Ag nanoparticle-modified double-layer composite film based on P25/NaLuF4:Yb3+/Er3+ and flower TiO2 for highly efficient dye-sensitized solar cells

Abstract A composite film was prepared by mixing NaLuF 4 :Yb 3+ /Er 3+ up-conversion luminescent material with commercial P25, and a scattering layer composed of flower-like TiO 2 was added on to the composite film (UC/P25) to form a double-layer composite film (UC/P25 + FT). An AgNO 3 solution was irradiated by ultraviolet light to deposit nano-Ag particles on the prepared double-layer film, and a nano-Ag modified double-layer film (UC/P25 + FT + Ag) was finally obtained. The synergistic effect of the three improved methods conferred the UC/P25 + FT + Ag film with a wide spectral absorption range, strong light-scattering ability, and strong light absorption capability, which greatly improved the photoelectric performance of the film. The maximum photoelectron conversion efficiency of dye-sensitized solar cells with the UC/P25 + FT + Ag photoanode reached up to 8.14%, which increased by 32.36% compared with that of the pure P25 film photoelectrode.