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 copper
sulphide onto indium tin oxide glass substrates. The bath composition included copper
chloride which was the source of Cu²⁺ and sodium thiosulfate which supplied the S^2- ions. Xray
diffraction and atomic force microscopy were used to investigate structural and
morphological characterization, respectively. The influence of deposition time was studied
to determine the optimum condition for deposition process. The deposited CuS films showed
hexagonal structure. The number of peaks attributable to CuS increased as the deposition
time was increased to 16 hours based on XRD data. AFM images revealed that the chemical
bath-deposited films for 16 hours showed more homogeneous and uniform compared with
other deposition times, and the highest absorbance value was obtained for the films
deposited at this period. The band gap energy decreased from 2.9 to 2.45 eV when the
deposition time was increased from 8 to 20 hours.

Keywords: Chemical bath deposition, copper sulphide, thin films, solar cells.

DOI: 10.3126/jncs.v25i0.3276

Journal of Nepal Chemical Society Volume 25, 2010 pp 2-8