Thin films of cadmium sulfide (CdS) have been prepared on ITO substrates by chemical bath deposition (CBD) technique using cadmium chloride (CdCl₂), or cadmium sulfate (CdSO₄) as cadmium ions source and thiourea as sulphur ions source. In a previous paper [1], we proposed the preparation of CdS layers deposited by chemical bath deposition using cadmium chloride (CdCl₂) for CIS and CIGS thin film solar cells. Our goal is to provide a comprehensive study on the effect on film thickness, grain size, crystal structure and surface morphology. The growth was mainly controlled by the ion-by-ion growth mechanism, or by cluster-by-cluster mechanism. Various properties of the films, such as optical transmission, surface morphology and the X-ray diffraction patterns were studied. The scanning electron microscope results revealed that the morphology of the CdS was homogeneous. The X-ray diffraction results showed the film structure was a mixture of two phases: hexagonal and cubic. Optical transmission measurements have been done at room temperature with unpolarized light at normal incidence in the wavelength range from 300nm to 900nm.

CdS thin film, chemical-bath-deposited method, CIGS solar cell, morphology, structural properties, optical properties.