Effect of deposition time on copper incorporation of ZnS thin films by low-cost technique

Abstract

The copper-doped zinc sulphide (CuZnS) thin films were prepared by low-cost chemical bath deposition (CBD). The deposited films were varied by copper doping concentration and preparation time. The structural, optical, and electrical properties of the films were analyzed. The XRD patterns of the films exhibit polycrystalline nature with a prominent peak in the (111) plane. The improvement of the crystallinity was observed in the variation of deposition time. The lattice constant of the CuZnS films slightly deviates from that of pure ZnS. The deposited films have shown uniform substrate coverage without pinholes. EDAX results confirmed the presence of copper, zinc, and sulphur in the deposited films. The absorbance was found to be high in the ultraviolet region. The bandgap of the films obtained was 3.7 eV and marginally reduced with deposition time. The Urbach energy of the CuZnS films varied with deposition time. The PL study confirms the incorporation of copper and band edge emission. The electrical properties of the films were investigated by Hall effect measurement.