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.