Walter Brattain in the context of "Surface states"

A transistor is a semiconductor device used to amplify or switch electrical signals and power. It is one of the basic building blocks of modern electronics. It is composed of semiconductor material, usually with at least three terminals for connection to an electronic circuit. A voltage or current applied to one pair of the transistor's terminals controls the current through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Some transistors are packaged individually, but many more in miniature form are found embedded in integrated circuits. Because transistors are the key active components in practically all modern electronics, many people consider them one of the 20th century's greatest inventions.

Physicist Julius Edgar Lilienfeld proposed the concept of a field-effect transistor (FET) in 1925, but it was not possible to construct a working device at that time. The first working device was a point-contact transistor invented in 1947 by physicists John Bardeen, Walter Brattain, and William Shockley at Bell Labs who shared the 1956 Nobel Prize in Physics for their achievement. The most widely used type of transistor, the metal–oxide–semiconductor field-effect transistor (MOSFET), was invented at Bell Labs between 1955 and 1960. Transistors revolutionized the field of electronics and paved the way for smaller and cheaper radios, calculators, computers, and other electronic devices.

John Bardeen (May 23, 1908 – January 30, 1991) was an American condensed matter physicist. He is the only person to be awarded the Nobel Prize in Physics twice: first in 1956 with William Shockley and Walter Brattain for their invention of the transistor; and again in 1972 with Leon Cooper and Robert Schrieffer for their microscopic theory of superconductivity, known as the BCS theory.

Born and raised in Wisconsin, Bardeen earned both his bachelor's and master's degrees in electrical engineering from the University of Wisconsin, before receiving a Ph.D. in physics from Princeton University. After serving in World War II, he was a researcher at Bell Labs and a professor at the University of Illinois.

William Bradford Shockley (February 13, 1910 – August 12, 1989) was an American applied physicist. He was the manager of a research group at Bell Labs that included John Bardeen and Walter Brattain. The three scientists were jointly awarded the 1956 Nobel Prize in Physics "for their researches on semiconductors and their discovery of the transistor effect."

Partly as a result of Shockley's attempts to commercialize a new transistor design in the 1950s and 1960s, California's Silicon Valley became a hotbed of electronics innovation. He recruited brilliant employees, but quickly alienated them with his autocratic and erratic management; they left and founded major companies in the industry.