Indexed on: 25 Jan '17Published on: 25 Jan '17Published in: ACS Applied Materials & Interfaces
TiO2 nanocrystals with different reactive facets have been attracted extensive interest since their syntheses. The anatase TiO2 nanocrystals with (001) or (100) dominated facets were considered to be excellent electrode materials to enhance the cell performance of dye sensitized solar cells. However, which reactive facet presents the best surface for benefiting photovoltaic effect is still unknown. We report a systematic study of various anatase TiO2 surfaces interacting with N719 dye by means of DFT calculations in combination with microscopic techniques. (001) surface interacting with N719 would have the lowest work function, leading to the best photovoltaic performances. To further increase the efficiency, Nb dopant was incorporated into the anatase TiO2 nanocrystals. Based on the theoretical prediction, we proposed and demonstrated a novel Nb-doped (001) dominated anatase TiO2 nanosheets as photoelectrode in a dye-sensitized solar cell to further enhance the open-circuit voltage. And a power conversion efficiency of 10% was achieved, which was 22% higher than that of the undoped device (P25 as an electrode).