Auspicious energy conversion performance of dye-sensitized solar cells based on Gd2O3-impregnated SmTiO3 perovskite/TiO2 nanocomposite photoelectrodes

Two series of nanocomposite photoanodes were synthesized for dye-sensitized solar cells (DSSCs) including samarium titanate (x% SmTiO3)/TiO2 nanocomposites (x = 2, 4, 6 and 8%) as well as perovskite oxide Gd2O3- impregnated SmTiO3/TiO2 nanocomposites (TiO2+4%SmTiO3/Gd2O3) with various weight percentages of Gd2O3 (1, 2.5, 5, and 7.5 wt%) nanoparticles. Photovoltaic performances of DSSCs based on (x% SmTiO3)/TiO2 nanocomposites photoelectrodes verified that the champion device in the first series contained TiO2+4%SmTiO3 as it exhibited utmost power conversion efficiency (PCE) of 5.31 +/- 0.03%. Among DSSCs assembled with second series of TiO2+4%SmTiO3/Gd2O3 photoanodes, it was found that impregnation of 5% Gd2O3 afforded the highest PCE of 8.08 +/- 0.06%, fill factor (FF) of 57.53%, open circuit voltage (VOC) of 779 mV and short-circuit current density (JSC) of 18.03 mA cm-2. Such boosted photovoltaic efficiency was associated with significantly improved IPCE great dye loading, lowest charge transfer resistance, highest capacitance, and favorable visible photons absorption by the designed photoelectrode.