Gamma irradiation dose dependent nano-structural, optical and impedance spectroscopy of PdS thin films

Abstract

Gamma irradiation is recognized to modify the properties of thin films. In the present work, the effects of gamma irradiation on the nano-structural electrical and optical properties as of function of radiation dose has been studied. The PdS thin films deposited on glass substrate by successive ion layer adsorption and reaction (SILAR). The deposited thin films were irradiated by the gamma radiation with the 60Co for the Gamma dose range from 0 to 100 kGy. As deposited and gamma irradiated PdS thin films were investigated by impedance spectroscopy, X-ray diffraction, energy dispersive X-ray, scanning electron microscopy and Photoluminescence. The X-ray diffraction patterns exhibited a tetragonal structure of PdS thin films before after gamma irradiation, and demonstrated the changes in crystallinity, dislocation density, crystallite size and micro-strain. Field emission scanning electron microscopy and energy dispersive X-ray study conformed atomic composition of PdS thin film (1:1 ratio of Pd:S) and revealed that shape and size of grain depend on dose of gamma irradiation. Photoluminescence peak are found to be shifted to longer wavelength, intensity and width of photoluminescence peak increased for the gamma irradiated samples with increasing gamma dose. Impedance spectroscopy revealed that the enhancement of charge carrier density of irradiated PdS thin films increased linearly with gamma dose. The achieved results prove that gamma irradiation has superficial influence on nano-structural, optical and electrical properties of the deposited PdS thin films.