Abstract
Experimental evidences are presented on the light-induced changes in the transport properties of amorphous As2Se3 thin films evaporated onto substrates held close to the glass-transition temperature. The transient hole-photocurrent before and after He-Ne laser irradiation has been studied as functions of temperature and applied electric field. We found that the laser irradiation increases the transit times for hole and changes the temperature dependence of dispersion parameters. These changes can be removed by annealing and accompany the photodarkening characteristic of photostructural transformation. The simulation study of transient photocurrent shows that the temperature dependence of the dispersion parameters for the irradiated films can be explained by an increase in the width of the Gaussian distribution of the gap state. We conclude that the phenomena are due to the variation in the gap-state structure arising from photostructural transformation.
