Transistor
The transistor is the fundamental building block of modern electronic devices, and is ubiquitous in modern electronic systems. Julius Edgar Lilienfeld patented a field-effect transistor in 1926 but it was not possible to actually construct a working device at that time. The first practically implemented device was a point-contact transistor invented in 1947 by American physicists John Bardeen, Walter Brattain, and William Shockley. The transistor revolutionized the field of electronics, and paved the way for smaller and cheaper radios, calculators, and computers, among other things. The transistor is on the list of IEEE milestones in electronics, and Bardeen, Brattain, and Shockley shared the 1956 Nobel Prize in Physics for their achievement.
Ian Munro Ross
In 1952 William Shockley hired him to work in semiconductors at Bell Labs, and he arrived in Murray Hill just after John Bardeen and Walter Houser Brattain had left. Shockley's group focused exclusively on transistor improvements, and Ross and G. C. Dacey were instrumental in the early stages of development of the field-effect transistor. In 1960 Ross and others invented epitaxy. He subsequently rose through managerial ranks, ultimately serving as the sixth President of Bell Labs 1979–1991 and overseeing its reorganization following the breakup of the Bell System.