John Bardeen in the context of "William Shockley"

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.

The semiconductor industry is the aggregate of companies engaged in the design and fabrication of semiconductors and semiconductor devices, such as transistors and integrated circuits. Its roots can be traced to the invention of the transistor by Shockley, Brattain, and Bardeen at Bell Labs in 1948. Bell Labs licensed the technology for $25,000, and soon many companies, including Motorola (1952), Shockley Semiconductor (1955), Sylvania, Centralab, Fairchild Semiconductor and Texas Instruments were making transistors. In 1958 Jack Kilby of Texas Instruments and Robert Noyce of Fairchild independently invented the Integrated Circuit, a method of producing multiple transistors on a single "chip" of Semiconductor material. This kicked off a number of rapid advances in fabrication technology leading to the exponential growth in semiconductor device production, known as Moore's law that has persisted over the past six or so decades. The industry's annual semiconductor sales revenue has since grown to over $481 billion, as of 2018.

In 2010, the semiconductor industry had the highest intensity of Research & Development in the EU and ranked second after Biotechnology in the EU, United States and Japan combined.

In physics, the Bardeen–Cooper–Schrieffer (BCS) theory (named after John Bardeen, Leon Cooper, and John Robert Schrieffer) is the first microscopic theory of superconductivity since Heike Kamerlingh Onnes's 1911 discovery. The theory describes superconductivity as a microscopic effect caused by a condensation of Cooper pairs. The theory is also used in nuclear physics to describe the pairing interaction between nucleons in an atomic nucleus.

It was proposed by Bardeen, Cooper, and Schrieffer in 1957; they received the Nobel Prize in Physics for this theory in 1972.

The Society of Fellows is a group of scholars selected at the beginnings of their careers by Harvard University for their potential to advance academic wisdom, upon whom are bestowed distinctive opportunities to foster their individual and intellectual growth. Junior fellows are appointed by senior fellows based upon previous academic accomplishments and receive generous financial support for three years while they conduct independent research at Harvard University in any discipline, without being required to meet formal degree requirements or to be graded in any way. The only stipulation is that they maintain primary residence in Cambridge, Massachusetts, for the duration of their fellowship. Membership in the society is for life.

The society has contributed numerous scholars to the Harvard faculty and thus significantly influenced the tenor of discourse at the university. Among its best-known members are philosopher W. V. O. Quine, Jf '36; behaviorist B. F. Skinner, Jf '36; double Nobel laureate John Bardeen, Jf '38; economist Paul Samuelson, Jf '40; historian Arthur M. Schlesinger, Jr., Jf '43; presidential advisor McGeorge Bundy, Jf '48; historian and philosopher of science Thomas Kuhn, Jf '51; linguist and activist Noam Chomsky, Jf '55; biologist E. O. Wilson, Jf '56; cognitive scientist Marvin Minsky, Jf '57; former dean of the Harvard faculty, economist Henry Rosovsky, Jf '57; economist and whistleblower Daniel Ellsberg, Jf '59; philosopher Saul Kripke, Jf '66; ethnographer and photographer Bruce Jackson, Jf '67; Fields Medal-winning theoretical physicist Ed Witten, Jf '81; and writer, critic, and editor Leon Wieseltier, Jf '82.

The point-contact transistor was the first type of transistor to be successfully demonstrated. It was developed by research scientists John Bardeen and Walter Brattain at Bell Laboratories in December 1947. They worked in a group led by physicist William Shockley. The group had been working together on experiments and theories of electric field effects in solid state materials, with the aim of replacing vacuum tubes with a smaller device that consumed less power.

The critical experiment, carried out on December 16, 1947, consisted of a block of germanium, a semiconductor, with two very closely spaced gold contacts held against it by a spring. Brattain attached a small strip of gold foil over the point of a plastic triangle—a configuration which is essentially a point-contact diode. He then carefully sliced through the gold at the tip of the triangle. This produced two electrically isolated gold contacts very close to each other.

Walter Houser Brattain (/ˈbrætn/ BRAT-n; February 10, 1902 – October 13, 1987) was an American solid-state physicist who shared the 1956 Nobel Prize in Physics with John Bardeen and William Shockley for their invention of the point-contact transistor. Brattain devoted much of his life to research on surface states.