Optical bias effect on transient photocurrent in amorphous As2Se3: Sn films

Abstract

Optical bias effect on transient photocurrent of As2Se3: Snx (x=0¸1.0 at.%) amorphous films, excited by a monochromatic light pulse with long-wavelength of 0.63 mm was investigated. The relaxation of the photocurrent has been recorded in the wide time interval (from 0.05 up to 25 s) and was determined by capture on the deep acceptor-like traps. In a non-doped sample of a-As2Se3 the relaxation of the photocurrent weakly depends on a level of optical bias. For the samples with tin impurity, even the low levels of optical bias result in sharp reduction of the photocurrent. The experimental results are discussed in frame of the model of recombination controlled by capture on deep states.