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Study of a-Si:H Using the Solid/Electrolyte System

Published online by Cambridge University Press:  01 January 1993

Y. Goldstein
Affiliation:
Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel.
A. Many
Affiliation:
Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel.
S.Z. Weisz
Affiliation:
Department of Physics, University of Puerto Rico, Rio Piedras, PR 00931.
J. Penalbert
Affiliation:
Department of Physics, University of Puerto Rico, Rio Piedras, PR 00931.
W. Munoz
Affiliation:
Department of Physics, University of Puerto Rico, Rio Piedras, PR 00931.
M. Gomez
Affiliation:
Department of Physics, University of Puerto Rico, Rio Piedras, PR 00931.
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Abstract

Pulsed measurements on the solid-electrolyte system, which proved very useful in the study of crystalline semiconductors, have been found to be equally effective when applied to hydrogenated amorphous Si films. Here, as well, the aSi:H/electrolyte interface is essentially blocking to current flow and, as a result, surface space-charge layers, ranging from large depletion to very strong accumulation conditions, can be induced and studied. In particular, valuable information can be gained on the density of the localized bulk states. Measurements in the depletion range under illumination yield directly the total density of occupied states in the entire energy gap. This is very useful in obtaining a quick and reliable assessment of the quality of the amorphous films. In high-grade films we find that the total density of occupied states is around 1018 cm−3. The data in the accumulation range, on the other hand, provide useful information on unoccupied states near the conduction band edge. The blocking nature of the amorphous Si/electrolyte interface is utilized also to apply a sweep-out technique for an accurate determination of μτ the product of the electron mobility and lifetime, even when this value is very low. In a rather poor-quality film, for example, we find μτ to be 5 × 10−8 cm2/V.

Type
Research Article
Copyright
Copyright © Materials Research Society 1993

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References

REFERENCES

1.See, for example, Madan, A. and Shaw, M.P., The Physics and Applications of Amorphous Semiconductors (Academic, Boston, 1988) and Amorphous Silicon Technology-1992 Edited by Thompson, M.J., Hamakawa, Y., LeComber, P.G., Madan, A. and Schiff, E., Mat. Res. Soc. Symp. Proc. 258 (1992).Google Scholar
2. Trokman, S., Many, A., Goldstein, Y., Heiland, G., Kohl, D. and Moormann, H., J. Phys. Chem. Solids 42, 937 (1981).Google Scholar
3. Wolovelsky, M., Levy, J., Goldstein, Y., Many, A., Weisz, S.Z. and Resto, O., Surf. Sci. 171, 442 (1986).Google Scholar
4. Weisz, S.Z., Penalbert, J., Many, A., Trokman, S. and Goldstein, Y., J. Phys. Chem. Solids, 51, 1067 (1990).Google Scholar
5. Many, A., Goldstein, Y. and Grover, N.B.,Semiconductor Surfaces (North Holland, Amsterdam, 1970).Google Scholar
6. Goldie, D., LeComber, P.G. and Spears, W.E., Mat. Res. Soc. Symp. Proc. 119, 489 (1988).Google Scholar
7. Schiff, E.A. and Silver, M. in Amorphous Silicon and Related Materials , Fritzsche, H., Ed. (World Scientific, Singapoore, 1988), p. 825.Google Scholar
8. Tiedje, T. and Rose, A., Solid State Commun. 37, 48 (1981).Google Scholar