Shortly after the end of the war in 1945, Bell Labs formed a Solid State Physics Group, led by Shockley and chemist Stanley Morgan; other personnel including
Bardeen and Brattain, physicist Gerald Pearson, chemist Robert Gibney, electronics expert Hilbert Moore and several technicians. Their assignment was to seek a solid-state alternative to fragile glass
vacuum tube amplifiers. Their first attempts were based on Shockley's ideas about using an external electrical field on a semiconductor to affect its conductivity. These experiments mysteriously failed every time in all sorts of configurations and materials. The group was at a standstill until Bardeen suggested a theory that invoked surface states that prevented the field from penetrating the semiconductor. The group changed its focus to study these surface states and they met almost daily to discuss the work. The rapport of the group was excellent, and ideas were freely exchanged. By the winter of 1946 they had enough results that Bardeen submitted a paper on the surface states to
Physical Review. Brattain started experiments to study the surface states through observations made while shining a bright light on the semiconductor's surface. This led to several more papers (one of them co-authored with Shockley), which estimated the density of the surface states to be more than enough to account for their failed experiments. The pace of the work picked up significantly when they started to surround point contacts between the semiconductor and the conducting wires with
electrolytes. Moore built a circuit that allowed them to vary the frequency of the input signal easily and suggested that they use
glycol borate (gu), a viscous chemical that didn't evaporate. Finally they began to get some evidence of power amplification when Pearson, acting on a suggestion by Shockley, put a voltage on a droplet of gu placed across a
P-N junction.
December of 1947 was
Bell Labs' "Miracle Month," when Bardeen and Brattain -- working without Shockley -- succeeded in creating a
point-contact transistor that achieved amplification. By the next month,
Bell Lab's patent attorneys started to work on the patent applications.
Bell Labs attorneys soon discovered that Shockley's field effect principle had been anticipated and patented in 1930 by
Julius Lilienfeld. Although the patent appeared "breakable" (it could not work) the patent attorneys based one of its four patent applications only on the Bardeen-Brattain point contact design. Three others submitted at the same time covered the electrolyte-based transistors with Bardeen, Gibney and Brattain as the inventors. Shockley's name was not on any of these patent applications. This angered Shockley, who thought his name should also be on the patents because the work was based on his field effect idea. He even made efforts to have the patent written only in his name, and told Bardeen and Brattain of his intentions.
At the same time he secretly continued his own work to build a different sort of transistor based on junctions instead of point contacts; he expected this kind of design would be more likely to be viable commercially. Shockley worked furiously on his magnum opus,
Electrons and Holes in Semiconductors which was finally published as a 558 page treatise in 1950. In it, Shockley worked out the critical ideas of drift and diffusion and the differential equations that govern the flow of electrons in solid state crystals.
Shockley's diode equation is also described. This seminal work became the "bible" for an entire generation of scientists working to develop and improve new variants of the transistor and other devices based on semiconductors.
Shockley was dissatisfied with certain parts of the explanation for how the point contact transistor worked and conceived of the possibility of minority carrier injection. This led Shockley to ideas for what he called a "sandwich transistor." This resulted in the
junction transistor, which was announced at a press conference on July 4, 1951. Shockley obtained a patent for this invention on September 25, 1951. Different fabrication methods for this device were developed but the "diffused-base" method became the method of choice for many applications. It soon eclipsed the point contact transistor, and it and its offspring became overwhelmingly dominant in the marketplace for many years. Shockley continued as a group head to lead much of the effort at Bell Labs to improve it and its fabrication for two more years.
In 1951, he was elected a member of the
National Academy of Sciences (NAS). He was forty-one years old; this was rather young for such an election. Two years later, he was chosen as the recipient of the prestigious
Comstock Prize for Physics by the NAS, and was the recipient of many other awards and honors.
The ensuing publicity generated by the "invention of the transistor" often thrust Shockley to the fore, much to the chagrin of Bardeen and Brattain. Bell Labs management, however, consistently presented all three inventors as a team. Shockley eventually infuriated and alienated Bardeen and Brattain, and he essentially blocked the two from working on the junction transistor. Bardeen began pursuing a theory for superconductivity and left Bell Labs in 1951. Brattain refused to work with Shockley further and was assigned to another group. Neither Bardeen nor Brattain had much to do with the development of the transistor beyond the first year after its invention.
Shockley's abrasive management style caused him to be passed over for executive promotion at Bell Labs, which also felt he was a greater asset as a research scientist and theorist. Shockley wanted the power and profit he felt he deserved. He took a leave from Bell Labs in 1953 and moved back to the
California Institute of Technology (Caltech) for four months as a visiting professor.