Effect of deposition time on optical properties of nanocrystalline CdS thin films synthesized via rf- sputtering technique

Nanocrystallites of cadmium sulfide (CdS) thin films have been deposited by radio frequency magnetron sputtering technique. XRD and TEM diffraction patterns have confirmed the nanocrystalline cubic CdS phase formation. The intensity of XRD peaks also increases with the increase of deposition time that implies that better crystallinity takes place at higher deposition time. TEM micrographs of the films have revealed the manifestation of nano CdS phase with average particle size lying in the range 2.00 nm to 5.36 nm. UV-VIS spectrophotometric measurement showed high transparency of the film with a blue-shift of the absorption edge. The direct optical bandgap values of the films increased with the increase of deposition time and lie in the range from 3.06 - 3.94 eV.