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In 1919, the year tetrodes were invented, William Henry Eccles coined the term diode from the Greek roots di (from δί), meaning 'two', and ode (from οδός), meaning 'path'. The word diode however was already in use, as were triode, tetrode, pentode, hexode, as terms of multiplex telegraphy. [23]
The first Light-Emitting Diode was created in 1927 by Russian inventor Oleg Losev, [1] and used silicon carbide as a semiconductor. However, electroluminescence as a phenomenon was discovered twenty years earlier by the English experimenter Henry Joseph Round of Marconi Labs , using the same crystal and a cat's-whisker detector .
German inventor Karl Ferdinand Braun invented cathode ray oscilloscope (CRO). 1901: First transatlantic radio transmission by Guglielmo Marconi 1901: American engineer Peter Cooper Hewitt invented the Fluorescent lamp. 1904: English engineer John Ambrose Fleming invented the diode. 1906: American inventor Lee de Forest invented the triode. 1908
1962 Nick Holonyak Jr. develops the first practical visible-spectrum (red) light-emitting diode. 1963 Kurt Schmidt invents the first high pressure sodium-vapor lamp. [18] 1972 M. George Craford invents the first yellow light-emitting diode. 1972 Herbert Paul Maruska and Jacques Pankove create the first violet light-emitting diode.
In an organic light-emitting diode , the electroluminescent material composing the emissive layer of the diode is an organic compound. The organic material is electrically conductive due to the delocalization of pi electrons caused by conjugation over all or part of the molecule, and the material therefore functions as an organic semiconductor ...
The first low-powered LEDs were developed in the early 1960s, and only produced light in the low, red frequencies of the spectrum. In 1968, the first commercial LED lamps were introduced: Hewlett-Packard's LED display, [11] which was developed under Howard C. Borden and Gerald P. Pighini, and Monsanto Company's LED indicator lamp. [11]
Metropolitan Vickers Ltd rebuilt the full 200 transistor (& 1300 diode) design in 1956 using junction transistors (for internal use). [61] The IBM 7070 (1958), IBM 7090 (1959), and CDC 1604 (1960) were the first computers (as products for sale) based on transistors.
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 thermionic vacuum tubes it replaced worked by controlling a current of ...