Improving photovoltaic performance of dye-sensitized solar cell by downshift luminescence and p-doping effect of Gd2O3:Sm3+

► Doped RE oxide Gd2O3:Sm3+ is introduced into TiO2 film in dye-sensitized solar cell. ► RE ions increase light harvest via downshift luminescence and thus photocurrent. ► RE ions enhance the energy level of TiO2 film and thus photovoltage. ► Solar cell doped Gd2O3:Sm3+ achieves conversion efficiency of 6.72%, which is increased by 12.6% compared with a solar cell lacking of Gd2O3:Sm3+.