Enhancing photoelectrical performance of dye–sensitized solar cell by doping SrTiO3:Sm3+@SiO2 core–shell nanoparticles in the photoanode.

SrTiO 3 :Sm 3+ @SiO 2 (STS@SiO 2 ) core–shell nanoparticles were fabricated by Stöber method after a simple hydrothermal process and then being introduced into the TiO 2 photoanode to assemble dye–sensitized solar cells (DSSCs). X–ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and transmission electron microscope (TEM) analysis confirmed the formation of core–shell nanoparticles with cubic structured SrTiO 3 :Sm 3+ (STS) as core, SiO 2 as shell. The photo–fluorescence (PL) and ultraviolet–visible (UV–Vis) absorption spectra of photoanodes with different STS@SiO 2 content indicate a down–conversion from ultraviolet light to visible light which matched the strong absorbing region of the N719 dye. Compared with the pure TiO 2 and STS doped TiO 2 photoanode, STS@SiO 2 doped TiO 2 photoanode showed a greater photovoltaic efficiency. The photoelectric conversion efficiency ( η ) of 5.07% for 10 wt% STS@SiO 2 doped TiO 2 –based DSSC was higher than that of 3.72% for pure TiO 2 –based DSSC and 4.29% for 10 wt% STS doped TiO 2 –based DSSC. This phenomenon could be explained by STS@SiO 2 core–shell nanoparticles’ triple ability to extend spectral response range to the ultraviolet region, suppress the recombination of electron–electrolyte and lengthen the light traveling distance in the photoanode by the scattering. [ABSTRACT FROM AUTHOR]