History of the transistor about 15 volts". Brattain and H. R. Moore made a demonstration to several of their colleagues and managers at Bell Labs on the afternoon of 23 December 1947, often given as the birth date of the transistor. The "PNP point-contact germanium transistor" operated as a speech amplifier with a power gain of 18 in that trial. In 1956 John Bardeen, Walter Houser Brattain, and William Bradford Shockley were honored with the Nobel Prize in Physics "for their researches on semiconductors and their discovery of the transistor effect". Twelve people are mentioned as directly involved in the invention of the transistor
History of the transistor and Y. Watanabe in 1950, and was finally able to produce some experimental prototypes in 1975. It was the fastest transistor through to the 1980s. Further developments included the grown-junction transistor (1951), the surface-barrier transistor (1953), the diffusion transistor, the tetrode transistor, and the pentode transistor. The diffused silicon 'mesa transistor' was developed at Bell in 1955 and made commercially available by Fairchild Semiconductor in 1958. The spacistor was a type of transistor developed in the 1950s as an improvement over the point-contact transistor and the later alloy junction transistor. In 1953, Philco had developed the world's first high frequency