Cadmium sulfide (CdS) films have been formed using an ultrasonic spray pyrolysis method. These films annealed at a temperature range of 200-500oC in air for 5 hours. The effects of annealing on the vibrational, structural, optical and morphological properties of cadmium sulfide films were looked at using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, UV-visible spectroscopy(UV–vis) and atomic force microscopy (AFM). The X-ray diffraction data showed that the films had settled along (100) direction with a hexagonal wurtzite type structure. It was found that grain size goes up with an increase in the annealing temperature. The optical band gap numbers of the CdS film at different annealing temperatures were calculated and were found to be in the range of 2.40-2.44 eV. Raman results showed two rises attributed to the 1LO (300cm-1) and 2LO (601cm-1) modes of hexagonal CdS. The chemical bonding was studied by FTIR spectra. The saturation rises in the FTIR spectra of the films located at 550–715 and 844–1160 cm-1 can be given to the Cd–S and C–O phonon modes, respectively. The AFM of all the films were determined. These images colors changed with the annealing temperature.
Annealed CdS film, XRD; Raman; Optical properties