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

Abstract

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).