Amorphous As2Se3 films have been prepared by the thermal evaporation
technique. The variation of the photocurrent with the temperature at different
illumination intensities showed that the behavior is thermally activated with
photocurrent activation energy that increased from 0.18 to 0.3 eV as a
function of light intensity. The thermal activation energy of the dark current was
found to be 0.86 eV (about half of the band gap of As2Se3). An anomalous
behavior has been observed in the photocurrent light intensity as a function of
temperature. The photocurrent Iph changes as the light intensity Iα. For low light
intensity, 0.58 < α < 0.71 while at high light intensity the exponent α was found
to be greater than unity. On the other hand, the thermal stimulated
depolarization current (TSDC) spectrum, under dark and pre-illumination
conditions, is measured and the results were correlated with the change of the
energy configuration of the defect states in the material under investigation.