Dependence of the hopping-conductivity exponent on band shape for two-dimensional impurity bands

Abstract
The temperature dependence of the conductivity exponent s p is evaluated for half-filled two-dimensional impurity bands. For rectangular, triangular and Gaussian band shapes the activation energy at intermediate temperatures is 0·33, 0·4 and 0·48n s/ρF, respectively, where n s is the density of sites and ρF is the peak density of states.