Low-Cost and Extra-Simple Preparation of Porous NiS2 Counter Electrode for High-Efficiency Dye-Sensitized Solar Cells

A novel, simple, and low- cost strategy is proposed to quickly prepare nickel sulfide counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). This method only involves drop coating of the mixture of nickel chloride and thiourea on an indium tin oxide substrate, followed by low- temperature air annealing to afford an efficient nickel sulfide CE. The thus fabricated porous nickel sulfide film shows high electrical conductivity, large ionic diffusion velocity, and excellent catalytic activity. Based on it, the DSSC device manifests an impressive power conversion efficiency (PCE) of 8.94%, significantly higher than that of the platinum device (8.09%). Considering the cheap and simple fabrication, this method is very promising for CEs and can be applied to other metal sulfides for a variety of applications, such as catalysis.