Light-Induced Degradation of a-Si:H - A Comparison of Short-Laser-Pulse and Steady Light Degradation

Abstract

ABSTRACTAn undoped and a compensated a-Si:H sample have been degraded by 17–34 ns laser pulses and by steady light (CW) at 78K and 300K. The light-induced defect concentration N is monitored by the increase in subgap absorption a. For the same change in a pulses degrade the photoconductivity σp more than CW light and more strongly for exposures at 78K than at 300K. The lack of correlation between σp and N suggests that light soaking causes additional damage besides an increase in N. This additional effect is more pronounced for pulse and low temperature exposures.