Characterization of CdS thin films grown by chemical bath deposition using four different cadmium sources

A comprehensive study of the effect of cadmium sources on chemical bath deposited cadmium sulfide thin films is reported. Four different cadmium sources; cadmium sulfate, cadmium chloride, cadmium iodide, and cadmium acetate have been used. The effect of cadmium sources on film optical/electrical properties as well as film thickness, composition, crystal structure, and surface morphology was studied. Film growth rate and band gap were found to be sensitive to the Cd source used. Films were found to be highly stoichiometric when cadmium chloride and cadmium iodide were used. The lowest resistivity and highest mobility and band gap obtained were in the case of cadmium sulfate. All films were found to be cubic, regardless of the Cd salt used.