On the frequency dependence of conductivity in amorphous solids

Abstract

The literature on experiments on a.c. conductivity in various disordered semiconductors is briefly summarized. A theory of the a.c. conductivity, suitable for hopping conduction in the pseudogap of amorphous semiconductors, is developed, and expressions applicable under various conditions are derived. Comparing some of the results with available experimental data, the concentration of localized states in the pseudogap of several materials is estimated.