Effect of bias illumination on photoinduced absorption decay in ?-Si:H

Zeldov and Weiser1 proposed a model to explain the influence of optical biasing on the decay of photoinduced absorption (PA) in ?-Si:H at high temperatures observed by Pfost, Vardeny, and Tauc.2 This model differs from the model originally used2 for interpreting the experimental data at temperatures higher than 80 K by neglecting carrier trapping at neutral dangling-bond sites in the material. As a result, the quasi-Fermi level set by the bias illumination will reside in the conduction-band tail ("bias-saturated band tail").