Pt/Y₂O₃: Eu³⁺ composite nanotubes: Enhanced photoluminescence and application in dye-sensitized solar cells

Y(OH)₃: Eu³⁺ nanotubes were synthesized using a facile hydrothermal method, and then, Pt particles were grown on the surface of the nanotubes using a combination of vacuum extraction and annealing. The resulting Pt/Y₂O₃: Eu³⁺ composite nanotubes not only exhibited enhanced red luminescence under 255- or 468-nm excitation but could also be used to improve the efficiency of dye-sensitized solar cells, resulting in an efficiency of 8.33%, which represents a significant enhancement of 11.96% compared with a solar cell without the composite nanotubes. Electrochemical impedance spectroscopy results indicated that the interfacial resistance of the TiO₂-dye|I₃^-/I^- electrolyte interface of the TiO₂-Pt/Y₂O₃: Eu³⁺ composite cell was much smaller than that of a pure TiO₂ cell. In addition, the TiO₂-Pt/Y₂O₃: Eu³⁺ composite cell exhibited a shorter electron transport time and longer electron recombination time than the pure TiO₂ cell.