Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-25T15:27:47.242Z Has data issue: false hasContentIssue false
  • English
  • Français

Light-Induced Metastable Defects or Light-Induced Metastable H Atoms in a-Si:H Films?

Published online by Cambridge University Press:  15 February 2011

C. Godet
C. Godet*
Affiliation:
Laboratoire de Physique des Interfaces et des Couches Minces (UPR 0258 CNRS) Ecole Polytechnique, 91128 Palaiseau-Cedex (France), [email protected]
Get access

Abstract

In hydrogenated amorphous silicon (a-Si:H) films, the increase of the metastable defect density under high-intensity illumination is usually described by an empirical two-parameter stretched-exponential time dependence (characteristic time τSE and dispersion parameter β). In this study, a clearly different (one-parameter) analytic function is obtained from a microscopic model based on the formation of metastable H (MSH) atoms in a-Si:H films. Assuming that MSH atoms are the only mobile species, only three chemical reactions are significant : MSH are produced from doubly hydrogenated (SiH HSi) configurations and trapped either at broken bonds or Si-H bonds, corresponding respectively to light-induced annealing (LIA) and light-induced creation (LIC) of defects. Competition between trapping sites results in a saturation of N(t) at a steady-state value Nss. A one-parameter fit of this analytical function to experimental data is generally good, indicating that the use of a statistical distribution of trap energies is not necessary.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 467: Symposium A – Amorphous and Microcrystalline Silicon Technology - 1997 , 1997 , 79
Copyright
Copyright © Materials Research Society 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Stutzmann, M., Phil. Mag. B 56, 63 (1987).Google Scholar
2. Wu, Z.Y., Siéfert, J.M. and Equer, B., J. Non-Cryst. Solids 137&138, 227 (1991).Google Scholar
3. Meaudre, R. and Meaudre, M., Phys. Rev. B 45, 12134 (1992).Google Scholar
4. Graeff, C.F.O., Buhleier, R. and Stutzmann, M., Appl. Phys. Lett. 62, 3001 (1993).Google Scholar
5. Street, R., Physica B 170, 69 (1991).Google Scholar
6. Darwich, R., Roca, P. Cabarrocas, i, Vallon, S., Ossikovski, R., Morin, P. and Zellama, K., Phil. Mag. B 72, 363 (1995).Google Scholar
7. Godet, C., Morin, P. and Roca, P. Cabarrocas, i, J. Non-Cryst. Solids 198–200, 449 (1996).Google Scholar
8. Godet, C. and Roca, P. Cabarrocas, i, J. Appl. Phys. 80, 97 (1996).Google Scholar
9. Roca, P. Cabarrocas, i, Chévrier, J.B., Hue, J., Lloret, A., Parey, J.Y. and Schmitt, J.P.M., J. Vac. Sci. Technol. A9, 2331 (1991).Google Scholar
10. Godet, C. and Roca, P. Cabarrocas, i, Mat. Res. Soc. Vol. 420, 647 (1996).Google Scholar
11. Morin, P. and Roca, P. Cabarrocas, i, Mat. Res. Soc. Vol. 336, 281 (1994).Google Scholar
12. Morin, P., Godet, C., Equer, B. and Roca, P. Cabarrocas, i, 12th E.C. Photovoltaic Solar Energy Conference Proceedings, editors Hill, R., Palz, W. and Helm, P., Stephens and Associates (Bedford UK, 1994), p. 687.Google Scholar
13. Isomura, M., Hata, N. and Wagner, S., J. Non-Cryst. 137&138, 223 (1991).Google Scholar
14. Van de Walle, C.G., Phys. Rev. B 53, 1 (1996).Google Scholar