The Birth of the Transistor: William Shockley's Groundbreaking Patent of 1948

On June 26, 1948, Bell Labs physicist William Shockley filed a patent application for a new type of semiconductor device: the junction transistor. This concept later became the foundation of the first practical bipolar transistor and the earliest generation of microelectronics. Shockley proposed a different design based on p-n junctions within a germanium crystal. It proved much easier to manufacture on a large scale and became the basis for most of the transistors that followed.

A transistor is a tiny electronic switch and signal amplifier. Imagine an electrical circuit as a network of water pipes: a transistor works like a valve, where a small control signal opens or closes the flow of a much larger electric current. This allows transistors to perform logic operations and store bits of information (very roughly speaking, a closed transistor represents a 0, while an open transistor represents a 1).

Before transistors, computers relied on vacuum tubes. Machines like ENIAC contained tens of thousands of them, filled entire rooms, consumed enormous amounts of electricity, and failed regularly. Replacing vacuum tubes with transistors made computers dramatically smaller, faster, cheaper, and more reliable. By the late 1950s, the first fully transistorized computers had appeared, and just a few years later engineers learned how to place dozens, then hundreds, and eventually millions of transistors onto a single piece of semiconductor material. This led to the invention of integrated circuits and, ultimately, microprocessors.

Today, nearly every electronic device — a smartphone, laptop, server, router, SSD, or graphics card — contains chips with billions of transistors. Although modern transistors are built differently and measure only a few nanometers across, their operating principle can be traced directly back to the idea that William Shockley patented on June 26, 1948.

See also The Birth of Transistor Computing: Bell Labs’ TRADIC Revolution in 1955.