Mo phosphide (MoP), Ni phosphide (Ni5P4), and C-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 org. 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%).