Hostname: page-component-77c89778f8-m42fx Total loading time: 0 Render date: 2024-07-24T17:48:33.187Z Has data issue: false hasContentIssue false

Effect of Light-Soaking on the Density of States and Carrier Dynamics of a-Si1-xGex:H Alloys

Published online by Cambridge University Press:  21 February 2011

Thomas Unold
Affiliation:
Dept. of Physics, University of Oregon, Eugene, OR 97403
J. David Cohen
Affiliation:
Dept. of Physics, University of Oregon, Eugene, OR 97403
Charles M. Fortmann
Affiliation:
Inst. of Energy Conversion, University of Delaware, Newark, DE.
Get access

Abstract

We have used transient and steady-state junction capacitance methods to gain information about the density of states in the mobility gap of silicon-germanium alloys a-Si1-xGex:H (0.25<×<1.0). With those measurements we are also able to differentiate between minority and majority carrier processes in the alloys. We find that the (μτ)p is considerably reduced from its value in a-Si:H, even for films with small germanium concentrations (x=0.25). The density of states deduced from the optical spectra shows two distinct features above and below midgap for all concentrations, which both increase with light-soaking. Light-soaking also sharply reduces the (μτ)p.

Type
Research Article
Copyright
Copyright © Materials Research Society 1992

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. Cohen, J.D., Unold, T., Gelatos, A.V. and Fortmann, C.M., J. non-cryst. solids 141, 142154 (1992).Google Scholar
2. Unold, T., Cohen, J.D. and Fortmann, C.M., J. non-cryst. solids 137&138, 809 (1991).Google Scholar
3. For a review see Aljishi, S., Smith, Z.E. and Wagner, S., in Amorphous Silicon and Related Materials, Fritzsche, H., ed. (World Scientific, Singapore, 1989) 887.Google Scholar
4. Albright, D.E., Saxena, N., Fortmann, C.M., Rocheleau, R.E., Russell, T.W.F., AIChE Journal 36, 1555 (1990).Google Scholar
5. Cohen, J.D., in Semiconductors and Semimetals, Vol 21C, Pankove, J., ed. (Academie, New York, 1984) 1.Google Scholar
6. Michelson, C.E., Gelatos, A.V., and Cohen, J.D., Appl. Phys. Lett. 47, 397 (1985).Google Scholar
7. Cohen, J.D., Gelatos, A.V., in Amorphous Silicon and Related Materials, Fritzsche, H., ed. (World Scientific, 1989) 475.Google Scholar
8. Gelatos, A.V., Mahavadi, K.K., Cohen, J.D. and Harbison, J.P., Appl. Phys. Lett. 53, 403 (1988).Google Scholar
9. Crandall, R.S. and Balberg, I., Appl. Phys. Lett. 58, 508 (1991)Google Scholar
10. Chen, L., Taue, J., Lee, J.K., and Schiff, E.A., Phys. Rev. B 43, 11694 (1991).Google Scholar
11. Paul, W., in Amorphous Silicon and Related Materials, Fritzsche, H., ed. (World Scientific, 1989) 63.Google Scholar