Hopping conduction in zinc vanadate semiconducting glasses

Abstract

In this paper, we have studied the electrical conductivity for different compositions of the zinc vanadate semiconducting glasses within a wide temperature range. We have analyzed the temperature dependence of the electrical conductivity within the framework of various models for the hopping conduction. We have observed that Mott's phonon-assisted nearest neighbor hopping model of small polarons is appropriate for describing the conductivity data at high temperatures. We have further observed that at lower temperatures, Mott's variable range hopping model is operative, while Greaves' variable range hopping model is valid within the intermediate temperature range. The values of the density of states at the Fermi level, which are obtained from the analysis, are consistent with those for localized states.