Photoluminescence from optically induced metastable states in a-As 2S 3

Abstract

A new photoluminescence (PL) band was observed in a-As 2S 3, which grows at low temperature with band-gap irradiation, that is, irradiation with light whose energy is around band gap energy. It is annealed out at room temperature. The PL centers are associated with As atoms. The decay of the PL has two components, a slow decay component and a fast decay component. The temperature dependence of the life time of the slow decay component can be explained by thermal activation from a triplet level (corresponding to the slow decay component) to a single level (corresponding to the fast decay component).