ZnO-nanowire-covered TiO2 Thin-film Electrodes for Improving the Photovoltaic Properties of Dye-sensitized Solar Cells

초록

We report on ZnO nanowires (ZnO NWs), which were grown on the surface of a TiO2 thin-film electrode with zinc dihydrate acetate seeds by using thermal chemical vapor deposition. Detailed morphological properties revealed that the grown ZnO NWs fully covered the surface of the TiO2 thin-film electrode. The grown ZnO-NW-covered TiO2 thin films (ZnO NW/TiO2 thin-film) were used as working electrodes in dye-sensitized solar cells (DSSCs). We observed that a covering of ZnO NWs on the TiO2 thin-film electrodes improved the open-circuit voltage V-OC and the fill factor FF while significantly decreasing the short-circuit current density J(SC) the and photovoltaic performance of the ZnO NW/TiO2 thin-film DSSCs compared to there for bare TiO2 thin-film DSSCs. The V-OC and the FF of the ZnO NW/TiO2 thin-film based DSSCs were enhanced by about 10 - 15% compared to the values for bare TiO2 thin-film DSSCs. One can attribute the enhanced V-OC and FF to the larger size of upstanding ZnO NWs on the TiO2 thin-film substrate, which slow surface recombination between the anode electrode and the electrolyte.

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