Electronics devoted its cover to a picture of Shockley, Brattain, and Bardeen, with a caption “Revolutionary amplifier: the crystal triode.” The New York Times covered the story in a few paragraphs on page 46 at the end of a column titled “The News of Radio.” The technical press was far more receptive. The revolutionary importance of the invention was not apparent to all attending. On 30 June 1948, Bell Labs held a press conference in New York to introduce the transistor. Bell Labs soon named the device the “ transistor.” It was this device they showed to Labs leadership the next week. Bardeen and Brattain were the first to succeed, On 16 December 1947, they for the first time amplified an electrical signal with a solid state device, a point-contact semiconductor amplifier. Shockley’s own efforts focused on the field-effect, while Bardeen and Brattain investigated ways to reduce the effects of surface states to make a viable solid-state device. Now the work focused on the semiconductor elements germanium and silicon, because understanding of these had advanced greatly during the war from their development as crystal diode rectifiers in radar. Kelly reactivated the solid state amplifier/switch project in 1945, creating a new and larger group under the direction of Shockley and chemist Stanley Morgan, and including experimental physicist Walter Brattain and newly hired theoretical physicist John Bardeen. In 1940-1941, this project, along with almost everything else at Bell Labs, was put aside for war work. Shockley and a handful of colleagues began working on the problem, concentrating on theoretical work and on well understood semiconductors such as copper oxide. Kelly’s very first hire as research director was for this program, a young theoretical physicist from MIT, William Shockley. His hope was that a program of basic research in this area would lead to solid state electronic replacements for both the millions of moving, clanking electromechanical relays that were the chief components of telephone switches, and the bulky, hot, fragile vacuum tubes used to amplify telephone signals. Mervin Kelly, then newly promoted to the post of Director of Research, decided to form a research group on solid-state physics. This first demonstration was just one milestone on a research trajectory that had its start back in 1936. And unlike vacuum tubes (the then-standard electronic device), the amplification was instantaneous no warm-up time was required. They switched their invention in and out of an audio circuit, so those gathered could clearly hear the sound being amplified. A group of senior Bell Labs scientists and administrators gathered in a laboratory where physicists John Bardeen and Walter Brattain were about to demonstrate the first solid state amplifier, the point-contact transistor.

23 December 1947 was a snowy early winter day at Bell Telephone Laboratories in Murray Hill, N.J.

Quien invento el radio transistor