Effect of Surface Modification to Photoanodes in Alkoxysilyl Dye-Sensitized Solar Cells on the Photovoltaic Performance

摘要

The effect of surface modification to dye-adsorbed TiO_2 electrodes in alkoxysilyl dye-sensitized solar cells on the photovoltaic performance was investigated with using alkylcarboxylic acids with different alkyl-chain lengths as surface modifiers. More effective suppression of a back-electron-transfer reaction was observed with the increment of the amount of the adsorbed modifier on the dye-adsorbed TiO_2 electrode and with lengthening the alkyl chain of the alkylcarboxylic acid. The photovoltaic performance of the cells was confirmed to be improved by the surface modifications of the dye-adsorbed TiO_2 electrodes using alkylcarboxylic acids, and the necessities of tuning the surface-modification degree and the selection of the alkyl-chain length with regarding the molecular size of the sensitizing dye were exhibited for the efficient improvement of the photovoltaic performance of the cell.