Enhanced photoelectric conversion efficiency of dye-sensitized solar cells by the synergetic effect of NaYF4:Er3+/Yb3+ and g-C3N4

Abstract

TiO2-NaYF4:Er3+/Yb3+-C3N4 composite photoanodes were successfully designed for the first time. The photoelectric conversion efficiency of TiO2-NaYF4:Er3+/Yb3+-C3N4 composite cell can result an efficiency of 7.37%, which is higher than those of pure TiO2 cell and TiO2-C3N4 composite cell. The enhancement of the efficiency can be attributed to the synergetic effect of NaYF4:Er3+/Yb3+ and C3N4. Electrochemical impedance spectroscopy analysis revealed that the interfacial resistance of the TiO2-dye I3-/I− electrolyte interface of TiO2-NaYF4:Er3+/Yb3+-C3N4 composites cell was much smaller than that of pure TiO2 cell. In addition, the TiO2-NaYF4:Er3+/Yb3+-C3N4 composite cell had longer electron recombination time and shorter electron transport time than that of pure TiO2 cell.