Physical Investigation of Au8+ Ions Irradiated CdSe/FTO Thin Films

Thin films of cadmium selenide (CdSe) have been electrodeposited on Fluorine doped tin oxide (FTO) coated glass substrate in an electrolyte containing Cd(CH3COO)2.2H2O and SeO2 at pH 2.7 and temperature 300 K. The as-deposited films were irradiated using Au8+ ions with energy of 100 MeV at fluencies of 1 x 1011 and 1 x 1012 ions/cm2 using tandem pelletron accelerator. The irradiation-induced modifications in CdSe thin films were studied using structural, optical and electrical X-ray diffraction (XRD), scanning electron microscopy (SEM), optical band gap, and I-V characteristics. XRD analysis revealed that the as-deposited films were polycrystalline in nature with cubic phase. After irradiating the films with Au8+ ions metastable cubic phase transformed into stable polycrystalline hexagonal phase. An enhancement in grain size, decrease in band gap energy and decrease in resistivity of the film after irradiation was seen from SEM micrographs, optical analysis, and I-V characteristics, respectively.