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Karl Ferdinand Braun (1850-1918), German physicist and inventor. In 1874 Braun discovered one way conduction in metal sulphide crystals and created the first semiconductor. This later led to the invention of the crystal rectifier, which improved Marconi's wireless system and in 1909 they shared the Nobel prize in physics. Braun also adapted his cathode ray tube so that a narrow beam of electrons within it could be deflected by an alternating voltage. With this he invented the oscilloscope and aided the development of television. In 1917 he was summoned to America to appear as a witness in court. Due to the start of World War I he was unable to return home and died in New York, USA, in 1918.
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