What is Semiconductor?
[[File:Semiconductor-1.jpg|thumb|right|300px|{{center|Semiconductor-based electronic components}}]] A '''semiconductor''' is a [[material]] that in some cases will [[Conduction|conduct]] [[electricity]] but not in others.<ref>{{cite web|url=http://whatis.techtarget.com/definition/semiconductor|title=What is semiconductor? - Definition from WhatIs.com|work=WhatIs.com|accessdate=15 May 2015}}</ref> Good [[electrical conductor]]s, like [[copper]] or [[silver]], easily allow electricity to flow through them.<ref name=Turley4>James L. Turley, ''The Essential Guide to Semiconductors'' (Upper Saddle River, NJ: Prentice Hall Professional Technical Reference, 2003), p. 4</ref> Materials that block the flow of electricity, like [[rubber]] or [[plastic]], are called [[Insulator (electricity)|insulators]].<ref name=Turley4/> Insulators are often used to protect people from [[electric shock]]. As the name [[wikt:imply|implies]], a semiconductor does not conduct as well as a conductor.<ref>{{cite web |url=https://www.st-andrews.ac.uk/~www_pa/Scots_Guide/info/comp/conduct/conduct.htm |title=Conductors and Semiconductors |author= |website= |publisher=University of St. Andrews |accessdate=31 October 2016}}</ref> [[Silicon]] is the most used semiconductor, but [[gallium arsenide]] is also used. By the addition of different atoms into the crystal lattice (grid) of the semiconductor it changes its conductivity by making [[N-type semiconductor|n-type]] and [[P-type semiconductor|p-type]] semiconductors. [[Silicon]] is the most important commercial semiconductor, though many others are used. They can be made into [[transistor]]s, which are small amplifiers. Transistors are used in computers, mobile phones, digital audio players and many other electronic devices. Like other solids, the electrons in semiconductors can have energies only within certain bands (i.e. ranges of energy levels) between the energy of the ground state, corresponding to electrons tightly bound to the [[Atomic nucleus|atomic nuclei]] of the material, and the fre