Temperature-dependent structural, morphological and optical properties of chemical bath-deposited CdS films

Cadmium sulfide (CdS) films were grown on top of the fluorine-doped tin oxide (FTO) coated glass substrates at four different bath temperatures by chemical bath deposition (CBD) technique. X-ray diffraction (XRD), ultraviolet–visible (UV–Vis) spectrometry, energy-dispersive X-ray spectroscopy (EDX), field emission scanning electron microscope (FESEM), photoluminescence (PL) and Fourier-transform infrared (FTIR) analyses were employed to examine the morphological and optical properties of deposited films. XRD studies confirmed the cubic crystalline nature of the deposited films which improved with increase in deposition temperature, and EDX along with FESEM study showed that the films were smooth and uniform with appropriate chemical composition. Band-gap values of the CBD CdS films calculated by UV–Vis spectrometry were found to be in the range of 2.32–2.39 eV. A strong blue band and a weak green band were observed in PL emission spectra. C–S, Cd-S and S–C–N vibrations were found by FTIR spectral analysis.