EFFECTS OF EXCESSIVE REACTANTS ON THE PROPERTIES OF CADMIUM SULFIDE THIN FILMS PREPARED BY CHEMICAL BATH DEPOSITION

摘要

Cadmium sulfide nanoparticles were synthesized and grown on glass substrates by chemical bath deposition. The method involves the preparation of aqueous solutions containing cadmium chloride (CdCl{sub}2) and thiourea [CS(NH{sub}2){sub}2] as source materials for cadmium and sulfur components, respectively. Ammonium hydroxide (NH{sub}4OH)-ammonium chloride (NH{sub}4Cl) solution was used as a complexing agent in this study. The hexagonal and cubic crystal structure of as-deposited CdS films, determined by X-ray diffraction (XRD), is shown. The effects of Cd:S ratio variation on the surface morphology and optical properties of CdS films are also reported. The UV-vis transmission spectrum and SEM micrographs indicated that the Cd:S ratio in the aqueous solution had an impact on the band gap as well as the crystallite size and packing density of the CdS particles due to the quantum confinement effect.