PHOTOINDUCED CHANGES IN GLOW-DISCHARGE-DEPOSITED AMORPHOUS SILICON - STAEBLER-WRONSKI EFFECT

The dramatic photo-induced changes in the electrical properties of glow- discharge-deposited amorphous silicon observed recently by Staebler and Wronski (1977) are discussed in the light of a model recently proposed by the author for defect states in this material. It is assumed that self-trapped excitons in the form of close pairs of oppositely charged defect centres are produced after irradiation with band-gap light. The Fermi level position is then moved nearer the mid-gap, accounting for the metastable decrease in d.c. conductivity, provided the samples are not heavily doped. © 1979 Taylor & Francis Ltd.