Photoelectromagnetic effect

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The photo-electromagnetic effect (PEM effect), also known as the photomagnetoelectric effect (PME effect) or Kikoin-Noskov effect , is a physical phenomenon in semiconductors . It describes the generation of an electrical voltage by incident light (→ photo conduction ), perpendicular to a magnetic field .

The photoelectric effect must be distinguished from it .

history

The effect was first observed in 1934 by Isaak Konstantinowitsch Kikoin and MM Noskov on copper (I) oxide . The first correct explanation for this effect was given by Jakow Ilyich Frenkel that same year . 1956 followed a precise theory by Willy W. van Roosbroeck .

description

The PEM effect can be described as a kind of Hall effect with an optically induced current. Light falls on a semiconductor material; the internal photoelectric effect generates free electrons and defect electrons in the conduction or valence band of the semiconductor. Due to the strong absorption , this occurs mainly in an area close to the surface, and a concentration gradient of free charge carriers is formed in the direction of the depth . This gradient causes charge carrier diffusion into the depth of the semiconductor (see also the Dember effect ). A magnetic field applied perpendicular to the plane of incidence of the light causes a force ( Lorentz force ) on the moving charge carriers perpendicular to the direction of the magnetic field and movement. The deflection occurs due to the opposite charge for electrons and holes in opposite directions. The result is a charge separation and an electrical voltage on the sides of the semiconductor.

application

The PEM effect is used, among other things, to determine the characteristic properties of semiconductor materials or to detect electromagnetic radiation .

literature

  • Marian Nowak: Photoelectromagnetic effect in semiconductors and its applications . Pergamon Press, 1987.

Individual evidence

  1. ↑ IK Kikoin, MM Noskov: A new photoelectric effect in cuprous oxide. Part I. In: Physics. Z. Soviet Union . tape 586-596 , no. 5 , 1934.
  2. ↑ Jakow Ilyich Frenkel: Physics. Z. Soviet Union . No. 5 , 1934, pp. 597 .
  3. ↑ Jakow Ilyich Frenkel: Physics. Z. Soviet Union . No. 8 , 1935, pp. 185 .
  4. ^ W. van Roosbroeck: Theory of the Photomagnetoelectric Effect in Semiconductors . In: Physical Review . tape 101 , no. 6 , February 15, 1956, p. 1713-1725 , doi : 10.1103 / PhysRev.101.1713 .
  5. ↑ D. Geozow: Photo-Electromagnetic Effect . In: Manfred von Ardenne (ed.): Effects of physics and their applications . Harri Deutsch Verlag, 2005, ISBN 978-3-8171-1682-9 , pp. 456 .