Walter Hans Schottky (German: [ˈvaltɐ ˈʃɔtki]; 23 July 1886 – 4 March 1976) was a German physicist who played a major early role in developing the theory of electron and ion emission phenomena,[2] invented the screen-grid vacuum tube in 1915 while working at Siemens,[3] co-invented the ribbon microphone and ribbon loudspeaker along with Dr. Erwin Gerlach in 1924[4] and later made many significant contributions in the areas of semiconductor devices, technical physics and technology.

His father was appointed professor of mathematics at the University of Zurich in 1882, and Schottky was born four years later.

degree in physics at the Frederick William University Berlin in 1908, and he completed his PhD in physics at this university in 1912, studying under Max Planck and Heinrich Rubens, with a thesis entitled: Zur relativtheoretischen Energetik und Dynamik, 'About Relative-Theoretical Energetics and Dynamics'.

This was also the trigger for the establishment of a semiconductor laboratory of the Siemens-Schuckert-Werke in the castle of Pretzfeld in 1946 until 1955, then he worked in Erlangen until 1958.

The idea was that a very fine ribbon suspended in a magnetic field could generate electric signals.

This led to the invention of the ribbon loudspeaker by using it in the reverse order, but it was not practical until high flux permanent magnets became available in the late 1930s.

Schottky's image PE has become a standard component in simple models of the barrier to motion, M(x), experienced by an electron on approaching a metal surface or a metal–semiconductor interface from the inside.

This leads to the following expression for the dependence of the barrier energy on distance x, measured from the "electrical surface" of the metal, into the vacuum or into the semiconductor: Here, e is the elementary positive charge, ε0 is the electric constant and εr is the relative permittivity of the second medium (=1 for vacuum).

Schottky's contributions in surface science/emission electronics and in semiconductor-device theory now form a significant and pervasive part of the background to these subjects.

In 1964 he received the Werner von Siemens Ring honoring his ground-breaking work on the physical understanding of many phenomena that led to many important technical appliances, among them tube amplifiers and semiconductors.

[7] The Frenchman Lucien Lévy had filed a claim earlier than either Armstrong or Schottky, and eventually his patent was recognized in the US and Germany.