Semiconductor Transistor
Year of Discovery: 1947
What Is It? Semiconductor material can be turned, momentarily, into a superconductor.
Who Discovered It? John Bardeen
Why Is This One of the 100 Greatest?
John Bardeen won his first Nobel Prize for discovering the transistor effect of semiconductor materials. Most materials either conduct electric flow (conductors) or block that
flow (insulators). But a few materials sometimes permitted some electric flow (semiconductors). Though they had been identified by the late 1800s, no one knew the value of semiconductors until Bardeen discovered the transistor effect.
The transistor has been the backbone of every computing, calculating, communicating, and logic electronics chip and circuit built in the last 50 years. The transistor revolutionized the worlds of electronics and made most of the modern pieces of essential
electronic and computing hardware possible. There is no area of life or science that has not
been deeply affected by this one discovery
How Was It Discovered?
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 semiconductors 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 mathematics 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 testing the responses of semiconductor surfaces to light, heat, cold, liquids, and the deposit of metallic films. On wide lab
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