Editing Semiconductor (section)

== Early history of semiconductors ==
{{See also|Semiconductor device#History of semiconductor device development|Timeline of electrical and electronic engineering}}

The history of the understanding of semiconductors begins with experiments on the electrical properties of materials. The properties of the time-temperature coefficient of resistance, rectification, and light-sensitivity were observed starting in the early 19th century.

[[File:Ferdinand Braun.jpg|thumb|218x218px|[[Karl Ferdinand Braun]] developed the [[crystal detector]], the first [[semiconductor device]], in 1874.]]

[[Thomas Johann Seebeck]] was the first to notice that semiconductors exhibit special feature such that experiment concerning an [[thermoelectric effect#Seebeck effect|Seebeck effect]] emerged with much stronger result when applying semiconductors, in 1821.<ref>{{cite web |url=https://www.kirj.ee/public/Engineering/2007/issue_4/eng-2007-4-2.pdf |title=Kirj.ee}}</ref> In 1833, [[Michael Faraday]] reported that the resistance of specimens of [[silver sulfide]] decreases when they are heated. This is contrary to the behavior of metallic substances such as copper. In 1839, [[Alexandre Edmond Becquerel]] reported observation of a voltage between a solid and a liquid electrolyte, when struck by light, the [[photovoltaic effect]]. In 1873, [[Willoughby Smith]] observed that [[selenium]] [[resistor]]s exhibit decreasing resistance when light falls on them. In 1874, [[Karl Ferdinand Braun]] observed conduction and [[rectifier|rectification]] in metallic [[sulfide]]s, although this effect had been discovered earlier by Peter Munck af Rosenschöld ([[:sv:Peter Munck af Rosenschöld|sv]]) writing for the ''Annalen der Physik und Chemie'' in 1835; Rosenschöld's findings were ignored.<ref name=":0">{{cite book |url=https://books.google.com/books?id=rslXJmYPjGIC&q=Semiconductor+Rectifier+Rosenschold&pg=PA24 |title=A History of the World Semiconductor Industry |first=Peter Robin |last=Morris |date=July 22, 1990 |publisher=IET |via=Google Books |isbn=9780863412271}}</ref> [[Simon Sze]] stated that Braun's research was the earliest systematic study of semiconductor devices.<ref>{{Cite book |last=Sze |first=Simon |author-link=Simon Sze |title=Semiconductor Devices: Physics and Technology |publisher=Wiley |year=2002 |isbn=9789971513955 |edition=2nd |pages=3}}</ref> Also in 1874, [[Arthur Schuster]] found that a copper oxide layer on wires had rectification properties that ceased when the wires are cleaned. [[William Grylls Adams]] and Richard Evans Day observed the photovoltaic effect in selenium in 1876.<ref name=JTIT10>{{cite journal |author1=Lidia Łukasiak |author2=Andrzej Jakubowski |name-list-style=amp |date=January 2010 |url=http://www.nit.eu/czasopisma/JTIT/2010/1/3.pdf |title=History of Semiconductors |journal=Journal of Telecommunication and Information Technology |page=3 |access-date=2012-08-03 |archive-date=2013-06-22 |archive-url=https://web.archive.org/web/20130622045329/http://www.nit.eu/czasopisma/JTIT/2010/1/3.pdf |url-status=dead }}</ref>

A unified explanation of these phenomena required a theory of [[solid-state physics]], which developed greatly in the first half of the 20th century. In 1878 [[Edwin Herbert Hall]] demonstrated the deflection of flowing charge carriers by an applied magnetic field, the [[Hall effect]]. The discovery of the [[electron]] by [[J.J. Thomson]] in 1897 prompted theories of electron-based conduction in solids. [[Karl Baedeker (scientist)|Karl Baedeker]], by observing a Hall effect with the reverse sign to that in metals, theorized that copper iodide had positive charge carriers. {{ill|Johan Koenigsberger|de|Johann Koenigsberger}} classified solid materials like metals, insulators, and "variable conductors" in 1914 although his student Josef Weiss already introduced the term '''''Halbleiter''''' (a semiconductor in modern meaning) in his Ph.D. thesis in 1910.<ref>{{cite journal |doi=10.1088/0143-0807/10/4/002 |volume=10 |issue=4 |title=Early history of the physics and chemistry of semiconductors-from doubts to fact in a hundred years |journal=European Journal of Physics |pages=254–64 |bibcode=1989EJPh...10..254B |year=1989 |last1=Busch |first1=G|s2cid=250888128 }}</ref><ref>{{cite web |url=https://books.google.com/books?id=oVBNQwAACAAJ |title=Experimentelle Beiträge Zur Elektronentheorie Aus dem Gebiet der Thermoelektrizität, Inaugural-Dissertation ... von J. Weiss, ... |first=Josef Weiss (de |last=Überlingen.) |date=July 22, 1910 |publisher=Druck- und Verlags-Gesellschaft |via=Google Books}}</ref> [[Felix Bloch]] published a theory of the movement of electrons through atomic lattices in 1928. In 1930, {{ill|B. Gudden|de|Bernhard Gudden}} stated that conductivity in semiconductors was due to minor concentrations of impurities. By 1931, the band theory of conduction had been established by [[Alan Herries Wilson]] and the concept of band gaps had been developed. [[Walter H. Schottky]] and [[Nevill Francis Mott]] developed models of the potential barrier and of the characteristics of a [[metal–semiconductor junction]]. By 1938, Boris Davydov had developed a theory of the copper-oxide rectifier, identifying the effect of the [[p–n junction]] and the importance of minority carriers and surface states.<ref name=":0" />

Agreement between theoretical predictions (based on developing quantum mechanics) and experimental results was sometimes poor. This was later explained by [[John Bardeen]] as due to the extreme "structure sensitive" behavior of semiconductors, whose properties change dramatically based on tiny amounts of impurities.<ref name=":0" /> Commercially pure materials of the 1920s containing varying proportions of trace contaminants produced differing experimental results. This spurred the development of improved material refining techniques, culminating in modern semiconductor refineries producing materials with parts-per-trillion purity.

Devices using semiconductors were at first constructed based on empirical knowledge before semiconductor theory provided a guide to the construction of more capable and reliable devices.

[[Alexander Graham Bell]] used the light-sensitive property of selenium to [[photophone|transmit sound]] over a beam of light in 1880. A working solar cell, of low efficiency, was constructed by [[Charles Fritts]] in 1883, using a metal plate coated with selenium and a thin layer of gold; the device became commercially useful in photographic light meters in the 1930s.<ref name=":0" /> Point-contact microwave detector rectifiers made of lead sulfide were used by [[Jagadish Chandra Bose]] in 1904; the [[cat's-whisker detector]] using natural galena or other materials became a common device in the [[history of radio|development of radio]]. However, it was somewhat unpredictable in operation and required manual adjustment for best performance. In 1906, [[H.J. Round]] observed light emission when electric current passed through [[silicon carbide]] crystals, the principle behind the [[light-emitting diode]]. [[Oleg Losev]] observed similar light emission in 1922, but at the time the effect had no practical use. Power rectifiers, using copper oxide and selenium, were developed in the 1920s and became commercially important as an alternative to [[vacuum tube]] rectifiers.<ref name=JTIT10/><ref name=":0" />

The first [[semiconductor device]]s used [[galena]], including German [[physicist]] Ferdinand Braun's [[crystal detector]] in 1874 and Indian physicist Jagadish Chandra Bose's [[radio]] crystal detector in 1901.<ref name="computerhistory-timeline">{{cite web |title=Timeline |url=https://www.computerhistory.org/siliconengine/timeline/ |website=The Silicon Engine |publisher=[[Computer History Museum]] |access-date=22 August 2019}}</ref><ref name="computerhistory-1901">{{cite web |title=1901: Semiconductor Rectifiers Patented as "Cat's Whisker" Detectors |url=https://www.computerhistory.org/siliconengine/semiconductor-rectifiers-patented-as-cats-whisker-detectors/ |website=The Silicon Engine |publisher=[[Computer History Museum]] |access-date=23 August 2019}}</ref>

In the years preceding World War II, infrared detection and communications devices prompted research into lead-sulfide and lead-selenide materials. These devices were used for detecting ships and aircraft, for infrared rangefinders, and for voice communication systems. The point-contact crystal detector became vital for microwave radio systems since available vacuum tube devices could not serve as detectors above about 4000&nbsp;MHz; advanced radar systems relied on the fast response of crystal detectors. Considerable research and development of [[silicon]] materials occurred during the war to develop detectors of consistent quality.<ref name=":0" />

=== Early transistors ===
{{Main article|History of the transistor}}
[[File:Bardeen Shockley Brattain 1948.JPG|thumb|[[John Bardeen]], [[William Shockley]] and [[Walter Brattain]] developed the bipolar [[point-contact transistor]] in 1947.]]

Detector and power rectifiers could not amplify a signal. Many efforts were made to develop a solid-state amplifier and were successful in developing a device called the [[point contact transistor]] which could amplify 20&nbsp;dB or more.<ref name="Morris90">Peter Robin Morris (1990) ''A History of the World Semiconductor Industry'', IET, {{ISBN|0-86341-227-0}}, pp. 11–25</ref> In 1922, [[Oleg Losev]] developed two-terminal, [[negative resistance]] amplifiers for radio, but he died in the [[Siege of Leningrad]] after successful completion. In 1926, [[Julius Edgar Lilienfeld]] patented a device resembling a [[field-effect transistor]], but it was not practical. {{ill|R. Hilsch|de|Rudolf Hilsch}} and {{ill|R. W. Pohl|de|Robert Wichard Pohl}} in 1938 demonstrated a solid-state amplifier using a structure resembling the control grid of a vacuum tube; although the device displayed power gain, it had a [[cut-off frequency]] of one cycle per second, too low for any practical applications, but an effective application of the available theory.<ref name=":0" /> At [[Bell Labs]], [[William Shockley]] and A. Holden started investigating solid-state amplifiers in 1938. The first p–n junction in silicon was observed by [[Russell Ohl]] about 1941 when a specimen was found to be light-sensitive, with a sharp boundary between p-type impurity at one end and n-type at the other. A slice cut from the specimen at the p–n boundary developed a voltage when exposed to light.

The first working [[transistor]] was a [[point-contact transistor]] invented by [[John Bardeen]], [[Walter Houser Brattain]], and [[William Shockley]] at Bell Labs in 1947. Shockley had earlier theorized a [[field-effect transistor|field-effect amplifier]] made from germanium and silicon, but he failed to build such a working device, before eventually using germanium to invent the point-contact transistor.<ref>{{cite web |title=1947: Invention of the Point-Contact Transistor |url=https://www.computerhistory.org/siliconengine/invention-of-the-point-contact-transistor/ |website=The Silicon Engine |publisher=Computer History Museum |access-date=23 August 2019}}</ref> In France, during the war, [[Herbert Mataré]] had observed amplification between adjacent point contacts on a germanium base. After the war, Mataré's group announced their "[[Transistron]]" amplifier only shortly after Bell Labs announced the "[[transistor]]".

In 1954, [[physical chemist]] [[Morris Tanenbaum]] fabricated the first silicon [[junction transistor]] at [[Bell Labs]].<ref>{{cite web |title=1954: Morris Tanenbaum fabricates the first silicon transistor at Bell Labs |url=https://www.computerhistory.org/siliconengine/silicon-transistors-offer-superior-operating-characteristics/ |website=The Silicon Engine |publisher=Computer History Museum |access-date=23 August 2019}}</ref> However, early [[junction transistor]]s were relatively bulky devices that were difficult to manufacture on a [[mass-production]] basis, which limited them to a number of specialised applications.<ref name="Moskowitz">{{cite book |last1=Moskowitz |first1=Sanford L. |title=Advanced Materials Innovation: Managing Global Technology in the 21st century |date=2016 |publisher=[[John Wiley & Sons]] |isbn=9780470508923 |page=168 |url=https://books.google.com/books?id=2STRDAAAQBAJ&pg=PA168}}</ref>