Effect of the Ph on Crystal Structural, Optical and Surface Morphological Properties of the Cds Films Deposited By Chemical Bath Deposition

Abstract

Cadmium sulphide films have been deposited from aqueous solutions onto the glass substrates by chemical bath deposition method at different pH values (10.30, 10.35, 10.40, 10.45 and 10.50) at 80 degrees C. The crystal structure and the size of the crystallites in the film were characterized from X-ray diffraction patterns. XRD pattern of the films showed cubic phase with preferred (111) orientation and the grain sizes were calculated between 31-107 nm. The thicknesses of the CdS films were determined to be between 85-200 nm. The band gap of the films was obtained from the absorbance measurements in the visible range. The optical absorption studies reveal that the transition is direct with band gap energy values between 2.33 and 2.39 eV. The transmission efficiency of CdS films were exhibit about between 50%-65% in the visible region. The surface morphology of the films was characterized by atomic force microscopy and field emission scanning electron microscope. The deep energy level is estimated about 0.6 eV below the conduction band.