Structural and chemical properties of highly oriented cadmium sulfide (CdS) cauliflower films

Cadmium sulfide (CdS) films have been produced by sputter-deposition varying the sputtering-power (P) in the range of 60–120 W. The crystal structure, morphology and chemical quality of the CdS films has been investigated employing X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray spectrometry (EDS). Structural characterization indicates that all the CdS layers exhibit cauliflower morphology. Highly oriented, single phase hexagonal-CdS films can be produced at P = 75–105 W while the films at other power contain mixed phases. Characterization using XPS and EDS indicate that the CdS layers are nearly stoichiometric at P = 75–105 W, at which point S-deficiency is induced resulting in Cd-rich-CdS layers.