Gamma irradiation induced modifications in spin coated CdSe thin films

Semiconducting nanomaterials of II-VI groups are attractive candidates for various optoelectronic applications in engineering and research due to their size dependent properties. In the present investigations, cadmium selenide nanoparticles synthesised by solvothermal route were dispersed as a thin film on glass substrate via spin coating technique. The properties of thin films exposed to 50, 100 and 150 kGy doses of gamma rays from Co-60 source were characterized by XRD, SEM, EDX, UV-spectrophotometer and PL-spectrophotometer. XRD analysis confirmed the change in orientation of planes after gamma exposure. The optical studies revealed decrease in band gap from 2.17 to 2.00 eV and hence an increase in the conductivity of thin films after irradiation. The increased structural disorder and/or defects induced due to gamma irradiation might be responsible for the variation in optical band gap.