Transistor
Transistor, a solid-state device used in electronic circuits primarily as an amplifier or switch. Almost all modern electronic equipment makes use of transistors. In miniaturized form, they are essential components of computers. Transistors are made of semiconducting materials, such as silicon or germanium. They are produced in a variety of sizes and shapes. A conventional transistor is enclosed in a protective casing and has three electrical leads. Transistors that are components of an integrated circuit are formed on the surface of a single chip of semiconducting material and can be microscopic in size.
The transistor was invented by William Shockley, John Bardeen, and Walter H. Brattain of the Bell Telephone Laboratories in 1948.