Photoconductivity and high-field conduction studies in amorphous this films of Se80-x Te20 Sbx

Abstract

The present paper reports the temperature dependence of dark- and photo-conductivities in vacuum-evaporated thin films ofa-Se80-xTe20Sbx with a view to see the effect of Sb addition to the binary Se80Te20 system. The results indicate that the photoconductivity (σph) increases along with the dark conductivity (σd) after the addition of Sb to the binary Se80Te20 system. The relative photosensitivity, however, decreases upon Sb addition. The results are explained in terms of the charged defect states. Current-voltage characteristics have also been studied and the results indicate that the dark current becomes super Ohmic at higher fields 104V/cm. An analysis of the experimental data indicates that a Poole-Frenkel— type conduction may be responsible for the observed behaviour.