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Thermal and Optical Stretched Exponentials in Defect Kinetics in a-Si:H

Published online by Cambridge University Press:  01 January 1993

David Redfield
Affiliation:
Stanford University, Department of Materials Science and Engineering, Stanford, CA 94305
Richard Bube
Affiliation:
Stanford University, Department of Materials Science and Engineering, Stanford, CA 94305
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Abstract

Dispersive description of defect generation in a-Si:H that leads to stretched-exponential transients is extended by relaxing the assumption that light-induced processes and thermally induced processes have the same dispersive character. This is done by separating the rate equation for the defect density into two parts, one thermal and one optical, each with its own dispersion parameter. The solutions of this new equation — which must be obtained numerically — generally have two distinct parts: there may be a two-part rise or a peak, depending on the relative values of the two stretch parameters. Using this formulation we have readily simulated the recently observed peak in relaxation of a previously heavily degraded solar cell while exposed to a weak light. We find no way to explain other reports in similar two-part experiments that relaxation is faster under weak excitation than without.

Type
Research Article
Copyright
Copyright © Materials Research Society 1993

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References

REFERENCES

1. Redfield, D., Appl. Phys. Lett. 54, 398 (1989).Google Scholar
2. Redfield, D. and Bube, R. H., Appl. Phys. Lett. 54, 1037 (1989).Google Scholar
3. Bube, R. H. and Redfield, D., J. Appl. Phys. 66, 820 (1989).Google Scholar
4. Bube, R. H.. Echeverria, L. and Redfield, D., Appl. Phys. Lett. 57, 79 (1990).Google Scholar
5. Redfield, D. and Bube, R. H., in Amorphous Silicon Technology - 1991, Ed. by Madan, A., (Mater. Res. Soc. Symp. Proc. 219, Pittsburgh, PA 1991) p. 21.Google Scholar
6. Chen, L. and Yang, L., J. Non-Cryst. Solids 137&138, 1185 (1991).Google Scholar
7. Luft, W.,in Proc. 22nd IEEE Photovoltaic Specialists Conf.,(IEEE, New York, 1991) p. 1393.Google Scholar
8. Redfield, D., in Amorphous Silicon Technology - 1992, Ed. by Thompson, M., (Mater. Res. Symp. Soc. Proc. 258, Pittsburgh, PA 1992) p. 341.Google Scholar
9. Yang, L. and Chen, L., (in proceedings of this symposium).Google Scholar
10. Xu, X., (in proceedings of this symposium).Google Scholar
11. Street, R., Appl. Phys. Lett. 59, 1084 (1991).Google Scholar
12. Gleskova, H., (in proceedings of this symposium).Google Scholar
13. Redfield, D., Appl. Phys. Lett. 49, 1517 (1986).Google Scholar
14.See, for example, Kimmerling, L., Solid State Elec. 297, 1391 (1978).Google Scholar
15. Redfield, D., Appl. Phys. Lett. 48, 846 (1986).Google Scholar