High-performance phosphide/carbon counter electrode for both iodide and organic redox couples in dye-sensitized solar cells

In the present study, molybdenum phosphide (MoP), nickel phosphide (Ni5P4), and carbon-supported Ni5P4 (Ni5P4/C) were proposed for use as counter electrode (CE) catalysts in dye-sensitized solar cells (DSCs) for the regeneration of both the conventional I3−/I− redox couple and a new organic T2/T− redox couple. For the I3−/I− redox couple, the DSCs using MoP and Ni5P4 CE yielded a power conversion efficiency (PCE) of 4.92 and 5.71%, and the DSC using Ni5P4/C showed a high PCE of 7.54%, which was close to that of the DSC using Pt CE (7.76%). For the T2/T− redox couple, Ni5P4/C performed much better than Pt and the DSC using Ni5P4/C CE showed a PCE of 4.75%, much higher than the photovoltaic performance of the DSC using Pt CE (3.38%).