Structural and Optical Studies on Cr-Doped ZnS Nanoparticles Prepared by Flat Co-precipitation Method

Abstract

Intrinsic and chromium (Cr) doped zinc sulfide (ZnS) nanoparticles (NPs) have been synthesized by the co-precipitation method. The X-ray diffraction (XRD) studies reveals that the nanoparticles are crystalline in nature with cubic phase that have the (111) as preferential orientation. Even though the Cr ions have ionic radii greater than Zn, no significant modification in the crystal structure occurs as revealed by the XRD pattern. The doping induces a reduction in the peak intensities. The optical energy band gap values decrease and the Urbach exponential tail width increases with an increase in Cr level. When the dopant concentration is increased, the microstrain decreases and crystallite size increases. The surface morphology analysis has been carried out using scanning electron microscopy (SEM). The presence of the elements Zn, S, and Cr has been conformed using energy-dispersive X-ray spectroscopy (EDAX). The intensity that corresponds to Cr lines increases as the dopant increases with respect to Zn which is an evidence of the increased Cr level.