On the measurement of densities of states in amorphous semiconductors

Abstract

In many analyses of experimental results on amorphous semiconductors, it is assumed that the only important transitions from localized states are those to extended states above the mobility edge. However, for states sufficiently far below this edge, hopping transitions between localized states become more probable than transitions to extended states. The temperature-dependence of the critical energy E_o(T) at which this occurs is examined, and is calculated for a simple model.