Abstract
The present work studies the effect of Te additions to Sb10Se90 films on the measurements of steady state "DC" and transient "AC" photoconductivity. The steady state photoconductivity was measured in temperature range 300-400 K. The spectral distribution of photocurrent was measured in the wavelength range 400-900 nm at different level of illumination and applied electric filed. The dependence of photocurrent (I-ph) on light intensity (G) follows the power low (I(ph)G(gamma)) where the exponent gamma determines the nature of the recombination process. Double beam spectrophotometer was used to measuring the film transmittance T(lambda) nm at normal incidence of Te-x(Sb10Se90)(100-x) (with x = 0%, 5%, 10% and 15%) films in the wavelength range 400-2500 nm. Based on the envelope method, the film thickness and the complex index of refraction were determined with accuracy better than 1%. Ac photoconductivity measurements revealed that, the carrier lifetime decrease with increasing relative light intensity and the applied electric filed. It was found that, the replacement of Sb and Se by Te atoms leads to the decrease in the activation energy for electrical conduction in the dark Delta E-dc and the optical band gap E-g(opt) or E-g(ph), while the refractive index and the width of localized states were found to be increases. (C) 2012 Elsevier B.V. All rights reserved.