The influence of cadmium ions source on the morphology, structural and optical properties of CdS thin films

Abstract

[EN] 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.