Ni1−xPtx (x=0–0.08) films as the photocathode of dye-sensitized solar cells with high efficiency

Films of Ni 1− x Pt x ( 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 Ni 0.94 Pt 0.06 film consisted of nanoparticles with a size of 4–6 nm and a Pt loading of 5.13 μg/cm 2 . The Ni 0.94 Pt 0.06 photocathode exhibited high catalytic performance toward triiodide reduction, high light reflectance, and low charge-transfer resistance. The DSC assembled with the Ni 0.94 Pt 0.06 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 Ni 0.94 Pt 0.06 photocathode showed good stability. The results indicate that Ni 0.94 Pt 0.06 films are promising lowcost and high-performance photocathodes for use in DSCs.