After World War II the people at Bell Labs could resume its focus on basic research and development. The middle chapters of Crystal Fire give many details about this period through the early 1950s. They learned many things about the electrical property of different elements, compounds, combinations, of solid state devices. They also encountered mysteries about these things that prompted further research. They also had to spend considerable time obtaining samples of materials absent undesired impurities or optimal amounts of desired impurities. Patents were filed and there were concerns about patents already in place, what exclusive rights the military might want, and what progress was being in other labs such as at Purdue University.
There were two types of transistors invented at Bell Labs during those years – the point contact invented by John Bardeen and Walter Brattain and the junction type spearheaded by William Shockley.
In June 1951 Bell Labs gave a press conference about transistors. The star of the show was the junction transistor. Perhaps its most remarkable feature was its extremely low power consumption, about one-millionth of conventional vacuum tubes. It also amplified signals with far greater efficiency than the point-contact transistor.
The point-contact transistor was still used in the Bell System. Practical use of it came earlier. It entered mass production at Western Electric (a subsidiary of AT&T), servicing complex switching equipment to permit direct dialing and bypassing traditional telephone operators.
But the point-contact transistor never made it to the commercial marketplace in a big way. Apart from transient usage in hearing aids and military equipment, the only important applications it ever found came in the Bell System. Other manufacturers were reluctant to put significant capital into its production, especially after the recent breakthrough by Shockley’s team. The future belonged to the junction transistor and its offspring.