Nano-embossed hollow spherical TiO₂ as bifunctional material for high-efficiency dye-sensitized solar cells

Nano-embossed hollow spherical TiO₂ (NeHS TiO₂) was experimentally investigated for use in high-efficiency dye-sensitized solar cells. This bifunctional material was synthesized in a 0.2 M tetrabutyl ammonium hydroxide (TBAH) environment during a solvothermal reaction without addition of any templates or surfactants. The synthesized NeHS TiO₂ phase exists in the anatase from without any impurities as observed from the X-ray diffraction (XRD) pattern. The reflectance of bare NeHS and CCIC TiO₂ films was found to be much higher than that of the bare nanocrystalline TiO₂ film, which indicated that the particles in the former two films have a higher light scattering ability than those in the nanocrystalline TiO₂ film. Microtome technique confirmed that the walls of the obtained hollow spheres were composed of nanocrystalline anatase TiO₂ particles with mesoporous structure.