A Study of the Time Scales of Processes Responsible for the Light-induced Degradation of a-Si:H by Pulse Illumination

Abstract

ABSTRACTDegradation properties of a-Si:H and a-Si:D by pairs of intense light pulse pairs are examined. By varying the delay time between pulses in a pair while keeping the total illumination time and dose constant, the time scales involved in the light-induced defect creation are investigated. In nanosecond pulse case, we find a sharp drop in degradation efficiency with delay time, followed by further gradual decrease at much longer times. For microsecond pulses, the degradation efficiency varies with the delay time in microseconds. The recombination proceeds bimolecularly and is largely completed during the pulse. It is suggested that the first stage of degradation is related to bimolecular recombination that takes place during the pulse. The second stage is possibly related to longer-living metastable species.