulk graphite and transferred them onto thin silicon dioxide () on a silicon wafer, which electrically isolated the graphene. The cleavage technique led directly to the first observation of the anomalous quantum Hall effect in graphene, which provided direct evidence of graphene's theoretically predicted Berry's phase of massless Dirac fermions. The effect was reported by Geim's group and by Kim and Zhang, whose papers appeared in "Nature" in 2005. Geim and Novoselov received awards for their pioneering research on graphene, notably the 2010 Nobel Prize in Physics.
Graphene production techniques
A normal silicon wafer coated with a layer of germanium (Ge) dipped in dilute hydrofluoric acid strips the naturally forming germanium oxide groups, creating hydrogen-terminated germanium. Chemical vapor deposition deposits a layer of graphene on top. The graphene can be peeled from the wafer using a dry process and is then ready for use. The wafer can be reused. The graphene is wrinkle-free, high quality and low in defects.
Two-dimensional materials
Some 700 2D materials have been predicted to be stable, although many remain to be synthesized. The global market for 2D materials is expected to reach US$390 million by 2025, mostly for graphene in the semiconductor, electronics, battery energy and composite materials markets.
The first 2D material, graphene, a single layer of graphite, was isolated in 2004. Thereafter many other 2D materials were identified.
History of graphene
One of the first patents pertaining to the production of graphene was filed in October 2002 and granted in 2006. It detailed one of the first large scale graphene production processes. Two years later, in 2004 Geim and Novoselov extracted single-atom-thick crystallites from bulk graphite. They pulled graphene layers from graphite and transferred them onto thin silicon dioxide () on a silicon wafer in a process called either micromechanical cleavage or the Scotch tape technique. The electrically isolated the graphene and weakly interacted with it, providing nearly charge-neutral graphene layers. The silicon beneath the could be used as a "back gate" electrode to vary the charge density in the graphene over a wide range. , filed in 2002, describes how to process expanded graphite to achieve a graphite thickness of one hundred-thousandth of an inch (0.25 nm). The key to success was high-throughput visual recognition of graphene on a properly chosen substrate that provides a small but noticeable optical contrast.
History of graphene
The theory of graphene was first explored by P. R. Wallace in 1947 as a starting point for understanding the electronic properties of 3D graphite. The emergent massless Dirac equation was first pointed out by Gordon W. Semenoff, David DiVincenzo and Eugene J. Mele. Semenoff emphasized the occurrence in a magnetic field of an electronic Landau level precisely at the Dirac point. This level is responsible for the anomalous integer quantum Hall effect.
Graphene production techniques
Sonicating graphite at the interface of two immiscible liquids, most notably heptane and water, produced macro-scale graphene films. The graphene sheets are adsorbed to the high energy interface between the heptane and the water, where they are kept from restacking. The graphene remained at the interface even when exposed to force in excess of 300,000 g. The solvents may then be evaporated. The sheets are up to ~95% transparent and conductive.
Potential applications of graphene
In 2010, researchers first reported creating a graphene-silicon heterojunction solar cell, where graphene served as a transparent electrode and introduced a built-in electric field near the interface between the graphene and n-type silicon to help collect charge carriers. In 2012 researchers reported efficiency of 8.6% for a prototype consisting of a silicon wafer coated with trifluoromethanesulfonyl-amide (TFSA) doped graphene. Doping increased efficiency to 9.6% in 2013. In 2015 researchers reported efficiency of 15.6% by choosing the optimal oxide thickness on the silicon. This combination of carbon materials with traditional silicon semiconductors to fabricate solar cells has been a promising field of carbon science.
Hong Byung-hee
Hong is also the founder of GSI pioneered the large-scale synthesis of graphene by chemical vapor deposition (CVD), which triggered chemical research toward the practical application of graphene. His first report on CVD synthesis of graphene ("Nature" 2009) has recorded the world highest citations in chemistry among the papers published since 2009 (roughly 5000 times). One year later, he developed the synthesis of ultra-large graphene based on roll-to-roll methods and its application to flexible touch screens ("Nature Nanotechnology". 2010), which is believed to be the first demonstration of application of graphene materials in practical electronic devices. For this contribution, he was invited to give a talk in the Nobel Symposium on Graphene (2010). He made more than 90 patent applications on graphene synthesis and applications, which corresponds to the world 2nd graphene-related inventor. Hong's research has been highlighted by Bloomberg, Businessweek, BBC, CNBC, New York Times, Financial Times, Russia Today, MIT Technology Review, C&EN News (cover story), Physics Today, and Physics World. He is now acting as Scientific Advisory Committee member of €1 billion Graphene Flagship project together with 4 Nobel Laureates and as Scientific Advisory Member of Cambridge Graphene Center, UK. He is currently an Advisory Member for CTO of LG Electronics. He served as a member of R&D Strategy and Planning Committee for Korean National Graphene Commercialization Project.
Graphene morphology
An aerogel made of graphene layers separated by carbon nanotubes was measured at 0.16 milligrams per cubic centimeter. A solution of graphene and carbon nanotubes in a mold is freeze dried to dehydrate the solution, leaving the aerogel. The material has superior elasticity and absorption. It can recover completely after more than 90% compression, and absorb up to 900 times its weight in oil, at a rate of 68.8 grams per second.
Graphene
Several techniques can prepare nanostructured graphene, e.g., graphene quantum dots (GQDs); these techniques mainly include electron beam lithography, chemical synthesis, electrochemical preparation, graphene oxide (GO) reduction, C60 catalytic transformation, the microwave assisted hydrothermal method (MAH), the Soft-Template method, the hydrothermal method, and the ultrasonic exfoliation method.
Graphene spray gun
A graphene spray gun is a kinetic spray system that deposits, through supersonic acceleration, a one atom thick sheet of pure carbon named graphene by means of a de Laval nozzle, a pinched tube with an hourglass type shape. The system deposits graphene flakes and a hexagonal graphene lattice is created upon impact of the desired surface. The graphene spray gun would be utilized onto large-scale applications such as circuits, radio transmitters, and optical electronics due to the grapehene’s transparency and its remarkable conductivity of electricity. The supersonic spray system was first developed in May 2014 by University of Illinois professor Alexander Yarin, and Korea University professor Sam Yoon. Yarin went to Yoon when he learned about his work regarding kinetic spray deposition systems. Yarin believed that graphene could be applied to the system in order to create a layer of the material. After conducting experiments with the newly created system, they concluded that the graphene spray system was a success. The spray gun is still in its early stages of development, but is considered by many scientists and researchers to be the solution of various predicaments that occur when applying graphene onto large-scale products. The most common problem that would transpire within the other methods is that the layer would be uneven and coated by aggregations. The energy delivered by the supersonic spraying stretches the graphene evenly upon impact, and is the main reason for the spray system’s lack of defects that are common within other graphene deposition methods.
Uley graphite project
Graphite was discovered in the area of the Uley project in the early 1800s and it was mined intermittently from the 1920s until 1993, when it was placed on care and maintenance. When in production, the open cut mine was capable of producing up to 14,000 tonnes of graphite concentrate annually.
History of graphene
The structure of graphite was identified in 1916 by the related method of powder diffraction. It was studied in detail by Kohlschütter and Haenni in 1918, who described the properties of graphite oxide paper. Its structure was determined from single-crystal diffraction in 1924.
Graphene
In 2017, freestanding graphene gyroids with 35 nm and 60 nm unit cells were fabricated via controlled direct chemical vapor deposition. They represent the smallest free standing periodic graphene 3D structures yet produced with a pore size of tens of nm. A graphene gyroid has five percent of the density of steel, yet is ten times as strong with an enormous surface area to volume ratio. An aerogel made of graphene layers separated by carbon nanotubes was measured at 0.16 milligrams per cubic centimeter. The material has superior elasticity and absorption: it can recover completely after more than 90% compression, and absorb up to 900 times its weight in oil, at a rate of 68.8 grams per second.
Graphene production techniques
In 2014 a laser-based single-step, scalable approach to graphene production was announced. The technique produced and patterned porous three-dimensional graphene film networks from commercial polymer films. The system used a CO2 infrared laser. The sp-carbon atoms were photothermally converted to sp-carbon atoms by pulsed laser irradiation. The result exhibits high electrical conductivity. The material can produce interdigitated electrodes for in-plane microsupercapacitors with specific capacitances of >4 mF cm and power densities of ~9 mW cm. Laser-induced production appeared to allow roll-to-roll manufacturing processes and provides a route to electronic and energy storage devices.
History of graphene
The term "graphene" was introduced in 1986 by chemists Hanns-Peter Boehm, Ralph Setton and Eberhard Stumpp. It is a combination of the word "graphite" and the suffix "-ene", referring to polycyclic aromatic hydrocarbons.
Speed Graphic
The Speed Graphic is a press camera produced by Graflex in Rochester, New York. Although the first Speed Graphic cameras were produced in 1912, production of later versions continued until 1973; with the most significant improvements occurring in 1947 with the introduction of the Pacemaker Speed Graphic (and Pacemaker Crown Graphic, which is lighter but lacks the focal plane shutter). It was standard equipment for many American press photographers until the mid-1960s.
Walter de Heer
His nanotube work led to consideration of the properties of "opened" carbon nanotubes and the development of graphene-based electronics, starting in 2001. Anticipating that patterned graphene structures would behave like interconnected carbon nanotubes, he proposed several avenues of graphene preparation, including exfoliation of graphite flakes to oxidized silicon wafers and epitaxial growth on silicon carbide. The latter was deemed most promising for large-scale integrated electronics, and was funded by Intel Corporation in 2003. In 2004, the group was awarded additional funding from the National Science Foundation for the pursuit of graphene science. The first paper, "Two dimensional electron gas properties of ultrathin epitaxial graphite", was presented in March 2004 at a meeting of the American Physical Society and published in December under the title, "Ultrathin epitaxial graphite: Two dimensional electron gas properties and a route towards graphene based electronics". This paper, based primarily on data documented in 2003, describes the first electrical measurements of epitaxial graphene, reports fabrication of the first graphene transistor, and outlines the desirable properties of graphene for use in graphene-based electronics. De Heer and coworkers Claire Berger and Phillip First hold the first patent on graphene-based electronics, provisionally filed in June 2003. The approach championed by de Heer has the advantage of producing graphene directly on a high-quality electronic material (silicon carbide) and does not require isolation or transfer to any other substrate.
Shaft (golf)
"Graphite" shafts began to emerge in the late twentieth century. The graphite shaft was invented by Frank Thomas in 1969 while working as Chief Design Engineer for Shakespeare Sporting Goods, in collaboration with Union Carbide. The original graphite shafts manufactured by Shakespeare Sporting Goods were filament wound, had extremely consistent properties and were extremely expensive. Subsequent, less expensive flagwrapped versions of the graphite shaft introduced by other manufacturers several years later had inconsistent properties and as a result professionals and skilled amateurs were initially skeptical of the new technology when compared to steel; however, advances in technology, developed by Bruce Williams, an engineer working with an Ohio-based composites company, eventually changed this perception.
History of printing
The first truly successful commercial method was patented by Frederic Ives of Philadelphia in 1881. But although he found a way of breaking up the image into dots of varying sizes he did not make use of a screen. In 1882 the German George Meisenbach patented a halftone process in England. His invention was based on the previous ideas of Berchtold and Swan. He used single lined screens which were turned during exposure to produce cross-lined effects. He was the first to achieve any commercial success with relief halftones.
Cumene process
The cumene process (cumene-phenol process, Hock process) is an industrial process for synthesizing phenol and acetone from benzene and propylene. The term stems from cumene (isopropyl benzene), the intermediate material during the process. It was invented by Heinrich Hock in 1944 and independently by R. Ūdris and P. Sergeyev in 1942 (USSR).
Potential applications of graphene
In 2012 Vorbeck Materials started shipping the Siren anti-theft packaging device, which uses their graphene-based Vor-Ink circuitry to replace the metal antenna and external wiring to an RFID chip. This was the world's first commercially available product based on graphene.
Aerographene
Aerographene was discovered at Zhejiang University by a team of scientists led by Gao Chao. He and his team had already successfully created macroscopic materials made out of graphene. These materials were one-dimensional and two-dimensional. However, when synthesizing aerographene, the scientists instead created a three-dimensional structure. The synthesis was accomplished by the freeze-drying of carbon nanotube solutions and large amounts of graphene oxide. Residual oxygen was then removed chemically.
Graphene production techniques
Graphene can be grown on ruthenium(0001) surface with CVD, temperature programmed growth (TPG) or segregation. In CVD, a hot ruthenium surface is exposed for some carbon containing molecule like methane or ethene. This results in graphene formation. It has been observed that the graphene can grow only “downhill” of the ruthenium surface steps, not uphill. 
Graphene bonds strongly with covalent bonds to the surface and has only 1.45 Å separation to the surface. This affects the electronic structure of the graphene layer, and the layer behaves differently than a free-standing graphene layer. However, the CVD graphene growth on ruthenium is not totally self-terminating and multilayer graphene formation is possible. The second and higher layers cannot bond to the existing graphene layers as strongly as the first layer bonds to the metal surface, which results in higher 3 Å separation between the graphene layers. The second layer thus has much weaker interaction with the substrate and has very similar electronic properties as free-standing graphene.
Due to the strong bonding of graphene on the ruthenium surface, only R0 orientation is observed for graphene layer. Although, different studies have shown different lengths for the moiré repeat distance, varying around Graphene(11 x 11) and Ru(10 x 10). The moiré pattern also causes strong corrugation for the graphene layer, peak height being as much as 1.5 Å.
Graphene production techniques
In this method, a sharp single-crystal diamond wedge penetrates onto the graphite source to exfoliate layers. This method uses highly ordered pyrolytic graphite (HOPG) as the starting material. The experiments were supported by molecular dynamic simulations.
Graphene
"Graphene" is a combination of "graphite" and the suffix -ene, named by Hanns-Peter Boehm and colleagues, who produced and observed single-layer carbon foils in 1962.
Graphene production techniques
Graphene is commonly deposited on iridium(111) by CVD but also with temperature programmed growth (TPG) is possible. In CVD, a hot iridium surface is exposed to ethylene. Ethylene decomposes on the surface due to pyrolysis, and the formed carbon adsorbs to the surface forming a graphene monolayer. Thus, only a monolayer growth is possible. The formed graphene layer is weakly bounded to the iridium substrate and is located about 3.3 Å above the surface. The graphene layer and the Ir(111) substrate also forms a moiré pattern with period around 25 Å, depending on the orientation of the graphene on Ir(111). There are many different possibilities for the graphene layer orientation, the most common ones being R0 and R30. The graphene layer has also corrugation due to the moiré pattern, with height varying from 0.04 Å to 0.3 Å. Due to the long-range order of these ripples, minigaps in the electronic band-structure (Dirac cone) become visible.
GrafTech
In 1914, the company introduced the first 12-inch diameter graphite electrodes.
Potential applications of graphene
Large-area, continuous, transparent and highly conducting few-layered graphene films were produced by chemical vapor deposition and used as anodes for application in photovoltaic devices. A power conversion efficiency (PCE) up to 1.71% was demonstrated, which is 55.2% of the PCE of a control device based on indium tin oxide.
History of graphene
Starting in the 1970s single layers of graphite were grown epitaxially on top of other materials. This "epitaxial graphene" consists of a single-atom-thick hexagonal lattice of sp-bonded carbon atoms, as in free-standing graphene. However, significant charge transfers from the substrate to the epitaxial graphene, and in some cases, the d-orbitals of the substrate atoms hybridize with the π orbitals of graphene, which significantly alters the electronic structure of epitaxial graphene.
Graphite
In 1893, Charles Street of Le Carbone discovered a process for making artificial graphite. Another process to make synthetic graphite was invented accidentally by Edward Goodrich Acheson (1856–1931). In the mid-1890s, Acheson discovered that overheating carborundum (silicon carbide or SiC) produced almost pure graphite. While studying the effects of high temperature on carborundum, he had found that silicon vaporizes at about 4,150 °C (7,500 °F), leaving the carbon behind in graphitic carbon. This graphite was another major discovery for him, and it became extremely valuable and helpful as a lubricant.
Cambridge Nanosystems
Cambridge Nanosystems specialises in production of graphene.
Graphene production techniques
Producing graphene via intercalation splits graphite into single layer graphene by inserting guest molecules/ions between the graphite layers. Graphite was first intercalated in 1841 using a strong oxidizing or reducing agent that damaged the material's desirable properties. Kovtyukhova developed a widely used oxidative intercalation method in 1999. In 2014, she was able to achieve intercalation using non-oxidizing Brønsted acids (phosphoric, sulfuric, dichloroacetic and alkylsulfonic acids), but without oxidizing agents. The new method has yet to achieve output sufficient for commercialization.
Graphene production techniques
Electrochemical synthesis can exfoliate graphene. Varying a pulsed voltage controls thickness, flake area, number of defects and affects its properties. The process begins by bathing the graphite in a solvent for intercalation. The process can be tracked by monitoring the solution’s transparency with an LED and photodiode.
Graphene
Scientists theorized about graphene for years. It had been produced unintentionally in small quantities for centuries through the use of pencils and other similar graphite applications. It was observed originally in electron microscopes in 1962, but it was studied only while supported on metal surfaces. The material was later rediscovered, isolated, and characterized in 2004 by Andre Geim and Konstantin Novoselov at the University of Manchester. Research was informed by existing theoretical descriptions of its composition, structure, and properties. This work resulted in the two winning the Nobel Prize in Physics in 2010 "for groundbreaking experiments regarding the two-dimensional material graphene."
Potential applications of graphene
When the Fermi level of graphene is tuned, its optical absorption can be changed. In 2011, researchers reported the first graphene-based optical modulator. Operating at without a temperature controller, this modulator has a broad bandwidth (from 1.3 to 1.6 μm) and small footprint (~).
Phosphorene
In the 1960s black phosphorus, a layered semiconducting allotrope of phosphorus, was synthesized, which exhibited high carrier mobility. In 2014, several groups introduced single-layer phosphorene, a monolayer of black phosphorus. It attracted renewed attention because of its potential in optoelectronics and electronics due to its band gap, which can be tuned via modifying its thickness, anisotropic photoelectronic properties and high carrier mobility. Phosphorene was initially prepared using mechanical cleavage, a commonly used technique in graphene production that is difficult to scale up. Liquid exfoliation is a promising method for scalable phosphorene production.
Graphene production techniques
In scanning tunneling microscopy (STM), a sharp tip scans the surface of a sample in a regime of such tip-sample distances that electrons can quantum tunneling from the tip to the sample surface or vice versa. STM can be performed in a constant current or a constant height mode. The low temperature STM measurements provide thermal stability, which is a requirement for high resolution imaging and spectroscopic analysis. The first atomically resolved images of graphene grown on a platinum substrate were obtained using STM in the 1990s.
Graphite oxide
In 2016 engineers developed graphene-based films that can filter dirty/salty water powered by the sun. Bacteria were used to produce a material consisting of two nanocellulose layers. The lower layer contains pristine cellulose, while the top layer contains cellulose and graphene oxide, which absorbs sunlight and produces heat. The system draws water from below into the material. The water diffuses into the higher layer, where it evaporates and leaves behind any contaminants. The evaporate condenses on top, where it can captured. The film is produced by repeatedly adding a fluid coating that hardens. Bacteria produce nanocellulose fibers with interspersed graphene oxide flakes. The film is light and easily manufactured at scale.
Albumen print
The albumen print, also called albumen silver print, was published in January 1847 by Louis Désiré Blanquart-Evrard, and was the first commercially exploitable method of producing a photographic print on a paper base from a negative. It used the albumen found in egg whites to bind the photographic chemicals to the paper and became the dominant form of photographic positives from 1855 to the start of the 20th century, with a peak in the 1860-90 period. During the mid-19th century, the carte de visite became one of the more popular uses of the albumen method. In the 19th century, E. & H. T. Anthony & Company were the largest makers and distributors of the Albumen photographic prints and paper in the United States.Because the image emerges as a direct result of exposure to light, without the aid of a developing solution, an albumen print may be said to be a "printed" rather than a developed photograph.
Graphene production techniques
Gram-quantities were produced by the reduction of ethanol by sodium metal, followed by pyrolysis of the ethoxide product and washing with water to remove sodium salts.
Epitaxial graphene growth on silicon carbide
The thermal decomposition of bulk SiC was first reported in 1965 by Badami. He annealed the SiC in vacuum to around 2180 °C for an hour to obtain a graphite lattice. In 1975, Bommel et al. then achieved to form monolayer graphite on the C-face as well as the Si-face of hexagonal SiC. The experiment was carried out under UHV with a temperature of 800 °C and hints for a graphene structure could be found in LEED patterns and the change in the carbon Auger peak from a carbided character to a graphite character.
New insights in the electronic and physical properties of graphene like the Dirac nature of the charge carriers, fractional quantum Hall effect or the observation of the 2D electron gas behaviour were first measured on multilayer graphene from de Heer et al. at the Georgia Institute of Technology in 2004.
Still, the Nobel Prize in Physics ″for groundbreaking experiments regarding the two-dimensional material graphene″ in 2010 was awarded to Andre Geim and Konstantin Novoselov. An official online document of the Royal Swedish Academy of Sciences about this awarding got under fire. Walter de Heer mentions several objections about the work of Geim and Novoselov who apparently have measured on many-layer graphene, also called graphite, which has different electronic and mechanical properties.
Emtsev et al. improved the whole procedure in 2009 by annealing the SiC-samples at high temperatures over 1650 °C in an argon environment to obtain morphologically superior graphene.
Graphene production techniques
Tin has been recently used for synthesis of graphene at 250°C. Low-temperature as well as the transfer free graphene growth on substrates is the major concern of graphene research for its practical applications. The transfer free graphene growth on SiO2 covered Si (SiO2/Si) substrate at 250 °C based on a solid-liquid-solid reaction has been achieved by tin.
Potential applications of graphene
In 2013 researchers created transistors printed on flexible plastic that operate at 25 gigahertz, sufficient for communications circuits and that can be fabricated at scale. The researchers first fabricated non-graphene-containing structures—the electrodes and gates—on plastic sheets. Separately, they grew large graphene sheets on metal, then peeled it and edtransfer it to the plastic. Finally, they topped the sheet with a waterproof layer. The devices work after being soaked in water, and are flexible enough to be folded.
Bilayer graphene
Bilayer graphene can be made by exfoliation from graphite or by chemical vapor deposition (CVD). In 2016, Rodney S. Ruoff and colleagues showed that large single-crystal bilayer graphene could be produced by oxygen-activated chemical vapour deposition. Later in the same year a Korean group reported the synthesis of wafer-scale single-crystal AB-stacked bilayer graphene
Andre Geim
Geim's achievements include the discovery of a simple method for isolating single atomic layers of graphite, known as graphene, in collaboration with researchers at the University of Manchester and IMT. The team published their findings in October 2004 in "Science".
Graphene production techniques
Transmission electron microscopy (TEM) uses electrons to generate high-resolution images as using electrons allows to overcome limitations of visible light wavelengths. TEM on graphene should be done with electron energy less than 80 keV to induce a smaller amount of defects, because this energy is the threshold electron energy for damaging a single-wall carbon nano-tube. There are some other difficulties in the study of graphene by TEM, e.g., in a plane-view geometry (top-view graphene) the substrate causes strong electron scattering, and a thick substrate makes it impossible to detect the graphene layer. For a cross-section view, detecting a monolayer graphene is a difficult task as it needs simulation of the TEM images.
Epitaxial graphene growth on silicon carbide
Epitaxial graphene growth on silicon carbide (SiC) by thermal decomposition is a methods to produce large-scale few-layer graphene (FLG).
Graphene is one of the most promising nanomaterials for the future because of its various characteristics, like strong stiffness and high electric and thermal conductivitiy.
Still, reproducible production of Graphene is difficult, thus lots of different techniques have been developed.
The main advantage of epitaxial graphene growth on silicon carbide over other techniques is to obtain graphene layers directly on a semiconducting or semi-insulating substrate which is commercially available.
Graphene production techniques
Graphene can be created by cutting open carbon nanotubes. In one such method multi-walled carbon nanotubes are cut open in solution by action of potassium permanganate and sulfuric acid. In another method graphene nanoribbons were produced by plasma etching of nanotubes partly embedded in a polymer film.
Graphene production techniques
Cold wall CVD technique can be used to study the underlying surface science involved in graphene nucleation and growth as it allows unprecedented control of process parameters like gas flow rates, temperature and pressure as demonstrated in a recent study. The study was carried out in a home-built vertical cold wall system utilizing resistive heating by passing direct current through the substrate. It provided conclusive insight into a typical surface-mediated nucleation and growth mechanism involved in two-dimensional materials grown using catalytic CVD under conditions sought out in the semiconductor industry.
Nuclear graphite
As a result of this meeting, over the next two years, MacPherson and Hamister developed thermal and gas extraction purification techniques at National Carbon for the production of boron-free graphite. The resulting product was designated AGOT Graphite ("Atcheson Graphite Ordinary Temperature") by National Carbon, and it was "the first true nuclear grade graphite".
Graphene oxide paper
Graphene oxide paper or graphite oxide paper is a material fabricated from graphite oxide. Micrometer thick films of graphene oxide paper are also named as graphite oxide membranes (in the 1960s) or (more recently) graphene oxide membranes. The membranes are typically obtained by slow evaporation of graphene oxide solution or by the filtration method.
Two-dimensional materials
Andre Geim and Konstantin Novoselov won the 2010 Nobel Prize in Physics "for groundbreaking experiments regarding the two-dimensional material graphene". They first produced it by lifting graphene flakes from bulk graphite with adhesive tape and then transferring them onto a silicon wafer.