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Band Offsets at Semiconductor Heterojunctions: Bulk or Interface Properties?

  • Stefano Baroni
  • Raffaele Resta
  • Alfonso Baldereschi
Part of the NATO ASI Series book series (NSSB, volume 189)

Abstract

The problem of whether band offsets at semiconductor interfaces are determined by bulk properties of the constituents or substantially affected by interface phenomena is critically readdressed. In particular, the conditions under which band offsets do not depend on the interface orientation are examined. State-of-the-art ab-initio pseudopotential calculations are performed for (GaAs)3(AlAs)3 grown in the (001), (110), and (111) directions. Our results are analysed through a novel definition of the interface charge distribution which does not snake any use of ideal reference interfaces: the dipole corresponding to such a distribution directly yields the potential drop across the interface. Our calculations give for the (001), (110), and (111) interfaces a band offset of 0.49, 0.51, and 0.49 eV respectively, thus indicating that orientation independence holds in this case. However, in the case of the (111) orientation, two inequivalent interfaces exist whose offsets slightly differ (0.07 eV); associated with this difference we also found a net interfacial charge accumulation at the two inequivalent interfaces (±2.8 ×10−4 electrons per unit surface cell). Our results are finally interpreted through a new model based on crystal symmetry and whose only ingredients are the bulk charge densities of the the two constituents. The model — though not reproducing the fine details of the (111) superlattice — is in excellent agreement with our first-principles results and with available experimental data.

Keywords

Bulk Region Band Offset Semiconductor Interface Simple Cubic Interface Orientation 
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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References

  1. [1]
    R.S. Bauer and G. Margaritondo, Phys. Today, 40, 27 (1987) and ref. quoted therein. See also the issues: J. Vac Sci. and Technol. B 4 No. 4 (1986), and B 5, No. 4 (1987).Google Scholar
  2. [2]
    For a review of models of semiconductor heterjunction interfaces, see R.S. Bauer and G. Margaritondo, Ref. 1.Google Scholar
  3. [3]
    C. Van de Walle and R.M. Martin, in Computer-Based Microscopic Description of the Structure and Properties of Materials, edited by J. Broughton, W. Krakow and S.T. Pantelides, (Materials Research Society, Pittsburg, 1986), p. 21; J. Vac. Sci. Technol. B 4, 1056; Phys. Rev. B 35, 8154 (1987).Google Scholar
  4. [4]
    M. Cardona and N.E. Christensen, Phys. Rev. B 35, 6182 (1987); N.E. Christensen, preprintGoogle Scholar
  5. [5]
    D.M. Bylander and L. Kleinman, Phys. Rev. B 34, 5280 (1986); ibid. 36, 3229 (1987); Phys. Rev. Lett. 59, 2091 (1987).Google Scholar
  6. [6]
    S. Massidda, B.I. Min and A.J. Freeman, Phys. Rev. B 35, 9871 (1987).ADSCrossRefGoogle Scholar
  7. [7]
    S. Baroni, P. Giannozzi, and A. Testa, Phys. Rev. Lett. 58, 1861 (1987).ADSCrossRefGoogle Scholar
  8. [8]
    G.B. Bachelet, D.R. Hamann and M. Schlüter, Phys. Rev. B 26, 4199 (1982).ADSCrossRefGoogle Scholar
  9. [9]
    D.M. Ceperley and B.J. Alder, Phys. Rev. Lett. 45, 566 (1980)ADSCrossRefGoogle Scholar
  10. J. Perdew and A. Zunger, Phys. Rev. B 23, 5048 (1981).ADSCrossRefGoogle Scholar
  11. [10]
    H.J. Monkhorst and J.P. Pack, Phys. Rev. B 13, 5188 (1976).MathSciNetADSCrossRefGoogle Scholar
  12. [11]
    R.W. Godby, M. Schlüter and L.J. Sham, Phys. Rev. B 35, 4170 (1987); ibid. 36, 6497 (1987).Google Scholar
  13. [12]
    S.B. Zhang, D. Tomanek, and S.G. Louie, preprintGoogle Scholar
  14. [13]
    L. Kleinman, Phys. Rev. B 24, 7412 (1981).CrossRefGoogle Scholar
  15. [14]
    A. Munoz, J. Sânchez-Dehesa and F. Flores, Phys. Rev. B 35, 6468 (1987).ADSCrossRefGoogle Scholar
  16. [15]
    M. Peressi, A. Baldereschi, S. Baroni, and R. Resta, to be published.Google Scholar
  17. [16]
    C.K. Shih and W.E. Spicer, Phys. Rev. Lett. 58, 2594 (1987).ADSCrossRefGoogle Scholar
  18. [17]
    S.P. Kowalczyk, J.T. Cheung, E.A. Kraut, and R.W. Grant, Phys. Rev. Lett. 56, 1605, (1986)ADSCrossRefGoogle Scholar
  19. T.M. Duc, H. Hsu, and J.P. Fannie, Phys. Rev. Lett. 58 1127, (1987).ADSCrossRefGoogle Scholar
  20. [18]
    S.H. Wei and A. Zunger, Phys. Rev. Lett. 59, 144 (1987).ADSCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1989

Authors and Affiliations

  • Stefano Baroni
    • 1
  • Raffaele Resta
    • 1
  • Alfonso Baldereschi
    • 2
    • 3
  1. 1.Scuola Internazionale Superiore di Studi AvanzatiTriesteItaly
  2. 2.Dipartimento di Fisica TeoricaUniversità di TriesteTriesteItaly
  3. 3.Institut de Physique AppliquéeEcole Polytechnique Fédérale de LausanneLausanneSwitzerland

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