Dye-sensitized solar cells based on indium-tin oxide nanowires coated with titania layers

The concept of growing ITO (Indium-Tin-oxide) or ITO/TiO₂ core-shell nanowire arrays for the use of 3D electrodes in dye-sensitized solar cells (DSSCs) has been tested in the present study. By employing the template electrophoretic deposition (EPD) method, ITO and ITO/TiO₂ nanowire arrays were synthesized. A 3D electrode for DSSCs was constructed using a doctor blade to coat TiO₂ layers covering the ITO or ITO/TiO₂ nanowire arrays. The separation of charge generation, charge transport functions, enlarged interface area were thought to be the major advantages of 3D nanowire electrodes for the optimization of DSSCs. Photoelectric conversion efficiency at 3.99% of the DSSCs made from ITO nanowires was obtained, which was much higher than those of ITO/TiO₂ core- shell nanowire arrays or pristine TiO₂ films. The morphology of ITO/TiO₂ core-shell nanowire arrays is sensitive to fabrication process and significantly affects the final performance. Cyclic voltammetry confirmed that the reaction current was significantly enhanced when a 3D ITO nanowire electrode was used.