Structural, morphological and optical properties of sprayed nanocrystalline thin films of Cd1-xZnxS solid solution

A series of nanocrystalline thin films of cadmium zinc sulphide (Cd1-xZnxS) solid solution were deposited on glass substrates using spray pyrolysis. Cadmium chloride (CdCl2), zinc chloride (ZnCl2) and thiourea (NH2CSNH2) were used as the sources of Cd, Zn and S respectively. The films were characterized using structural, morphological and optical techniques. X-ray diffraction (XRD) studies show that the films of Cd1-xZnxS are polycrystalline and single phase having the wurtzite structure. The crystallites in the thin films of pure CdS possess preferred crystallographic orientation along the <002> direction. The preferred orientation of crystallites in the Cd1-xZnxS films changes from <002> to <101> with increase in Zn concentration. The lattice parameters of Cd1-xZnxS decrease with increase in Zn concentration. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies show that the surfaces of the films are smooth and are uniformly covered with nanoparticles. Energy dispersive analysis of xrays (EDAX) results reveal that the grown films have good stoichiometry. Optical transmission spectra confirm the good quality of the Cd1-xZnxS films.