Persistent Photoconductivity, the Staebler-Wronski Effect, and Long-Range Disorder in a-Si:H

Abstract

ABSTRACTWe report measurements of the conductivity, thermopower, and conductance fluctuations before and after light exposure for a-Si:H samples that show either persistent photoconductivity (PPC) or a Staebler-Wronski effect. Both the conductivity and thermopower are changed by light exposure, but no change is observed in the difference between the conductivity and thermopower activation energies for any of the samples studied here. This suggests that the long-range disorder is unaffected by light exposure. For some samples, the magnitude or statistical properties of the conductance fluctuations are affected by light exposure. We compare these results to previous studies of the Staebler-Wronski effect and discuss their implications for models of the light-induced changes and the 1/f noise in a-Si:H.