Vertically aligned Ni3Se2 arrays with dendritic-like structure as efficient counter electrode of dye-sensitized solar cells

Fabrication of low-cost counter electrodes with high electrocatalytic performance is one of the most important challenges for dye-sensitized solar cells. Vertically aligned Ni3Se2 arrays with dendritic-like structure have been synthesized by a simple solvothermal method in this paper. Due to direct electron transfer and more catalytic active sites, Ni3Se2 arrays can be used as counter electrodes of dye-sensitized solar cells. The dye-sensitized solar cell based on Ni3Se2 array counter electrode shows a high photovoltaic performance with a high photoelectrical conversion efficiency of 4.62%, which is comparable with that of the dye-sensitized solar cell based on platinum counter electrode. To understand the chemical catalysis toward I3- reduction and interfacial charge transfer, the Ni3Se2 array counter electrode has been quantitatively investigated by the electrochemical measurements. The results indicate that the Ni3Se2 array counter electrode exhibits good catalytic activity and direct electron transfer for the reduction of I3-. Our research work will provide insight into the design and fabrication of counter electrode materials with high electrocatalytic performance for dye-sensitized solar cells.