Radiative transitions between exciton sub-bands in semiconductors

  • G. K. Vlasov


It is shown both theoretically and experimentally, that radiative Auger-recombination of excitons and impact excitation of excitons by hot excitons or electrons in direct-gap semiconductors at appropriate conditions lead to inverse population of exciton and bi-exciton subbands and, consequently, to stimulated submillimeter (far infrared) radiation. In CdS crystals, excited by nitrogen laser at temperatures from 1.4–4.2 K to 300 K, a stimulated submillimeter radiation on exciton transitions was observed. At T=1.4–4.2 K a few milliwatts of total output in 50–120 mkm spectral interval was obtained by Hg- lamp excitation. The strong correlation between phenomena taken place in visible and submillimeter regions was established. Our data permit to obtain the most fulfil picture of exciton and bi-exciton energy spectrum and to explain the structure of P-band in luminescence spectra.

Key words

semiconductors excitons far-infrared radiation inverse population 


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  1. 1.
    E.M. Gershenzon et al. Pys'ma v ZETP.18, 160 (1973).Google Scholar
  2. 2.
    T. Timuck, H. Navarro, N.O. Lippari, M. Altarelly, Solid State Commun.25, 217 (1978).Google Scholar
  3. 3.
    M. Kobayashi, S. Narita. In Physics of Highly Excited States in Solids. Ed by M. Ueta and Y. Nishina. Springer, New York (1976), p. 295.Google Scholar
  4. 4.
    G.K. Vlasov, M.S. Brodin, A.V. Krytskii. Phys. Stat. Sol. (b),71, 787 (1975).Google Scholar
  5. 5.
    G.K. Vlasov, S.G. Kalenkov, G.A. Kupchenko. Physica Tverdogo Tela,20, 1886 (1978).Google Scholar
  6. 6.
    V.G. Lysenko, V.I. Revenko, Physica Tverdogo Tela,20, 2147 (1978).Google Scholar
  7. 7.
    L.V. Keldysh, A.N. Kozlov. ZETP,54, 978 (1968).Google Scholar
  8. 8.
    E. Hanamura. J. Phys. Soc. Japan,29, 50 (1970).Google Scholar
  9. 9.
    A.S. Davydov, Quantum Mechanics (in Russian). Mir, Moskow (1973).Google Scholar
  10. 10.
    L.M. Kanskaya et al. Physica i Technica Poluprovodnikov,13, 2424 (1979).Google Scholar
  11. 11.
    K.A. Aristova, C. Trallero Giner, I.G. Lang, and S.T. Pavlov, Phys. Stat. Sol. (b),85, 351 (1978).Google Scholar
  12. 12.
    G.A. Boiko et al., Phys. Stat. Sol. (b),85, 111 (1978).Google Scholar
  13. 13.
    H. Büttner, Phys. Stat. Sol.,42, 775 (1970).Google Scholar
  14. 14.
    G.K. Vlasov. In Proceedings of Second International Conf. on Infrared Physics, Zurich (1979).Google Scholar
  15. 15.
    G.K. Vlasov. In Digest of Techn. Papers of Fourth International Conference on Infrared and Near- mm Waves, Miami (1979).Google Scholar
  16. 16.
    J.J. Hopfield and D.G. Thomas. Phys. Rev.,122, 35 (1961).Google Scholar

Copyright information

© Plenum Publishing Corporation 1981

Authors and Affiliations

  • G. K. Vlasov
    • 1
  1. 1.Institute of PhysicsAcademy of Sciences of the Ukrainian SSRKievU.S.S.R.

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