CHARACTERIZATION OF CHEMICALLY DEPOSITED CADMIUM SULFIDE THIN FILMS

Cadmium sulfide (CAS) thin films have been deposited on glass/conducting glass substrates using low-cost chemical bath deposition method. The deposited films have been characterized using various techniques in order to optimize growth parameters. It has been confirmed by X-ray diffraction measurement that the deposited layers are mainly consisting of CdS phase. The PEC measurements indicate that the deposited CdS layer is n-type in electrical conduction, and optical absorbance measurements show that the band gap is 2.42 eV for as-deposited film and 2.27 eV upon heat treatment for one hour in air ambient. Both atomic force microscopy and scanning electron microscopy measurements indicate the formation of pinhole free and smooth surface of CdS films of nanosized grains. The electrical resistivity is also observed in the order of 104(4) Omega cm and decreases as temperature increases.