John Bardeen was a true child prodigy, skipping fourth, fifth, and sixth grades and receiving a master's degree in physics at 21. With a Ph.D. from Harvard, he taught physics at the University of Minnesota until, in 1945, he was hired by Bell Laboratories, a high-tech communications and electronics research plant.
In the fall of 1947 Bardeen joined forces with William Shockley and Walter Brattain, who were already studying the possible use of semiconductor materials in electronics. Shockley shared the “industrial dream” of freeing electronics from the bulkiness, fragility, heat production, and high power consumption of the vacuum tube. To allow semi conductors to replace tubes, Shockley had to make semiconductor material both amplify and rectify electric signals. All of his attempts had failed.
Bardeen first studied and confirmed that Shockley's math matics were correct and that his approach was consistent with accepted theory. Shockley's experiments should work. But the results they found using germanium, a common semiconductor, didn't match the theory.
Bardeen guessed that unspecified surface interference on the germanium must be blocking the electric current. The three men set about test ing the responses of semi conductor surfaces to light, heat, cold, liquids, and the deposit of metallic films. On wide lab benches they tried to force electric current into the germanium through liquid metals and then through soldered wire contact points. Most of November and much of Decem ber 1947 were consumed with these tests.
They found that the contact points worked, sort of. A strong current could be forced through the germanium to a metal base on the other side. But rather than amplifying a signal (making it stronger), it actually consumed energy (made it weaker).
Then Bardeen noticed some thing odd and unexpected. He accidentally misconnected his electrical leads, sending a microcurrent to the germanium contact point. When a very weak current was trickled through from wire solder point to base, it created a “hole” in the germanium's resistance to current flow. A weak current converted the semi conductor into a superconductor.
Bardeen had to repeat edly demonstrate the phenomenon to convince both himself and his teammates that his amazing results weren't fluke occurrences. Time after time the results were the same with any semi conductor material they tried: high current, high resistance; low current, virtually no resistance.
Bardeen named the phenomenon “transfer resistors,” or transistors. It provided engineers with a way to both rectify a weak signal and boost it to many times its original strength. Transis tors required only 1/50 the space of a vacuum tube and 1/1,000,000 the power and could outperform vacuum tubes.
For this discovery, the three men shared the 1956 Nobel Prize for Physics.
