Study of y-rays Enhanced Changes of the ZnO:Al Thin Film Structure and Optical Properties

Abstract

In this work thin film samples of 300 nm thickness with composition ZnAlO were deposited on glass substrate by DC sputtering technique. The effect of the atmosphere gas contents during sputtering was studied by using Ar for some of the prepared samples and Ar+O2 mixture for the others. Additional investigations were also done for the effect of the heat treatment of the samples for comparison with gamma irradiation. The samples were irradiated by three gradual gamma rays doses using 60Co source. The x-ray diffraction patterns showed that the deposited films were of amorphous structure and converted partially to crystalline form by irradiation. Optical properties of the investigated samples were measured using UV-vis spectrometer. The transmission spectra of irradiated samples were compared with that of unirradiated ones for comparison. In general, it was found that the optical parameters of the samples showed decrease in the transmittance after irradiation and the calculated optical energy gap was decreased. On the other hand, the heat treatment of the samples increased the energy gap. The data were analyzed and discussed in the light of gamma rays interaction with the investigated thin films.