Efficiency enhanced dye-sensitized Zn2SnO4 solar cells using a facile chemical-bath deposition method

The surface treatment of zinc stannate (Zn2SnO4) film for use in dye-sensitized solar cells has been carried out with zinc tin oxide precursor solutions through chemical-bath deposition (CBD). Mott Schottky measurements demonstrate that the flat band of Zn2SnO4 has a moderate positive shift owing to the surface treatment, which leads to a slightly decreased V-oc. Although UV-vis spectroscopy reveals that the adsorption amounts of N719 and D131 dyes are decreased, EIS results and OCVD data suggest that the decreased charge recombination rate and prolonged electron lifetime give rise to an apparently improved efficiency of cells. Consequently, an enhancement of 13.5% is obtained after CBD surface treatment under the illumination of one sun (AM 1.5, 100 mW cm(-2)).