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Energy Differences Between the Si and the Ge Dangling Bond Defects in a-Si1-xGex Alloys

Published online by Cambridge University Press:  21 February 2011

S.M. Cho ,
B.N. Davidson  and
G. Lucovsky
S.M. Cho
Affiliation:
Department of Physics, and Materials Science and Engineering, North Carolina State University, Raleigh, N.C. 27695–8202
B.N. Davidson
Affiliation:
Department of Physics, and Materials Science and Engineering, North Carolina State University, Raleigh, N.C. 27695–8202
G. Lucovsky
Affiliation:
Department of Physics, and Materials Science and Engineering, North Carolina State University, Raleigh, N.C. 27695–8202
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Abstract

We have investigated the difference in the electronic energies of neutral Si and Ge dangling bond states in undoped a-Si1-xGex alloys as a function of the alloy composition, x, and local bond-angle distortions. The local density of states, LDOS, in a-Si1-xGex alloys has been calculated using nearest-neighbor interactions, and employing the Cluster Bethe Lattice method. We conclude that for ideal, tetrahedrally bonded amorphous semiconductors alloys, the Ge dangling bond energy is lower than that of Si dangling bonds by ∼ 0.13 eV, independent of the specific nearest neighbors to the dangling bond (3 Si-atoms, 2 Si-atoms and 1 Ge-atom, etc.), but that the spread in dangling bond energies associated bond-angle variations of the order of 6–8 degrees can be larger than this energy difference (∼0.3 eV or greater). This means that structural disorder, rather than chemical disorder causes Si and Ge-atom dangling bond states to overlap in their energy distributions.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 258: Symposium A – Amorphous Silicon Technology – 1992 , 1992 , 583
Copyright
Copyright © Materials Research Society 1992

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References

REFERENCES

1. Chevallier, J., Wieder, H., Onton, A. and Guarnìeri, C.R., Solid-State Comm. 26, 867 (1977).Google Scholar
2. Hauschild, D., Fischer, R., Fuhs, W., Phys. Stat. Sol.(b) 102, 563 (1980).Google Scholar
3. Mackenzie, K.D., Eggert, J.R., Leopold, D.J., Li, Y.M., Lin, S., Paul, W., Phys Rev. B31, 2198 (1985).Google Scholar
4. Marfaing, Y., Proc. 2nd E. C. Photovoltaic Solar Energy Conf., Berlin, 23–26 April 1979, ed. Reidel, D. (Dordrecht, 1979) p. 287.Google Scholar
5. Lin, S.Y., Lucovsky, G. and Pollard, W.B., J. Non-Cryst. Solids 66, 291 (1984).Google Scholar
6. Finger, F., Fuhs, W., Beck, G., Carius, R., J. Non-Cryst. Solids 97/98, 1015 (1987).CrossRefGoogle Scholar
7. Street, R.A., Tsai, C.C., Stutzmann, M., Kakalios, J., Phil. Mag. B, 56, 289 (1987).Google Scholar
8. Joannopoulos, J.D. and Yndurain, F., Phys. Rev. B. 10, 5164 (1974).Google Scholar
9. Vogl, P., Hjalmarson, H. P. and Dow, J. D., J. Phys. Chem. Solids 44, 56 (1983).Google Scholar
10. Harrison, W.A.. Electronic Structure and the Properties of Solids. (W.H. Freeman and Co., 1980).Google Scholar
11. Christensen, N.E., Satpathy, S., and Pawlowska, Z., Phys. Rev. B, 36, 1032 (1987).Google Scholar
12. Tersoti, J., Phys. Rev. B. 30, 4874 (1984).Google Scholar
13. Lucovsky, G. and Lin, S.Y., AIP Conf. Proc. 120, 55 (1984).Google Scholar
14. Pickett, W.E., Louie, S.G. and Cohen, M.L., Phys Rev. B17, 815 (1978).Google Scholar
15. Harrison, W.A., J. Vac. Sci. Technol. 14, 1016 (1977).Google Scholar
16. Fedders, P.A. and Carlsson, A.E. Phys. Rev. B, 32, 1134 (1989).Google Scholar
17. Matsuura, H., J. Appl. Phys. 64, 1964 (1988).CrossRefGoogle Scholar
18. Unold, T., Cohen, J.D., J. Non-Crystalline Solids 137&138, 809 (1991).Google Scholar
19. Froyen, S., Wood, D.M., and Zunger, A., Phys Rev. B, 37, 6893 (1988).Google Scholar
20. Van de Walle, C.G. and Martin, R.M., Phys. Rev. B. 34, 5621 (1986)Google Scholar