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Change in The Spectral Shape of the Subgap Absorption in a-SI:H by Photodegradation at 4.2K and its Relation to the Mobility-Lifetime Product

Published online by Cambridge University Press:  15 February 2011

P. Stradins
Affiliation:
James Franck Institute, University of Chicago, Chicago IL
H. Fritzsche
Affiliation:
Tucson, AZ
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Abstract

We have observed a pronounced change in the shape of subgap absorption spectrum α(hν) of a-Si:H due to photodegradation at T=4.2K, in contrast to light exposure at T=300K. During the 4.2K exposure, α(hν) at 1.1≤(h‥)≤1.6eV increases with time as (α(t)-α(0)) ∝t0.3. However, for hν≤1eV the absorption α(hν) stays constant or decreases with exposure at 4.2K. Subsequent anneal causes the subgap absorption at the higher photon energies to decrease monotonically while a (hν ≤ 1.1 eV) increases first and goes through a maximum at T≈350K. This unexpected increase in a(hν) during annealing occurs at the anneal temperatures where the degraded mobility-lifetime product recovers. We suggest that the nonmonotonic recovery of a (hν≤ 1.1eV) during annealing is associated with preferential anneal of deeper defects or with structural relaxations around the defects during anneal causing a shift in their energy levels.

Type
Research Article
Copyright
Copyright © Materials Research Society 1997

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References

REFERENCES

1. Tran, M., Fritzsche, H., Stradine, P., Mat. Res. Soc. Symp. Proc. 297, 195 (1993).Google Scholar
2. Stradins, P., Fritzsche, H., Phil. Mag. B69, 121 (1994).Google Scholar
3. Wang, Q., Zhu, J., Xie, C., Tao, W., Zhang, X., Bai, G., Phil. Mag. B61, 437 (1990).Google Scholar
4. Zhang, Q., Kumeda, M., Shimizu, T., Jpn. J. Appl. Phys. 32, L371 (1993).Google Scholar
5. Tzanetakis, P., Kopidakis, N., Androulidaki, M., Kalpouzos, C., Stradins, P., Fritzsche, H., J. Non-Cryst. Solids 198–200, 458 (1996).Google Scholar
6. Han, D., Fritzsche, H., J. Non-Cryst. Solids 59&60, 397 (1983).Google Scholar
7. Shepard, K., Smith, Z.E., Aljishi, S., Wagner, S., Appl. Phys. Lett. 53, 1644 (1988).Google Scholar
8. Hattori, K., Fukuda, S., Nishimura, K., Okamoto, H., Hamakawa, Y., J. Non-Cryst. Solids 164–166, 351 (1993).Google Scholar
9. Platz, P., Bruggemann, R., Bauer, G. H., J. Non-Cryst. Solids 164–166, 355 (1993)Google Scholar
10. Conte, G., Irrera, F., Nobile, G., Palma, F., J. Non-Cryst. Solids 164–166, 419 (1993).Google Scholar
11. Stiebig, H., Siebke, F., Carius, R., Mat. Res. Soc. Symp. Proc. 420, 715 (1996).Google Scholar
12. Mettler, A., Wyrsch, N., Shah, A., J. Non-Cryst. Solids 164–166, 427 (1993).Google Scholar
13. Shklovskii, B. I., Fritzsche, H., Baranovskii, S. D., J. Non-Cryst. Solids 114, 325 (1989).Google Scholar
14. Stradins, P., Fritzsche, H., Tran, M., Mat. Res. Soc. Symp. Proc. 377, 467 (1995).Google Scholar
15. Stradins, P., Fritzsche, H., J. Non-Cryst. Solids 198–200, 432 (1996).Google Scholar
16. Ganguly, G., Matsuda, A., J. Non-Cryst. Solids 164–166, 31 (1993).Google Scholar
17. Fritzsche, H., Yoon, B.-G., Chi, D.-Z., Tran, M. Q., J. Non-Cryst. Solids 141, 123 (1991).Google Scholar
18. Heck, S., Stradins, P., Fritzsche, H., Mat. Res. Soc. Symp. Proc. 377, 485 (1995).Google Scholar
19. Dersch, H., Schweitzer, L., Phil. Mag. B50, 397 (1984).Google Scholar
20. Fritzsche, H., Mat. Res. Soc. Symp., this volume.Google Scholar