Deep Impurity Levels in Semiconductors, Semiconductor Alloys, and Superlattices

  • John D. Dow
  • Shang Yuan Ren
  • Jun Shen
Part of the NATO ASI Series book series (NSSB, volume 183)


Impurity levels determine the electrical properties of semiconductors and often strongly influence the optical properties as well. Until rather recently it was widely believed that “shallow impurities,” namely those impurities that produce energy levels within ≃0.1 eV of a band edge, were well understood in terms of hydrogenic effective-mass theory [1]. However “deep impurities” were regarded as more mysterious, having levels more than 0.1 eV deep in the gap; and several theoretical attempts were made to understand why their binding energies were so large. While specific deep levels were explained rather well by the early theories, most notably the pioneering work of Lannoo and Lenglart on the deep level in the gap associated with the vacancy in Si [2], numerous attempts to explain why the binding energy of a particular level might be large (making the level deep), rather than small, continued until recently, when it was realized that this basic picture of impurity levels was incomplete [3,4].


Alloy Composition Deep Level Band Edge Shallow Level Valence Band Maximum 


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Copyright information

© Plenum Press, New York 1988

Authors and Affiliations

  • John D. Dow
    • 1
  • Shang Yuan Ren
    • 1
  • Jun Shen
    • 1
  1. 1.Department of PhysicsUniversity of Notre DameNotre DameUSA

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