Efficient Light Harvesting and Charge Collection of Dye-Sensitized Solar Cells with (001) Faceted Single Crystalline Anatase Nanoparticles

With a comparable specific surface area, 17% enhanced dye-loading capacity was observed for the first time in the (001) faceted TiO2 single crystals compared to that of benchmark P25 nanoparticles, thus generating a significant enrichment in both short-circuit photocurrent density and power conversion efficiency of dye-sensitized solar cells (DSCs). Such a remarkably increased dye-loading capacity was primarily ascribed to the higher density of 5-fold-coordinnated Ti atoms on the (001) surfaces. Furthermore, kinetic studies revealed that such single crystals confer a higher electron lifetime and charge collection efficiency compared with conventional P25 electrode, which might originate from the specific surface configuration in these high energetic facet dominant single crystals. Our study provides straightforward evidence for the superior reactivity of (001) facets and implies that such single TiO2 crystals with high-energetic facets would be a promising electrode material for DSCs.