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Femtosecond Far-Infrared Studies of Photoconductivity in a-Si:H and a-SiGe:H

Published online by Cambridge University Press:  21 March 2011

A. V. V. Nampoothiri  and
S. L. Dexheimer
A. V. V. Nampoothiri
Affiliation:
Department of Physics, Washington State University, Pullman, WA 99164-2814
S. L. Dexheimer
Affiliation:
Department of Physics, Washington State University, Pullman, WA 99164-2814
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Abstract

We present femtosecond time-resolved studies of the frequency-dependent photoconductivity in the far-infrared spectral range (∼ 1 – 10 meV) in PECVD a-SiGe:H and a-Si:H thin films. The experiments are carried out using an optical pump / terahertz (THz) probe technique, in which a femtosecond pump pulse excites carriers into the extended states and a time-delayed probe pulse measures the resulting change in the far-infrared optical properties, which are directly related to the ac photoconductivity, as the carrier distribution evolves in time. We find that the frequency-dependent conductivity measured on picosecond time scales shows a strongly non-Drude behavior, with components of the response fitting to a power-law frequency dependence, reflecting processes associated with localized states.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 808: Symposium A – Amorphous and Nanocrystaline Silicon Science and Technology-2004 , 2004 , A5.9
Copyright
Copyright © Materials Research Society 2004

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References

REFERENCES

1. Nampoothiri, A.V.V., Nelson, B.P., and Dexheimer, S.L., Mat. Res. Soc. Symp. Proc. 762, 333 (2003).Google Scholar
2. Wu, Q. and Zhang, X.-C., Appl. Phys. Lett. 71, 1285 (1997).Google Scholar
3. Beard, M.C., Turner, G.M. and Schmuttenmaer, C.A., Phys. Rev. B 62, 15764 (2000).Google Scholar
4. Beard, M.C., Turner, G.M. and Schmuttenmaer, C.A., J. Appl. Phys. 90, 5915 (2001).Google Scholar
5. Dexheimer, S.L., Zhang, C.P., Liu, J., Young, J.E. and Nelson, B.P., Mat. Res. Soc. Symp. Proc. 715, A2.1 (2002)Google Scholar
6.T.-I. Jeon and Grischkowsky, D., Phys. Rev. Lett. 78, 1106 (1997).Google Scholar
7. Mott, N.F. and Davis, E.A., Electronic processes in non-crystalline materials, (Oxford University Press, 1979).Google Scholar