Illumination-induced reversible changes in the valence band density of states of hydrogenated amorphous silicon

Abstract

Auger electron spectroscopy line shape analysis of the Si L 23 VV peak has been performed on hydrogenated amorphous silicon (a-Si:H). Significant changes in the density of states at the bottom of the valence band are observed upon light soaking the material. These changes are reversible upon in situ annealing the specimens at 150°C for two hours. The observed changes are examined for the possible existence of a localized two-hole state in the valence band spectra.