Transient Photoconductivity in Amorphous Se-Ge-Ag System

Abstract

Transient Photoconductivity measurements have been made in vacuum evaporated thin films of Se0.80 - xGe0.20Agx at different intensities, temperatures and illumination times. The films exhibit long-lived residual photoconductivity, called persistent photoconductivity, with an extremely slow decay rate. The persistent photoconductivity (PPC) increases with an increase in intensity and illumination time. However, this quantity decreases with increase in temperature. These results indicate that the decay of photoconductivity is not only governed by the carrier trapped in the intrinsic defects but also gets affected by the light induced defect creation through structural changes The persistent photoconductivity effect is found to be suppressed on increase of Ag concentration in a- Se0.80 - xGe0.20Agx, which may be understood in terms of smaller effect of light induced defects due to higher concentration of inherent structural defects in dark at higher concentration of Ag.