Pulse electrodeposition and solid phase voltammetry of copper indium disulfide semiconductor thin films

CuInS2 thin films were deposited onto fluorine doped tin oxide coated glass (FTO) using pulse electrodeposition from aqueous solutions comprising Cu-EDTA, In2(SO4)3 and Na2S2O3. Deposited films were polycrystalline with tetragonal structure and behavior as a p-type semiconductor. A smooth and adherent film was obtained at pulse height of -1.00 V and the band gap energy was found to be 1.40 eV with indirect transition. The Cu:In:S compositions of the films was 1.1:1.0:1.8. From morphological studies, the particles had worm like structure which interconnected with each other. Solid phase voltammetry resulted in redox couple of Cu2+/Cu+ and Cu+/Cu0