Surface States and Rectification at a Metal Semi-Conductor Contact

  • John Bardeen
Part of the Perspectives in Condensed Matter Physics book series (PCMP, volume 4)

Abstract

Localized states (Tamm levels), having energies distributed in the “forbidden” range between the filled band and the conduction band, may exist at the surface of a semi-conductor. A condition of no net charge on the surface atoms may correspond to a partial filling of these states. If the density of surface levels is sufficiently high, there will be an appreciable double layer at the free surface of a semi-conductor formed from a net charge from electrons in surface states and a space charge of opposite sign, similar to that at a rectifying junction, extending into the semi-conductor. This double layer tends to make the work function independent of the height of the level in the interior (which in turn depends on impurity content). If contact is made with a metal, the difference in work function between metal semi-conductor is compensated by surface states charge, rather than by a space charge as is independent of the metal. Rectification characteristics are then independent of the metal. These ideas are used to explain results of Meyerhof and others on the relation between contact potential differences and rectification.

Keywords

Fermi Level Double Layer Surface State Space Charge Work Function 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Editoriale Jaca Book spa 1999

Authors and Affiliations

  • John Bardeen
    • 1
  1. 1.Bell Telephone LaboratoriesMurray HillUSA

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