Distribution of gap states in a-As2Se3

Abstract
A series of pure bulk a-As2Se3 samples has been examined by means of steady-state and transient photoconductivity techniques as well as by photoinduced absorption in order to clarify the requirements to be met by a model for the distribution of gap states in this material. Some sources of metastable defects, which probably distorted earlier measurements, are identified. The distribution required is found to be broad and featureless but must allow for a set of discrete excitation energies. A model by Klinger and Karpov involving elastically soft lattice configurations best satisfies these conditions.