A device composed of semiconductor material that amplifies a signal or opens or closes a circuit. Transistors have become the major componet in all digital circuits, including computer microprocessors which now contain millions of microscopic size transistors. Prior to transistors, digital circuits used vacuum tubes, which had many disadvantages. They were larger, used more energy and created more heat.
Bardeen, Shockley, and Brattain, scientists at the Bell Telephone Laboratories in Murray Hill, New Jersey, were researching the behavior of crystals (germanium) as semi-conductors in an attempt to replace vacuum tubes as mechanical relays in telecommunications. The vacuum tube had been used to amplify music and voic, and it had made long-distance calling practical, but the tubes consumed power, created heat and burned out rapidly requiring high maintenance.
The teams' research was about to come to a fruitless end when a last attempt to try a purer substance as a contact point was made, and the "point-contact" transistor amplifier was invented. In 1956, the team was rewarded with the Nobel Prize in Physics for the invention of the transistor.
Bardeen and Brattain, took out a patent for a transistor, Shockley, applied for a patent for the transistor effect and a transistor amplifier. Transistors transformed the world of electronics and had a huge impact on how computers were designed, after their invention, transistors made of semiconductors replaced tubes in the construction of computers.