Efficient and Stable Z907-Based Dye-Sensitized Solar Cells Enabled by Suppressed Charge Recombination and Photocatalytic Activity

Dye-sensitized solar cells (DSSCs) based on the TiO2 photoanode are promising contenders for photovoltaic technology. However, the TiO2 photoanode shows severe charge recombination and leads to rapid photodegradation of absorbed dyes due to its photocatalytic activity. Herein, we developed a hybrid photoanode by embedding a multifunctional fulleropyrrolidine (PCBO-3) into a TiO2 film. The hybrid film presents higher electron mobility, aligned energy level with dyes, and reduced oxygen vacancy defects, synergistically contributing to suppressed charge recombination and photocatalytic activity. Moreover, the dye molecules can form hydrogen bonds with PCBO-3 molecules, thus enhancing dye loading and photon harvesting. The resulting DSSCs based on hybrid photoanode yield efficiencies of 11.6% under standard one sun illumination and 32.8% under 1500 lx dim light, representing the highest values for Z907-based DSSCs. The encapsulated devices show enhanced long-term operational stability, retaining 76.8% and 89.3% of the initial PCE under standard one sun and dim light for 500 h, respectively. In contrast, only 48.9% and 69.5% of their original efficiency could be maintained for control devices. Our results suggest that hybrid anode is a facile approach to revitalizing DSSCs.