The term solid-state became popular at the beginning of the semiconductor era in the 1960s to distinguish this new technology. A semiconductor device works by controlling an electric current consisting of electrons or holes moving within a solid crystalline piece of semiconducting material such as silicon, while the thermionicvacuum tubes it replaced worked by controlling a current of electrons or ions in a vacuum within a sealed tube.
Although the first solid-state electronic device was the cat's whisker detector, a crude semiconductor diode invented around 1904, solid-state electronics started with the invention of the transistor in 1947.[7] Before that, all electronic equipment used vacuum tubes, because vacuum tubes were the only electronic components that could amplify—an essential capability in all electronics. The transistor, which was invented by John Bardeen and Walter Houser Brattain while working under William Shockley at Bell Laboratories in 1947,[8] could also amplify, and replaced vacuum tubes. The first transistor hi-fi system was developed by engineers at GE and demonstrated at the University of Philadelphia in 1955.[9] In terms of commercial production, The Fisher TR-1 was the first "all transistor" preamplifier, which became available mid-1956.[10] In 1961, a company named Transis-tronics released a solid-state amplifier, the TEC S-15.[11]
Also during the 1960s and 1970s, television set manufacturers switched from vacuum tubes to semiconductors, and advertised sets as "100% solid state"[12] even though the cathode-ray tube (CRT) was still a vacuum tube. It meant only the chassis was 100% solid-state, not including the CRT. Early advertisements spelled out this distinction,[13] but later advertisements assumed the audience had already been educated about it and shortened it to just "100% solid state". LED displays can be said to be truly 100% solid-state.[14]
^"Solid state device". Encyclopaedia Britannica online. Encyclopaedia Britannica Inc. 2017. Archived from the original on August 1, 2017. Retrieved December 5, 2017.
^Campardo, Giovanni; Tiziani, Federico; Iaculo, Massimo (2011). Memory Mass Storage. Springer Science and Business Media. p. 85. ISBN978-3642147524. Archived from the original on 2017-12-29.