Walter H. Schottky

Walter Hans Schottky (/ˈʃɒtki/ SHOT-kee; German: [ˈvaltɐ ˈʃɔtki]; 23 July 1886 – 4 March 1976) was a German solid-state physicist who played a major early role in developing the theory of electron and ion emission phenomena, invented the screen-grid vacuum tube in 1915 while working at Siemens, co-invented the ribbon microphone and ribbon loudspeaker along with Dr. Erwin Gerlach in 1924, and later made many significant contributions in the areas of semiconductor devices, technical physics, and technology.

The Schottky effect (a thermionic emission, important for vacuum tube technology), the Schottky diode (where the depletion layer occurring in it is called the Schottky barrier), the Schottky vacancies (or Schottky defects), the Schottky anomaly (a peak value of the heat capacity) and the Mott-Schottky equation (also Langmuir-Schottky space charge law) were named after him. He conducted research on electrical noise mechanisms (shot noise), space charge, especially in electron tubes, and the barrier layer in semiconductors, which were important for the development of copper oxide rectifiers and transistors.