Cost-effective dye-sensitized solar cells based on rutile-phase three-dimensional TiO₂ hierarchical nanostructures

Specifically engineered three-dimensional (3D) and 1D morphologies are expected to play significant roles in the development of next-generation dye-sensitized solar cells. In this study, using a hydrothermal approach without a surfactant or template, we attempted to synthesize a 3D hierarchical rutile titanium dioxide (TiO₂ ) architecture by varying the growth temperature and time. X-ray diffraction patterns of the synthesized TiO₂ correlated well with rutile TiO₂ . Scanning electron microscopy images exhibited different nanostructures, such as nanorods, aggregated nanorods, and 3D TiO₂ microflowers comprised of nanorods at 100°C, 130°C, and 160°C, respectively, after growth for 6 h. A significantly improved efficiency was observed for the TiO₂ microflowers. The TiO₂ microflowers exhibited an efficiency of 1.16%, short-circuit current density of 12.8 mA cm^-2 , open-circuit voltage of 0.692 V, and fill factor of 0.67.