Mesoporous TiO2 nanowires as bi-functional materials for dye-sensitized solar cells

A bimodal structured TiO2 nanowire (NW) was synthesized via metal glycolate-mediated method. Each large NW was comprised of a few nanometers-sized anatase particles, which led to a high specific surface area, 50.4 m2 g−1. When the bimodal TiO2 NWs were coated onto a spherical nanoparticle-based active layer of the photoelectrode for a dye-sensitized solar cell, the reflectance of the photoelectrode increased by 4-times, compared to a bare active layer. The TiO2 NWs increased quantum efficiency of the dye-sensitized solar cell, from 400 to 800 nm wavelengths, which was attributed to both the light-scattering and charge generating effects due to the capability of reflecting incident light and adsorbing large amount of dye molecules.

► Micrometer-sized TiO2 wires comprised of very tiny nanoparticles were synthesized. ► The nanowire has a high specific surface area. ► The nanowire exhibits efficient light-scattering property. ► The nanowire improved light-harvesting property of dye-sensitized solar cells.