Effects of Deposition Time on the Chemical Bath-deposited CuS Thin Films

Abstract

The chemical bath deposition technique was used to deposit thin films of coppersulphide onto indium tin oxide glass substrates. The bath composition included copperchloride which was the source of Cu2+ and sodium thiosulfate which supplied the S2- ions. Xraydiffraction and atomic force microscopy were used to investigate structural andmorphological characterization, respectively. The influence of deposition time was studiedto determine the optimum condition for deposition process. The deposited CuS films showedhexagonal structure. The number of peaks attributable to CuS increased as the depositiontime was increased to 16 hours based on XRD data. AFM images revealed that the chemicalbath-deposited films for 16 hours showed more homogeneous and uniform compared withother deposition times, and the highest absorbance value was obtained for the filmsdeposited at this period. The band gap energy decreased from 2.9 to 2.45 eV when thedeposition time was increased from 8 to 20 hours.Keywords: Chemical bath deposition, copper sulphide, thin films, solar cells.DOI: 10.3126/jncs.v25i0.3276Journal of Nepal Chemical Society Volume 25, 2010 pp 2-8