Titania Aerogels as a Superior Mesoporous Structure for Photoanodes of Dye-Sensitized Solar Cells

Titania aerogels, because of their structural advantages of high porosities, high specific surface areas and three-dimensionally well-connected through pore structure, are demonstrated an excellent mesoporous structure for photoanodes of dye-sensitized solar cells. A power conversion efficiency improvement of 16% (7.22 vs. 8.36%) is achieved as compared with a P25 TiO2 based cell. The structural advantages of titania aerogels in serving the functionalities of the photoanode are manifested with a smaller effective back electron transfer rate constant, 9.6 vs. 13.1 s-1, a higher steady-state conduction band electron density, 32% more, and a longer electron life time, 398 vs. 199 ms, of the photoanode as compared with that of the P25 TiO2 based one.