Titanium mesh-supported "TiO2 nanowire arrays/Yb-Er-F tri-doped TiO2 up-conversion nanoparticles" composite structure: Designation for high efficient flexible dye-sensitized solar cells.

Titanium (Ti) mesh-supported "TiO 2 nanowire arrays (TNWAs)/Yb-Er-F tri-doped TiO 2 up-conversion nanoparticles (YEF-TiO 2 -UCNPs)" composite structures were prepared as photoanodes of the flexible dye-sensitized solar cells (DSSCs) by using hydrothermal and spin-coating approaches. The as-synthesized YEF-TiO 2 -UCNPs which could enhance the absorption of N719 dyes by converting the near-infrared light to visible light exhibited better up-conversion luminescence properties than the Yb Er co-doped TiO 2 up-conversion nanoparticles (YE-TiO 2 -UCNPs). Moreover, the appropriate YEF-TiO 2 -UCNPs could enlarge light harvesting range of the formed flexible photoanode and improved the photovoltaic performance of the DSSCs. Under the simulated solar irradiation of 100 mW cm−2 (AM 1.5G), the flexible DSSC with a Ti mesh-supported "TNWAs/YEF-TiO 2 -UCNPs 60% P25 40% " composite structure achieved a short-circuit current density (J sc) of 12.81 mA cm−2 and a power conversion efficiency (PCE) of 5.54%, showing improvements of 45.7% and 37.8% as compared with TNWAs/P25 100% (8.79 mA cm−2, 4.02%), respectively. • Ti mesh-supported "TNWAs/YEF-TiO 2 -UCNPs x P25 1-x " composite was hydrothermally prepared. • The "TNWAs/YEF-TiO 2 -UCNPs x P25 1-x " composites fully flexible DSSCs were constructed. • YEF-TiO 2 -UCNPs expanded the incident light utilization range of the flexible DSSCs. • "TNWAs/YEF-TiO 2 -UCNPs 60% P25 40% " based flexible DSSC exhibited enhanced PCE of 5.54%. [ABSTRACT FROM AUTHOR]