Ni1-xPtx (x=0-0.08) Films as the Photocathode of Dye-Sensitized Solar Cells with High Efficiency

Films of Ni1-xPtx (x = 0, 0.02, 0.04, 0.06, and 0.08) have been prepared on fluorine-doped tin oxide-coated (FTO) glass substrates by a chemical plating method and used as the photocathode for dye-sensitized solar cells (DSCs). The Ni0.94Pt0.06 film consisted of nanoparticles with a size of 4-6 nm and a Pt loading of 5.13 mu g/cm(2). The Ni0.94Pt0.06 photocathode exhibited high catalytic performance toward triiodide reduction, high light reflectance, and low charge-transfer resistance. The DSC assembled with the Ni0.94Pt0.06 photocathode gave a short-circuit photocurrent density (J(sc)) of 16.79 mA/cm(2), an open-circuit photovoltage (V-oc) of 736 mV, and a fill factor (FF) of 66.4%, corresponding to an overall conversion efficiency of 8.21% under standard AM 1.5 irradiation (100 mW/cm(2)), which is higher than that for the DSC with a pure Pt photocathode obtained by conventional thermal decomposition. Furthermore, the DSC based on the Ni0.94Pt0.06 photocathode showed good stability. The results indicate that Ni0.94Pt0.06 films are promising low-cost and high-performance photocathodes for use in DSCs.