Synthesis and characterization of Cd_(1?x)Zn_xS nanopowder and its nanostructured thin films

摘要

Cd_(1?x)Zn_xS (with x = 0, 0.01, 0.03, 0.05 and 0.1) nanopowder were synthesized by chemical precipitation method under N_2 atmosphere at room temperature. Cd_(1?x)Zn_xS nanostructured thin films were deposited on the glass at 450 ?C by spraying the colloidal suspension of the Cd_(1?x)Zn_xS nanoparticles. Optical and structural properties of both nanostructures were investigated. The prominent peaks of X-ray diffractions (XRD) of samples indicate that the Cd_(1?x)Zn_xS crystalline grain size in the nanostructured thin film is larger than the Cd_(1?x)Zn_xS nanoparticles in the nanopowder, due to growing of the grains, originated from high temperature of the substrate. UV-Vis absorption spectra show that both Cd_(1?x)Zn_xS nanostructures have smaller band edge wavelength in comparison with bulk samples. There is also an increase in blue shift value of the band gap of both Cd_(1?x)Zn_xS nanostructures, with increasing x, which can be attributed to Burstein-Moss effect. It was found that the variation of the band gap of ZnxCd1?xS nanopowder and nanostructured thin films with Zn concentration are approximately linear with similar slopes. Photoluminescence (PL) spectra indicated that the emission peaks of both the samples are shifted toward the shorter wavelengths with increasing Zn~(+2) ions.