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Optical and Electronic Properties of GaAs/AlAs Random Superlattices

Published online by Cambridge University Press:  22 February 2011

E.G. Wang
Affiliation:
Space Vacuum Epitaxy Center, University of Houston, Houston, TX 77204
J.H. Xu
Affiliation:
Texas Center for Superconductivity and Department of Physics, University of Houston, Houston, TX 77204
W.P. Su
Affiliation:
Space Vacuum Epitaxy Center, University of Houston, Houston, TX 77204 Texas Center for Superconductivity and Department of Physics, University of Houston, Houston, TX 77204
C.S. Ting
Affiliation:
Texas Center for Superconductivity and Department of Physics, University of Houston, Houston, TX 77204
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Abstract

The optical and electronic properties of three-dimensional (3D) random GaAs/AlAs superlattices (SLs) has been studied by using a tight-binding Hamiltonian with secondneighbor interactions. We calculate three completely disordered sequences with the probability of GaAs layers being 30%, 50%, and 70%. The higher the GaAs composition, the narrower the indirect gap. An energy-level crossing is found at the bottom of conduction band, which originates from the M-state splitting induced by layer disorder. The localized states over two - four monolayers play an important role in the absorption edge of random SL. The highest absorption intensity of the band-edge transitions in our random models is about eight times stronger than that of short period ordered GaAs/AlAs SL. Our results are in good agreement with some recent photoluminescence measurements.

Type
Research Article
Copyright
Copyright © Materials Research Society 1994

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References

[1] Chomette, A., Devesud, B., Regreny, A., and Bastard, G., Phys. Rev. Lett. 57, 1464 (1986).CrossRefGoogle Scholar
[2] Yamamoto, T., Kasu, M., Noda, S., and Sasaki, A., J. Appl. Phys. 68, 5318 (1990).CrossRefGoogle Scholar
[3] Strozier, J., Zhang, Y. A. Horton, C., Ignatiev, A., and Shih, H. D. Appl. Phys. Lett. 62, 3426(1993);W. P. Su and H. D. Shih J. Appl. Phys. 72, 2080 (1992).CrossRefGoogle Scholar
[4] Wang, E. G. Xu, J. H. Su, W. P. and Ting, C. S. Appl. Phys. Lett. 63, 1411 (1993).CrossRefGoogle Scholar
[5] Vogl, P., Hjalmarson, H. P. and Dow, J. D. J. Phys. Chem. Solids 44, 365 (1983).CrossRefGoogle Scholar
[6] Yamaguchi, E., J. Phys. Soc. Jpn. 56, 2835 (1987).CrossRefGoogle Scholar
[7] Newman, K. E. and Dow, J. D. Phys. Rev. B30, 1929 (1984).CrossRefGoogle Scholar
[8] Ge, Weikun, Sturge, M. D. Schmidt, W. D. Pfeiffer, L. N. and West, K. W. Appl. Phys. Lett. 57, 55 (1990).CrossRefGoogle Scholar
[9] Chang, Y. C. and Schulman, J. N. Phys. Rev. B31, 2069 (1985).CrossRefGoogle Scholar
[10] Xu, Zhizhong, Solid State Com. 75, 1143 (1990).CrossRefGoogle Scholar