Glossary / Semiconductors
Transistor
A semiconductor device in which a small signal controls a larger current, so it can amplify or switch. The basic component of all electronics.
In December 1947 John Bardeen and Walter Brattain at Bell Labs amplified a signal with a germanium crystal touched by two fine contacts. Their 1948 paper was titled "The Transistor, A Semi-Conductor Triode" — a solid-state replacement for the vacuum tube[1].
Inside a computer, transistors are used as on-off switches. Because combinations of switches perform logic, making transistors smaller and packing in more of them has translated directly into more computing power.
Related terms
- p-n junctionThe boundary between n-type semiconductor, rich in electrons, and p-type, rich in holes. It lets current flow in only one direction.
- MOS transistorA transistor built from a metal electrode, an oxide layer and a semiconductor, in which a voltage on the electrode alone opens and closes the channel. Most of today's chips are made of these.
- Integrated circuitA circuit in which transistors and other components, together with the wiring between them, are all built into a single piece of semiconductor — a chip.