Improved photovoltaic performance of dye sensitized solar cell by decorating TiO2 photoanode with Li-doped ZnO nanorods

Abstract Li-doped ZnO nanorods with a diameter of 200 nm and a length of 1 μm were vertically grown on TiO2 photoanodes of dye-sensitized solar cells (DSSCs) via the hydrothermal route at 90 °C. The morphology, crystal structure and photoluminescence of Li-doped ZnO nanorods were examined. It is found that 10 mol% Li doping of the ZnO nanorods can dramatically improve the photovoltaic performance of ZnO nanorods decorated DSSCs. The efficiency of the DSSCs decorated with Li-doped ZnO nanorods reaches 2.50%, which is about fourfold higher than that of DSSCs decorated with undoped ZnO nanorods (0.54%). The improved efficiency of ZnO nanorods decorated DSSCs can be ascribed to the reduced resistivity in ZnO nanorods, which suppresses the electron recombination loss and enhances the open-circuit voltage and short-circuit current density.