A way to achieve a high-efficiency dye-sensitized solar cell is to combine an n-type TiO2-based photoanode with a p-type photocathode in a tandem configuration. The development of an efficient photocathode is, at present, the key target. We have optimized the NiO, I-3(-)/I- p-DSSC system to obtain record photocurrent, giving 64% incident photon-to-current conversion efficiency (IPCE) and 5.48 mAcm(-2) J(SC).