Effects of deposition time on the properties of chemical bath deposited CdS films

Chemical bath deposition(CBD) of CdS semiconductor thin films in solutions of cadmium acetate are carried out.The effects of deposition time on the properties of CdS thin films were investigated.Deposition time was varied from 14min to 30min.The properties of the CdS thin films with different deposition time have been studied by XRD,XRF,SEM and Optical transmittance spectra.It revealed that the structure of CdS thin film which deposited with 14min is the mixture of hexagonal and cubic crystal.As increasing of the deposition time,the structure of CdS films was transformed to cubic and the S/Cd ration increased as the films are Cd rich.Scanning electron microscopy studies of the CdS thin films deposited by this method showed that the films were continuous,homogeneous and with high compactness.But with increasing of deposition time, there were many white particles on the surface of CdS thin films.The deposition time has greatly influenced the optical properties and the band gap of CdS thin films.