Triplex-functional corolla-like TiO2 nanorod aggregates as light-scattering layer for dye-sensitized solar cells

A bilayer-structural TiO2 photoelectrode was constructed by fabricating corolla-like TiO2 nanorod-aggregate light-scattering overlayer directly on the tips of TiO2 nanocrystallite underlayer through a facile hydrothermal method and studied for improved energy conversion efficiency in dye-sensitized solar cells (DSSCs). The corolla-like TiO2 nanorod-aggregate overlayer can provide efficient light scattering without sacrificing the accessible surface area for sufficient dye adsorption together with a direct path for fast electron transport, resulting in a high short photocurrent density of 18.34 mA cm–2 and an energy conversion efficiency of 6.07%, which are 44.6% and 42.5% higher than those of the DSSC based on pure TiO2 nanocrystallites respectively.

► Corolla-like TiO2 nanorod-aggregate light-scattering layer was fabricated directly on the tips of nanocrystallites. ► It can generate efficient light scattering without sacrificing accessible surface area for dye loading. ► It provides direct path for electron transport. ► It exhibits improved performance for dye-sensitized solar cells.