Influence of substrates on the structural and optical properties of ammonia-free chemically deposited CdS films

▸ CdS thin films were deposited on different substrate. ▸ We characterized the structure and morphology of deposited CdS thin films. ▸ The band gaps of CdS thin films were determined from the absorption spectra. CdS films were deposited on glass, indium-tin-oxide (ITO)/glass and Ti foil substrates by acidic chemical bath deposition technique. Effects of substrate type on the structural and optical properties of CdS films were studied. XRD patterns indicated that the structures of CdS films on ITO/glass and Ti foil were predominantly hexagonal and the structure of CdS films on glass was a mixed cubic and hexagonal. Atomic force microscope (AFM) analysis showed that the surface of CdS films on Ti foil substrate was rougher than that of CdS films on glass and ITO/glass substrates. The average transmittances of CdS films on glass and ITO/glass were about 71% and 75%, respectively. Diffuse reflection spectra also indicated the high transmittance of CdS films on Ti foil in the longer wavelength region, but PL and Raman spectra implied that more defects existed in CdS films on Ti foil substrate.