Dye-sensitized solar cells with anatase TiO₂ nanorods prepared by hydrothermal method

The hydrothermal method provides an effective reaction environment for the synthesis of nanocrystalline materials with high purity and well-controlled crystallinity. In this work, we started with various sizes of commercial TiO₂ powders and used the hydrothermal method to prepare TiO ₂ thin films. We found that the synthesized TiO₂ nanorods were thin and long when smaller TiO₂ particles were used, while larger TiO₂ particles produced thicker and shorter nanorods. We also found that TiO₂ films prepared by TiO₂ nanorods exhibited larger surface roughness than those prepared by the commercial TiO₂ particles. It was found that a pure anatase phase of TiO₂ nanorods can be obtained from the hydrothermal method. The dye-sensitized solar cells fabricated with TiO₂ nanorods exhibited a higher solar efficiency than those fabricated with commercial TiO₂ nanoparticles directly. Further, triple-layer structures of TiO₂ thin films with different particle sizes were investigated to improve the solar efficiency.