Preparation and characterization of spray deposited NiMoO4 thin films for photovoltaic electrochemical studies

The preparation of nickel molybdate (NiMoO4) thin film by spray pyrolysis with ammonical solution as a precursor is presented. The phase and surface morphology characterizations have been carried out by XRD and SEM analysis. The study of optical absorption spectrum in the wavelength range 350–850 nm shows direct as well as indirect optical transitions in the thin film material. The dc electrical conductivity measurements in the temperature range 310–500 K indicate semiconducting behavior of the thin film with high resistivity (107 Ω cm) at room temperature. The thin films deposited on fluorine doped tin oxide (FTO) coated conducting glass substrates were used as a photoanode in photovoltaic electrochemical (PVEC) cell with configuration: NiMoO4 |Ce4+, Ce3+| Pt; 0.1 M in 0.1N H2SO4. The PVEC characterization reveals the fill factor and power conversion efficiency to be 0.48 and 0.81%, respectively. The flat band potential is found to be −0.39 V (SCE).