Vanadium Doped CoP on a Carbon Paper Composite as a Counter Electrode for Dye-Sensitized Solar Cells

We present facile two-step hydrothermal and chemical vapor deposition approaches for in situ growth of cobalt phosphide and vanadium phosphide (CoP/V2P) on carbon paper (CP). The as-prepared CoP/V2P/CP composite can be used as counter electrodes (CEs) for dye-sensitized solar cells (DSSCs) without any post-treatment. It is found that the CoP/V2P/CP CE exhibits higher electrocatalytic activity than that of the Pt CE and the comforting charge-transfer resistance of 9.53 Ω·cm2 for the reduction of the triiodide electrolyte. Therefore, the DSSC with the CoP/V2P/CP CE generates a higher power conversion efficiency (9.47%) than that of the Pt CE (7.43%) under optimized conditions.