Editing Transistor (section)

==Types==
===Classification===
{{more citations needed|section|date=December 2020}}
<!-- START OF THE SYMBOLS -->
{{float_begin|side=right}}
|- style="text-align:center;"
|[[File:BJT PNP symbol.svg|80px]]||PNP||[[File:JFET P-Channel Labelled.svg|80px]]||P-channel
|- style="text-align:center;"
|[[File:BJT NPN symbol.svg|80px]]||NPN||[[File:JFET N-Channel Labelled.svg|80px]]||N-channel
|- style="text-align:center;"
|BJT||||JFET||
{{float_end|caption=BJT and JFET symbols}}

[[File:IGBT symbol.svg|thumb|right|Insulated-gate bipolar transistor (IGBT)]]

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|- style="text-align:center;"
|[[File:IGFET P-Ch Enh Labelled.svg|80px]]||[[File:IGFET P-Ch Enh Labelled simplified.svg|80px]]||[[File:IGFET P-Ch Dep Labelled.svg|80px]]||P-channel
|- style="text-align:center;"
|[[File:IGFET N-Ch Enh Labelled.svg|80px]]||[[File:IGFET N-Ch Enh Labelled simplified.svg|80px]]||[[File:IGFET N-Ch Dep Labelled.svg|80px]]||N-channel
|- style="text-align:center;"
|colspan="2"|MOSFET enh||MOSFET dep||
{{float_end|caption=MOSFET symbols}}
<!-- END OF THE SYMBOLS -->
Transistors are categorized by
* Structure: [[MOSFET]] (IGFET), [[Bipolar junction transistor|BJT]], [[JFET]], [[insulated-gate bipolar transistor]] (IGBT), other type.{{which|date=April 2021}}.
* Semiconductor material ([[dopant]]s): 
** The [[metalloids]]; [[germanium]] (first used in 1947) and [[silicon]] (first used in 1954)—in [[Amorphous silicon|amorphous]], [[Polycrystalline silicon|polycrystalline]] and [[Monocrystalline silicon|monocrystalline]] form.
** The compounds [[gallium arsenide]] (1966) and [[silicon carbide]] (1997).
** The [[alloy]] [[silicon–germanium]] (1989) 
** The [[allotrope of carbon]] [[Graphene#Electronics|graphene]] (research ongoing since 2004), etc. (see [[#Semiconductor material|Semiconductor material]]).
* [[Electrical polarity]] (positive and negative): [[NPN transistor|NPN]], [[PNP transistor|PNP]] (BJTs), N-channel, P-channel (FETs).
* Maximum [[power rating]]: low, medium, high.
* Maximum operating frequency: low, medium, high, [[radio frequency|radio]] (RF), [[microwave]] frequency (the maximum effective frequency of a transistor in a common-emitter or common-source circuit is denoted by the term {{math|''f''<sub>''T''</sub>}}, an abbreviation for [[gain–bandwidth product#Transistors|transition frequency]]—the frequency at which the transistor yields unity voltage gain)
* Application: switch, general purpose, audio, [[high voltage]], super-beta, matched pair.
* Physical packaging: [[through-hole technology|through-hole]] metal, through-hole plastic, [[Surface-mount technology|surface mount]], [[ball grid array]], power modules (see [[#Packaging|Packaging]]).
* Amplification factor [[Transistor models|{{math|''h''<sub>''FE''</sub>}}]], {{math|''β''<sub>''F''</sub>}} ([[transistor beta]])<ref>{{cite web|title=Transistor Example|url=http://www.bcae1.com/transres.htm|url-status=live|archive-url=https://web.archive.org/web/20080208150020/http://www.bcae1.com/transres.htm|archive-date=February 8, 2008}} 071003 bcae1.com</ref> or {{math|''g''<sub>''m''</sub>}} ([[transconductance]]).
* Working temperature: Extreme temperature transistors and traditional temperature transistors ({{convert|−55|to|150|C|F}}). Extreme temperature transistors include high-temperature transistors (above {{convert|150|C|F}}) and low-temperature transistors (below {{convert|-55|C|F}}). The high-temperature transistors that operate thermally stable up to {{convert|250|C|F}} can be developed by a general strategy of blending interpenetrating semi-crystalline conjugated polymers and high glass-transition temperature insulating polymers.<ref>{{Cite journal|last1=Gumyusenge|first1=Aristide|last2=Tran|first2=Dung T.|last3=Luo|first3=Xuyi|last4=Pitch|first4=Gregory M.|last5=Zhao|first5=Yan|last6=Jenkins|first6=Kaelon A.|last7=Dunn|first7=Tim J.|last8=Ayzner|first8=Alexander L.|last9=Savoie|first9=Brett M.|last10=Mei|first10=Jianguo|date=December 7, 2018|title=Semiconducting polymer blends that exhibit stable charge transport at high temperatures|journal=Science|language=en|volume=362|issue=6419|pages=1131–1134|doi=10.1126/science.aau0759|pmid=30523104|issn=0036-8075|bibcode=2018Sci...362.1131G|doi-access=free}}</ref>

Hence, a particular transistor may be described as ''silicon, surface-mount, BJT, NPN, low-power, high-frequency switch''.

===Mnemonics===
Convenient [[mnemonic]] to remember the type of transistor (represented by an [[electrical symbol]]) involves the direction of the arrow. For the [[Bipolar junction transistor|BJT]], on an '''n–p–n''' transistor symbol, the arrow will "'''N'''ot '''P'''oint i'''N"'''. On a '''p–n–p''' transistor symbol, the arrow "'''P'''oints i'''N''' '''P'''roudly". However, this does not apply to MOSFET-based transistor symbols as the arrow is typically reversed (i.e. the arrow for the n–p–n points inside).

===Field-effect transistor (FET)===
{{Main|Field-effect transistor}}
{{See also|JFET}}
[[File:Threshold formation nowatermark.gif|thumb|right|Operation of an [[FET]] and its {{mvar|I<sub>d</sub>}}-{{mvar|V<sub>g</sub>}} curve. At first, when no gate voltage is applied, there are no inversion electrons in the channel, so the device is turned off. As gate voltage increases, the inversion electron density in the channel increases, the current increases, and the device turns on.]]
The ''[[field-effect transistor]]'', sometimes called a ''unipolar transistor'', uses either electrons (in ''n-channel FET'') or holes (in ''p-channel FET'') for conduction. The four terminals of the FET are named ''source'', ''gate'', ''drain'', and ''body'' (''substrate''). On most FETs, the body is connected to the source inside the package, and this will be assumed for the following description.

In a FET, the drain-to-source current flows via a conducting channel that connects the ''source'' region to the ''drain'' region. The conductivity is varied by the electric field that is produced when a voltage is applied between the gate and source terminals, hence the current flowing between the drain and source is controlled by the voltage applied between the gate and source. As the gate–source voltage ({{mvar|V<sub>GS</sub>}}) is increased, the drain–source current ({{mvar|I<sub>DS</sub>}}) increases exponentially for {{mvar|V<sub>GS</sub>}} below threshold, and then at a roughly quadratic rate:  ({{math|''I<sub>DS</sub>'' ∝  (''V<sub>GS</sub>'' − ''V<sub>T</sub>'')<sup>2</sup>}}, where {{mvar|V<sub>T</sub>}} is the threshold voltage at which drain current begins)<ref name=horowitz-hill>{{cite book|last=Horowitz|first=Paul|author-link=Paul Horowitz|author2=Winfield Hill |title=The Art of Electronics|edition=2nd|year=1989|publisher=Cambridge University Press|isbn=978-0-521-37095-0|page=[115]|title-link=The Art of Electronics|author2-link=Winfield Hill}}</ref> in the [[space charge|space-charge-limited]] region above threshold. A quadratic behavior is not observed in modern devices, for example, at the [[65 nanometer|65 nm]] technology node.<ref name=Sansen>
{{cite book|author=Sansen, W. M. C. |title=Analog design essentials|year= 2006|page=§0152, p. 28|publisher=Springer|location=New York, Berlin|isbn=978-0-387-25746-4}}</ref>

For low noise at narrow [[bandwidth (signal processing)|bandwidth]], the higher input resistance of the FET is advantageous.

FETs are divided into two families: ''junction FET'' ([[JFET]]) and ''insulated gate FET'' (IGFET). The IGFET is more commonly known as a ''metal–oxide–semiconductor FET'' ([[MOSFET]]), reflecting its original construction from layers of metal (the gate), oxide (the insulation), and semiconductor. Unlike IGFETs, the JFET gate forms a [[p–n diode]] with the channel which lies between the source and drains. Functionally, this makes the n-channel JFET the solid-state equivalent of the vacuum tube [[triode]] which, similarly, forms a diode between its [[Control grid|grid]] and [[cathode]]. Also, both devices operate in the ''depletion-mode'', they both have a high input impedance, and they both conduct current under the control of an input voltage.

Metal–semiconductor FETs ([[MESFET]]s) are JFETs in which the [[Reverse-biased|reverse biased]] p–n junction is replaced by a [[metal–semiconductor junction]]. These, and the HEMTs (high-electron-mobility transistors, or HFETs), in which a two-dimensional electron gas with very high carrier mobility is used for charge transport, are especially suitable for use at very high frequencies (several GHz).

FETs are further divided into ''depletion-mode'' and ''enhancement-mode'' types, depending on whether the channel is turned on or off with zero gate-to-source voltage. For enhancement mode, the channel is off at zero bias, and a gate potential can ''enhance'' the conduction. For the depletion mode, the channel is on at zero bias, and a gate potential (of the opposite polarity) can ''deplete'' the channel, reducing conduction. For either mode, a more positive gate voltage corresponds to a higher current for n-channel devices and a lower current for p-channel devices. Nearly all JFETs are depletion-mode because the diode junctions would forward bias and conduct if they were enhancement-mode devices, while most IGFETs are enhancement-mode types.

====Metal–oxide–semiconductor FET (MOSFET)====
{{Main|MOSFET}}
The metal–oxide–semiconductor field-effect transistor ([[MOSFET]], MOS-FET, or MOS FET), also known as the metal–oxide–silicon transistor (MOS transistor, or MOS),<ref name="computer history-transistor"/> is a type of field-effect transistor that is [[Semiconductor device fabrication|fabricated]] by the [[thermal oxidation|controlled oxidation]] of a semiconductor, typically [[silicon]]. It has an insulated [[Metal gate|gate]], whose voltage determines the conductivity of the device. This ability to change conductivity with the amount of applied voltage can be used for amplifying or switching electronic [[signal (electrical engineering)|signals]]. The MOSFET is by far the most common transistor, and the basic building block of most modern [[electronics]].<ref name="triumph"/> The MOSFET accounts for 99.9% of all transistors in the world.<ref name="computerhistory2018">{{cite web |title=13 Sextillion & Counting: The Long & Winding Road to the Most Frequently Manufactured Human Artifact in History |url=https://www.computerhistory.org/atchm/13-sextillion-counting-the-long-winding-road-to-the-most-frequently-manufactured-human-artifact-in-history/ |date=April 2, 2018 |website=[[Computer History Museum]] |access-date=July 28, 2019}}</ref>

===Bipolar junction transistor (BJT)===
{{Main|Bipolar junction transistor}}
Bipolar transistors are so named because they conduct by using both majority and minority [[charge carrier|carriers]]. The bipolar junction transistor, the first type of transistor to be mass-produced, is a combination of two junction diodes and is formed of either a thin layer of p-type semiconductor sandwiched between two n-type semiconductors (an n–p–n transistor), or a thin layer of n-type semiconductor sandwiched between two p-type semiconductors (a p–n–p transistor). This construction produces two [[p–n junction]]s: a base-emitter junction and a base-collector junction, separated by a thin region of semiconductor known as the base region. (Two junction diodes wired together without sharing an intervening semiconducting region will not make a transistor.)

BJTs have three terminals, corresponding to the three layers of semiconductor—an ''emitter'', a ''base'', and a ''collector''. They are useful in [[amplifier]]s because the currents at the emitter and collector are controllable by a relatively small base current.<ref name=Streetman>{{cite book|last=Streetman|first=Ben|author-link=Ben G. Streetman|title=Solid State Electronic Devices|year=1992|publisher=Prentice-Hall|location=Englewood Cliffs, NJ|isbn=978-0-13-822023-5|pages=301–305}}</ref> In an n–p–n transistor operating in the active region, the emitter-base junction is forward-biased ([[electron]]s and [[electron hole|holes]] recombine at the junction), and the base-collector junction is reverse-biased (electrons and holes are formed at, and move away from, the junction), and electrons are injected into the base region. Because the base is narrow, most of these electrons will diffuse into the reverse-biased base-collector junction and be swept into the collector; perhaps one-hundredth of the electrons will recombine in the base, which is the dominant mechanism in the base current. As well, as the base is lightly doped (in comparison to the emitter and collector regions), recombination rates are low, permitting more carriers to diffuse across the base region. By controlling the number of electrons that can leave the base, the number of electrons entering the collector can be controlled.<ref name=Streetman/> Collector current is approximately β (common-emitter current gain) times the base current. It is typically greater than 100 for small-signal transistors but can be smaller in transistors designed for high-power applications.

Unlike the field-effect transistor (see below), the BJT is a low-input-impedance device. Also, as the base-emitter voltage (''V''<sub>BE</sub>) is increased the base-emitter current and hence the collector-emitter current (''I''<sub>CE</sub>) increase exponentially according to the [[diode modelling#Shockley diode model|Shockley diode model]] and the [[Ebers-Moll model]]. Because of this exponential relationship, the BJT has a higher [[transconductance]] than the FET.

Bipolar transistors can be made to conduct by exposure to light because the absorption of photons in the base region generates a photocurrent that acts as a base current; the collector current is approximately β times the photocurrent. Devices designed for this purpose have a transparent window in the package and are called [[phototransistor]]s.
[[File:2N2222A NPN Transsitor.jpg|alt=2N2222A NPN Transistor.|thumb|2N2222A NPN Transistor.]]

===Usage of MOSFETs and BJTs===
The [[MOSFET]] is by far the most widely used transistor for both [[digital circuit]]s as well as [[analog circuit]]s,<ref>{{cite web |title=MOSFET DIFFERENTIAL AMPLIFIER |url=http://sites.bu.edu/engcourses/files/2016/08/mosfet-differential-amplifier.pdf |website=[[Boston University]] |access-date=August 10, 2019}}</ref> accounting for 99.9% of all transistors in the world.<ref name="computerhistory2018"/> The [[bipolar junction transistor]] (BJT) was previously the most commonly used transistor during the 1950s to 1960s. Even after MOSFETs became widely available in the 1970s, the BJT remained the transistor of choice for many analog circuits such as amplifiers because of their greater linearity, up until MOSFET devices (such as [[power MOSFET]]s, [[LDMOS]] and [[RF CMOS]]) replaced them for most [[power electronic]] applications in the 1980s. In [[integrated circuit]]s, the desirable properties of MOSFETs allowed them to capture nearly all market share for digital circuits in the 1970s. Discrete MOSFETs (typically power MOSFETs) can be applied in transistor applications, including analog circuits, voltage regulators, amplifiers, power transmitters, and motor drivers.

===Other transistor types===
[[File:Transistor on portuguese pavement.jpg|thumb|A transistor symbol created on [[Portuguese pavement]] at the [[University of Aveiro]]]]
{{For|early bipolar transistors|Bipolar junction transistor#Bipolar transistors}}
* [[Field-effect transistor]] (FET):
** [[Metal–oxide–semiconductor field-effect transistor]] (MOSFET), where the gate is insulated by a shallow layer of insulator
*** [[PMOS logic|p-type MOS]] (PMOS)
*** [[NMOS logic|n-type MOS]] (NMOS)
*** [[CMOS|Complementary MOS]] (CMOS)
**** [[RF CMOS]], for [[radiofrequency]] amplification, reception
*** [[Multi-gate field-effect transistor]] (MuGFET)
**** [[Fin field-effect transistor]] (FinFET), source/drain region shapes fins on the silicon surface
****GAAFET, Similar to FinFET but nanowires are used instead of fins, the nanowires are stacked vertically and are surrounded on 4 sides by the gate
****  MBCFET, a variant of GAAFET that uses horizontal nanosheets instead of nanowires, made by Samsung. Also known as RibbonFET (made by Intel) and as horizontal nanosheet transistor.
*** [[Thin-film transistor]] (TFT), used in [[liquid-crystal display|LCD]] and [[OLED]] displays, types include amorphous silicon, LTPS, LTPO and IGZO transistors 
*** [[Floating-gate MOSFET]] (FGMOS), for [[non-volatile storage]]
*** [[Power MOSFET]], for power electronics
**** [[LDMOS|lateral diffused MOS]] (LDMOS)
** [[Carbon nanotube field-effect transistor]] (CNFET, CNTFET), where the channel material is replaced by a carbon nanotube
** Ferroelectric field-effect transistor ([[Fe FET]]), uses ferroelectric materials
** [[Junction gate field-effect transistor]] (JFET), where the gate is insulated by a reverse-biased p–n junction
** [[Metal–semiconductor field-effect transistor]] (MESFET), similar to JFET with a Schottky junction instead of a p–n junction
*** [[High-electron-mobility transistor]] (HEMT): GaN (gallium nitride), SiC (silicon carbide), Ga<sub>2</sub>O<sub>3</sub> (gallium oxide), GaAs (gallium arsenide) transistors, MOSFETs, etc.
** Negative-capacitance FET (NC-FET)
** [[Inverted-T field-effect transistor]] (ITFET)
** [[Fast-reverse epitaxial diode field-effect transistor]] (FREDFET)
** [[Organic field-effect transistor]] (OFET), in which the semiconductor is an organic compound
** [[Ballistic transistor (disambiguation)]]
** FETs used to sense the environment
*** [[Ion-sensitive field-effect transistor]] (ISFET), to measure ion concentrations in solution,
*** [[Electrolyte–oxide–semiconductor field-effect transistor]] (EOSFET), [[neurochip]],
*** [[Deoxyribonucleic acid field-effect transistor]] (DNAFET).
*** Field-effect transistor-based biosensor ([[Bio-FET]])
* [[Bipolar junction transistor]] (BJT):
** [[Heterojunction bipolar transistor]], up to several hundred GHz, common in modern ultrafast and RF circuits
** [[Schottky transistor]]
** [[avalanche transistor]]
** [[File: Darlington transistor MJ1000.jpg|thumb|A [[Darlington transistor]] with the upper case removed so the transistor chip (the small square) can be seen. It is effectively two transistors on the same chip. One is much larger than the other, but both are large in comparison to transistors in [[large-scale integration]] because this particular example is intended for power applications.]] [[Darlington transistor]]s are two BJTs connected together to provide a high current gain equal to the product of the current gains of the two transistors
** [[Insulated-gate bipolar transistor]]s (IGBTs) use a medium-power IGFET, similarly connected to a power BJT, to give a high input impedance. Power diodes are often connected between certain terminals depending on specific use. IGBTs are particularly suitable for heavy-duty industrial applications. The [[ASEA Brown Boveri]] (ABB) ''5SNA2400E170100'' ,<ref>{{cite web |url=http://library.abb.com/GLOBAL/SCOT/scot256.nsf/VerityDisplay/E700072B04381DD9C12571FF002D2CFE/$File/5SNA%202400E170100_5SYA1555-03Oct%2006.pdf |title=IGBT Module 5SNA 2400E170100 |access-date=June 30, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120426020121/http://library.abb.com/GLOBAL/SCOT/scot256.nsf/VerityDisplay/E700072B04381DD9C12571FF002D2CFE/$File/5SNA%202400E170100_5SYA1555-03Oct%2006.pdf |archive-date=April 26, 2012 }}</ref> intended for three-phase power supplies, houses three n–p–n IGBTs in a case measuring 38 by 140 by 190&nbsp;mm and weighing 1.5&nbsp;kg. Each IGBT is rated at 1,700 volts and can handle 2,400 amperes
** [[Phototransistor]].
** [[Emitter-switched bipolar transistor]] (ESBT) is a monolithic configuration of a high-voltage bipolar transistor and a low-voltage power MOSFET in [[cascode]] topology. It was introduced by STMicroelectronics in the 2000s,<ref>{{cite conference |doi=10.1109/IAS.2003.1257745 |title=A new monolithic emitter-switching bipolar transistor (ESBT) in high-voltage converter applications |first1=S. |last1=Buonomo |first2=C. |last2=Ronsisvalle |first3=R. |last3=Scollo |author4=STMicroelectronics  |author-link4=STMicroelectronics |first5=S. |last5=Musumeci |first6=R. |last6=Pagano |first7=A. |last7=Raciti |author8= University of Catania Italy |author-link8=University of Catania |date=October 16, 2003 |conference=38th IAS annual Meeting on Conference Record of the Industry Applications Conference |editor=IEEE |editor-link=Institute of Electrical and Electronics Engineers |volume=3 of 3 |location=Salt Lake City |pages=1810–1817  }}</ref> and abandoned a few years later around 2012.<ref>{{cite web |url=https://www.st.com/en/power-transistors/esbts.html?querycriteria=productId=SC1775 |title=ESBTs  |author=STMicroelectronics  |author-link=STMicroelectronics  |website=www.st.com|access-date=February 17, 2019 |quote=ST no longer offers these components, this web page is empty, and datasheets are obsoletes  }}</ref>
** [[Multiple-emitter transistor]], used in [[transistor–transistor logic]] and integrated current mirrors
** [[Multiple-base transistor]], used to amplify very-low-level signals in noisy environments such as the pickup of a [[record player]] or [[RF front end|radio front ends]]. Effectively, it is a very large number of transistors in parallel where, at the output, the signal is added constructively, but random noise is added only [[stochastic]]ally.<ref>Zhong Yuan Chang, Willy M. C. Sansen, ''Low-Noise Wide-Band Amplifiers in Bipolar and CMOS Technologies'', page 31, Springer, 1991 {{ISBN|0792390962}}.</ref>
* [[Tunnel field-effect transistor]], where it switches by modulating [[quantum tunneling]] through a barrier.
* [[Diffusion transistor]], formed by diffusing dopants into semiconductor substrate; can be both BJT and FET.
* [[Unijunction transistor]], which can be used as a simple pulse generator. It comprises the main body of either p-type or n-type semiconductor with ohmic contacts at each end (terminals ''Base1'' and ''Base2''). A junction with the opposite semiconductor type is formed at a point along the length of the body for the third terminal (''Emitter'').
* [[Single-electron transistor]]s (SET), consist of a gate island between two tunneling junctions. The tunneling current is controlled by a voltage applied to the gate through a capacitor.<ref>{{cite web |url=http://snow.stanford.edu/~shimbo/set.html |title=Single Electron Transistors |publisher=Snow.stanford.edu |access-date=June 30, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120426015942/http://snow.stanford.edu/~shimbo/set.html |archive-date=April 26, 2012 }}</ref>
* [[Nanofluidic transistor]], controls the movement of ions through sub-microscopic, water-filled channels.<ref>{{cite web |last=Sanders |first=Robert |url=http://www.berkeley.edu/news/media/releases/2005/06/28_transistor.shtml |title=Nanofluidic transistor, the basis of future chemical processors |publisher=Berkeley.edu |date=June 28, 2005 |access-date=June 30, 2012 |url-status=live |archive-url=https://web.archive.org/web/20120702182324/http://www.berkeley.edu/news/media/releases/2005/06/28_transistor.shtml |archive-date=July 2, 2012 }}</ref>
* [[Multigate device]]s:
** [[Tetrode transistor]]
** [[Pentode transistor]]
** [[Trigate transistor]] (prototype by Intel)
** [[Dual-gate field-effect transistor]]s have a single channel with two gates in [[cascode]], a configuration optimized for ''high-frequency amplifiers'', ''mixers'', and [[oscillators]].
* [[Junctionless nanowire transistor]] (JNT), uses a simple nanowire of silicon surrounded by an electrically isolated ''wedding ring'' that acts to gate the flow of electrons through the wire. 
* [[Nanoscale vacuum-channel transistor]], when in 2012, NASA and the National Nanofab Center in South Korea were reported to have built a prototype vacuum-channel transistor in only 150 nanometers in size, can be manufactured cheaply using standard silicon semiconductor processing, can operate at high speeds even in hostile environments, and could consume just as much power as a standard transistor.<ref>{{cite web |url=http://www.gizmag.com/nasa-vacuum-channel-transistor/22626/ |title=The return of the vacuum tube? |publisher=Gizmag.com |date=May 28, 2012 |access-date=May 1, 2016 |url-status=live |archive-url=https://web.archive.org/web/20160414122940/http://www.gizmag.com/nasa-vacuum-channel-transistor/22626/ |archive-date=April 14, 2016 }}</ref>
* [[Organic electrochemical transistor]].
* [[Solaristor]] (from solar cell transistor), a two-terminal gate-less self-powered phototransistor.
* Germanium–tin transistor<ref>{{cite web | url=https://www.azom.com/news.aspx?newsID=61206 | title=New Type of Transistor from a Germanium–Tin Alloy Developed | date=April 28, 2023 }}</ref>
* Wood transistor<ref>{{cite web | url=https://spectrum.ieee.org/wood-transistor | title=Timber! The World's First Wooden Transistor – IEEE Spectrum }}</ref><ref>{{cite web | url=https://www.theregister.com/2023/05/01/wooden_transistor_sweden/ | title=Boffins claim to create the world's first wooden transistor }}</ref>
* Paper transistor<ref>{{Cite web|url=https://spectrum.ieee.org/paper-transistor|title=Paper Transistor – IEEE Spectrum|website=[[IEEE]]}}</ref>
* [[Communicant Semiconductor Technologies|Carbon-doped silicon–germanium (Si–Ge:C)]] transistor
* Diamond transistor<ref>{{Cite web|url=https://spectrum.ieee.org/this-diamond-transistor-is-still-raw-but-its-future-looks-bright|title=This Diamond Transistor Is Still Raw, But Its Future Looks Bright – IEEE Spectrum|website=[[IEEE]]}}</ref>
* Aluminum nitride transistor<ref>{{Cite web|url=https://spectrum.ieee.org/aluminum-nitride|title=The New, New Transistor – IEEE Spectrum|website=[[IEEE]]}}</ref>
* Super-lattice castellated field effect transistors<ref>{{Cite web|url=https://semiengineering.com/chip-industry-week-in-review-23/|title=Chip Industry Week In Review|first=The SE|last=Staff|date=February 23, 2024|website=Semiconductor Engineering}}</ref>