Abstract: Exploiting an alternative of the Pt-based counter electrode (CE) materials for triiodide reduction reaction has become a major interest in the fundamental research of dye-sensitized solar cells (DSCs).Transition-metal selenides (TMSes) was proved a promising non-precious metal electrocatalysts and be used as counter electrode in DSCs.However, the research on TMSes as counter electrode material in DSCs is not enough in-depth and lack systematic research.Two TMSes, Cr5.6Se8 and HfSe3 were prepared by a free-reductant solvothermal method and used them as counter electrodes in high efficiency DSCs.The electrochemical results show that these selenides have excellent catalytic activity for the reduction of triiodine/iodine couple, the conversion efficiencies of corresponding DSCs are 7.27; for Cr5.6Se8 and 7.52; for HfSe3, respectively, comparable to DSCs based on sputtered Pt CE.These results further prove the possibility of selenides as a potential CE materials, and provided a basic research for new selenides.

Key words: Exploiting an alternative of the Pt-based counter electrode (CE) materials for triiodide reduction reaction has become a major interest in the fundamental research of dye-sensitized solar cells (DSCs).Transition-metal selenides (TMSes) was proved a promising non-precious metal electrocatalysts and be used as counter electrode in DSCs.However, the research on TMSes as counter electrode material in DSCs is not enough in-depth and lack systematic research.Two TMSes, Cr5.6Se8 and HfSe3 were prepared by a free-reductant solvothermal method and used them as counter electrodes in high efficiency DSCs.The electrochemical results show that these selenides have excellent catalytic activity for the reduction of triiodine/iodine couple, the conversion efficiencies of corresponding DSCs are 7.27; for Cr5.6Se8 and 7.52; for HfSe3, respectively, comparable to DSCs based on sputtered Pt CE.These results further prove the possibility of selenides as a potential CE materials, and provided a basic research for new selenides.