Photoelectrochemical investigation on spray deposited n-CdIn2S4 thin films

Abstract

Polycrystalline thin films of n-CdIn2S4 have been spray deposited onto amorphous and fluorine-doped tin oxide (FTO) coated glass substrates at the optimized substrate temperature of 380 °C. The films were characterized by X-ray diffraction (XRD) and optical absorption studies. XRD studies revealed that the films were polycrystalline with spinel cubic structure. The optical absorption studies showed the band gap energy to be 2.14 eV. Photoelectrochemical (PEC) investigations were carried out using cell configuration n-CdIn2S4/1 M NaOH+1 M Na2S+1 M S/C. Using Butler model, the optical band gap and minority carrier diffusion length (LP) were found to be 2.22 eV and 0.07 μm, respectively. Gartner's model was used to calculate the minority carrier diffusion length and the donor concentration (ND) for CdIn2S4 films at three different wavelengths. ND was found to be of the order of 1016 cm-3.