The radiation effect on optical and morphological properties of Ag–As–Te thin films

Abstract The effect of gamma irradiation on the features of Ag x As 50 - x Te 50 with 3 ⩽ x ⩽ 20 films has been studied. The studies indicated that the films partially transform from the amorphous phase to a crystalline phase at low doses of gamma irradiation ( 0.5 – 3 kGy ) . The radiation effect on the optical spectrum of Ag–As–Te films has been studied on the deposited films before and after each radiation dose. It is found that the calculated optical band gap ( E g ) decreases with increasing Ag content and at the same time decreases with the radiation dose up to 3 kGy. Increasing the radiation dose up to 3 kGy induces an indirect transition and consequently decreases the energy gap. This behavior is associated with the generation of excess electronic localized states. The surface morphology has been investigated with a scanning electron microscope (SEM).