Hierarchical TiO2 Submicrorods Improve the Photovoltaic Performance of Dye-Sensitized Solar Cells

Hierarchical TiO2 submicrorods (HTRs) assembled from tiny nanoparticles and nanorods were synthesized through a facile hydrothermal method using titanate glycolate rods as a self-template. The as-prepared hierarchical TiO2 submicrorods possessed a higher surface area (103 m(2) g(-1)) than P25 nanoparticles (NPs) (55 m(2) g(-1)). Composite photoanodes in dye-sensitized solar cells (DSSCs) were prepared by integrating the prepared HTRs and P2S NPs, and a photovoltaic conversion efficiency of 8.09% was obtained, which was obviously higher than that of the pristine P25 NPs-based photoanode (5.37%). The incorporated hierarchical TiO2 submicrorods in the hybrid photoanode film showed three functions in the enhancing photovoltaic performance of DSSCs: (i) increasing the specific surface area for effective adsorption of dye molecules, (ii) enhancing the light harvesting efficiency, and (iii) accelerating the electron transport by the films. This work highlights the importance of tuning the structure of the photoanode and exhibits an efficient strategy for enhanced energy conversion of DSSCs.