Discrete Semiconductor Devices, etc.
1940s
1947: Invention of the point-contact transistor (Bell Telephone Laboratories)
The point-contact transistor was invented at Bell Telephone Laboratories (BTL) in the U.S. in December 1947. Later, in April 1949, the germanium alloy transistor was also developed at BTL, and the grown-junction transistor was developed in 1951. These provided the foundation for the subsequent development of semiconductor devices.
The first point contact transistor
The first junction transisitor
