Light Bias CPM Study of the Density of States in n-Type Amorphous Silicon.
Author: Unold, T.; Branz, H. M.; Vanecek, M.
Source: Amorphous Silicon Technology -- 1996: Proceedings of the Materials Research Society Symposium, 8-12 April 1996, San Francisco, California. Materials Research Society Symposium Proceedings, Vol. 420.
Pages/Volumes: pp. 703-708
Editor: Hack, M., et al., eds.
Publication Year: 1996
Publisher, Place: Pittsburgh, PA: Materials Research Society
Document Type: Conference Paper
Subject Code Description: Silicon Materials and Devices; Solar Energy - Photovoltaics; Amorphous Silicon
Abstract: We measure subgap absorption on n-type amorphous silicon using the "absolute" constant photocurrent method. We find that for typical monochromator probe beam intensities the measurement is not significantly influenced by lifetime changes. When the measurement is performed under light bias, an apparent increase in the defect absorption coefficient is observed, but no change in the photoexcitation threshold or spectral shape of the absorption band is seen. We show that this increase is likely due to a bias-light amplification of spectrally dependent lifetime changes. Our measurements suggest a larger electron capture cross section of positive valence band tail states compared to neutral dangling bonds.
Accession Number: 23009
Library Notes: NPL-9703 REV
Report Numbers: 23009