Britannica Sources used in this answer

How did Bell Labs contribute to the development of the transistor?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

NMOS transistorNegative-channel metal-oxide semiconductors (NMOS) employ a positive secondary voltage to switch a shallow layer of p-type semiconductor material below the gate into n-type. For positive-channel metal-oxide semiconductors (PMOS), all these polarities are reversed. NMOS transistors are more expensive, but faster, than PMOS transistors. — transistor NMOS transistor
Negative-channel metal-oxide semiconductors (NMOS) employ a positive secondary voltage to switch a shallow layer of p-type semiconductor material below the gate into n-type. For positive-channel metal-oxide semiconductors (PMOS), all these polarities are reversed. NMOS transistors are more expensive, but faster, than PMOS transistors.

Bell Labs played a pivotal role in the development of the transistor by fostering a dedicated solid-state research program aimed at finding alternatives to electron-tube amplifiers for the telephone system.1

In 1945, director of research Mervin Kelly reorganized the lab, tasking a team led by William B. Shockley with developing a solid-state amplifier. After initial failures, theoretical physicist John Bardeen identified that "surface-state" electrons were hindering device performance. This insight led Walter H. Brattain to discover a method to neutralize these effects, resulting in the invention of the point-contact transistor on December 16, 1947.1

Shortly thereafter, Shockley conceived the bipolar junction transistor, a more manufacturable design. The term "transistor" was coined by Bell Labs engineer John Robinson Pierce. The company’s commitment to basic research and its ability to solve complex material science challenges—such as creating ultrapure germanium and silicon—were essential to the successful development and eventual mass production of these revolutionary components.12