Electronic and structural changes induced by irradiation or annealing in pulsed laser deposited As50Se50 films. An XPS and UPS study

The response of amorphous As50Se50 pulsed laser deposited (PLD) films to annealing and irradiation, was investigated by X-ray and UV-photoelectron spectroscopies. It is shown that annealing smoothes out structural as well as electronic defects, while irradiation with near band-gap light enhances the film's “chemical disorder” and causes the creation of electronic defects. The observed behavior of the films is compared to that of thermally evaporated films and the corresponding bulk glasses.