Photoemission from AlGaAs/GaAs Heterojunctions and Quantum Wells under Negative Electron Affinity Conditions

  • Franco Ciccacci
Part of the NATO ASI Series book series (NSSB, volume 206)


The possibility of lowering the work function Φ in several materials by adsorption of alkali metals has been extensively used in the pioneer works on photoemission, making it possible to perform experiments with conventional light sources. This procedure has proved to be very effective in semiconductors, leading to the development of Negative Electron Affinity (NEA) photocathodes 1. Under such conditions, the bottom of the bulk conduction band lies above the potential barrier at the surface, so that electrons excited to the conduction band can escape into vacuum. In practice NEA condition is achieved in heavily p-doped semiconductors (to encourage downward band bending at the surface) by adding in Ultra High Vacuum (UHV) environment a thin film (one to some atomic layers) of cesium rich oxide on the clean semiconductor surface. The activation procedure, developed for technological purposes, is well known, at least for gallium arsenide, and NEA GaAs photocathodes are widely used in photomultiplier tubes.


Quantum Yield Conduction Band Photon Energy Molecular Beam Epitaxy Quantum Well 
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  1. 1.
    W.E. Spicer, Apol. Phys. 12 115 (1977), and references therein.Google Scholar
  2. 2.
    G. Lampel, in Proceeding of the 12th International Conference on the Physics of Semiconductors, Stuttgart 1974, ed. by M.H. Pilkuhn ( Teubner, Stuttgart 1974 ) p. 743.Google Scholar
  3. 3.
    D.T. Pierce, R.J. Celotta, G.C. Wang, W.N. Unertl, A. Galejs, C.E. Kuyatt, and S.R. Mielczarek, Rev. Sci. Instrum. 51, 478 (1980).ADSCrossRefGoogle Scholar
  4. 4.
    H.J. Drouhin, C. Hermann, and G. Lampel, Phys, Rev. B 31, 3859 (1985).ADSCrossRefGoogle Scholar
  5. 5.
    H.J. Drouhin, C. Hermann, and G. Lampel, Phys. Rev. B 31, 3872 (1985).ADSCrossRefGoogle Scholar
  6. 6.
    S.F. Alvarado, F. Ciccacci, S. Valeri, M. Campagna, R. Feder, and H. Pleyer, Z. Phys.B 44, 259 (1981).ADSCrossRefGoogle Scholar
  7. 7.
    F. Ciccacci, S.F. Alvarado, and S. Valeri, J. Apnl. Phys. 53, 4395 (1982).ADSCrossRefGoogle Scholar
  8. 8.
    F. Ciccacci, H.J. Drouhin, C. Hermann, R. Houdré, and G. Lampel, Appl. Phys, Lett.5A, 632 (1989).Google Scholar
  9. 9.
    R.C. Miller, D.A. Kleinmann, and A.C. Gossard, in Proceedings of the 16th International Conference on the Physics of Semiconductors, Edingburgh 1978, ed. by B.L.H. Wilson ( Institute of Physics, London 1979 ) p. 1043.Google Scholar
  10. 10.
    S.F. Alvarado, F. Ciccacci, and M. Campagna, Appl. Phys. Lett. 39, 615 (1981).ADSCrossRefGoogle Scholar
  11. 11.
    R. Houdré, C. Hermann, G. Lampel, P.M. Frijlink, and A.C. Gossard, Phys. Rev, Lett 55, 734 (1985).ADSCrossRefGoogle Scholar
  12. 12.
    F. Ciccacci, H.J. Drouhin, C. Hermann, R. Houdré, and G. Lampel, Vuoto XVI, 185 (1986).Google Scholar
  13. 13.
    R. Houdré, C. Hermann, G. Lampel, and A.C. Gossard, Physica Scripta T 13, 241 (1986).ADSCrossRefGoogle Scholar
  14. 14.
    F. Ciccacci, H.J. Drouhin, C. Hermann, R. Houdré, G. Lampel, and F. Alexandre, in Excitons in Confined Systems, Springer Proceedings in Physics 25, ed. by R. Del Sole, A. D’Andrea, and A. Lapiccirella ( Springer-Verlag, Berlin 1988 ) p. 185.CrossRefGoogle Scholar
  15. 15.
    F. Ciccacci, H.J. Drouhin, C. Hermann, R. Houdré, G. Lampel, and F. Alexandre, Solid State Electron. 31, 489 (1988).ADSCrossRefGoogle Scholar
  16. 16.
    For the band parameters of the A1GaAs alloy, see S. Adachi, J. Appl. Phys. 58, R1 (1985).CrossRefGoogle Scholar
  17. 17.
    H.J. Drouhin, and M.Eminyan, Rev. Sci. Instrum. 57, 1052 (1986).ADSCrossRefGoogle Scholar
  18. 18.
    F. Meier and B.P. Zakharchenya (ed.’s), Optical Orientation, Series Modern Problems in Solid State Sciences, Vol. 8 ( Elsevier, Amsterdam 1984 ).Google Scholar
  19. 19.
    M.I. D’yakonov and V.I. Perel’, Sov. Phys, JEPT 33 1053 (1971) Zh. Eksp. Teor. Fiz. LQ, 1954 (1971)].Google Scholar
  20. 20.
    G. Fishman and G. Lampel, Phys. Rev. B 16, 820 (1977).ADSCrossRefGoogle Scholar
  21. 21.
    D.T. Pierce, F. Meier, and P. Zuercher, Appl. Phys. Lett. 26, 670 (1975).ADSCrossRefGoogle Scholar
  22. 22.
    J. Kessler, Polarized Electrons, Springer Series on Atoms and Plasma 1 ( Springer Verlag, Berlin 1985 ).CrossRefGoogle Scholar
  23. 23.
    R. Feder (ed.), Polarized Electrons in Surface Physics, Advances Series in Surface Science (World Scientific, Singapore 1985 ).Google Scholar
  24. 24.
    C. Sinclair, in High Energy Physics with Polarized Beams and Polarized Targets, ed. by C. Joseph and J. Soffer ( Birkhauser Verlag, Lausanne 1981 ) p. 27.Google Scholar
  25. 25.
    P. Zorabedian, SLAC Report 248 (Standford University, 1982 ).Google Scholar
  26. 26.
    S.F. Alvarado, F. Ciccacci, H. Riechen, and M. Campagna, unpublished.Google Scholar
  27. 27.
    N.E. Christensen, E. Molinari, and G. Bachelet, Solid State Commun.56, 125 (1985).Google Scholar
  28. 28.
    F. Ciccacci, E. Molinari, and N.E. Christensen, Solid State Commun. 62, 1 (1987).ADSCrossRefGoogle Scholar
  29. 29.
    D. Conrath, T. Heindroeff, A. Hermanni, N. Ludwig, and E. Reichert, Appt. Phys. 20, 1955 (1979).Google Scholar

Copyright information

© Springer Science+Business Media New York 1989

Authors and Affiliations

  • Franco Ciccacci
    • 1
  1. 1.Istituto di FisicaPolitecnico di MilanoMilanoItaly

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