Electrical properties of semiconducting amorphous copper-tellurite glasses

Abstract

The temperature dependence of the electrical properties of the semiconducting amorphous copper-tellurite glasses is presented in a range of compositions. A polaronic model is shown to be generally applicable, and the variation of activation energy with the glass composition is found to dominate the conductivity. In particular, a strong pre-exponential factor containing a term exp(-2 alpha R), arising from electron tunnelling, is not observed. The results suggest that the theory of small polaron hopping in the adiabatic approximation may be most appropriate in the present system. In the intermediate temperature range, Greaves' variable range hopping analysis seems applicable. The glass forming oxide is shown to affect the activation energy for hopping conduction.