Field-effect transistor
transistor that uses an electric field to control its electrical behaviour
The field-effect transistor (FET) is a type of transistor that uses an electric field to control the current through a semiconductor. It comes in two types: junction FET (JFET) and metal–oxide–semiconductor FET (MOSFET). FETs have three terminals: source, gate, and drain. FETs control the current by the application of a voltage to the gate, which in turn alters the conductivity between the drain and source.
FETs are also known as unipolar transistors since they involve single-carrier-type operation. That is, FETs use either electrons (n-channel) or holes (p-channel) as charge carriers in their operation, but not both. Many different types of field-effect transistors exist. Field effect transistors generally display very high input impedance at low frequencies. The most widely used field-effect transistor is the MOSFET.
History
The concept of a field-effect transistor (FET) was first patented by the Austro-Hungarian born physicist Julius Edgar Lilienfeld in 1925 and by Oskar Heil in 1934, but they were unable to build a working practical semiconducting device based on the concept. The transistor effect was later observed and explained by John Bardeen and Walter Houser Brattain while working under William Shockley at Bell Labs in 1947, shortly after Lilienfeld's 17-year patent term expired.
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This entry incorporates text from “Field-effect transistor” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.