Photoconductivity in Thin Film of a-(Ge₂₀Se₈₀)_0.90Sn_0.10

Abstract

Steady state and transient photoconductivity measurements have been done on thin film of a-(Ge₂₀Se₈₀)_0.90Sn_0.10 as a function of temperature and intensity. Dark conductivity (σ_d) and photoconductivity ($\sigma_{\rm ph}$) measurements show that the conduction in this glass is through an activated process having single activation energy in the temperature range 283–350 K. The intensity dependence of steady state photoconductivity ($\sigma_{\rm ph}$) follows a power law with intensity (F), $\sigma_{\rm ph} \propto F^{\gamma}$, where the power γ has been found between 0.5 and 1.0, suggesting bimolecular recombination. Rise and decay of photocurrent at different temperatures and intensities show that photocurrent (I_ph) rises monotonically to the steady state value and the decay of photocurrent is quite slow. A detailed analysis of photoconductive decay shows that the recombination within localized states may be predominant recombination mechanism in this glassy alloy.