Enhancing photovoltaic performance of dye-sensitized solar cells by rare-earth doped oxide of SrAl2O4:Eu3+

SrAl2O4:Eu3+ down-conversion (DC) nanocrystals were synthesized by a sol-gel method and then doped in TiO2 as a photoanode in dye-sensitized solar cells (DSSCs). Differential thermal analysis, fourier transform infrared spectroscopy, X-ray diffraction and Brunauer-Emmet-Teller analysis confirmed the formation of SrAl2O4:Eu3+ nanocrystals with diameters of similar to 47 nm, pore size of similar to 25 nm, sintering temperature of 1300 degrees C. The photoluminescence and UV-vis absorption spectra of the SrAl2O4:Eu3+ revealed a DC from ultraviolet light to visible light which matched the strong absorbing region of the N719 dye. The photoelectric conversion efficiency of the DSSCs with a TiO2 photoanode doped with 3 wt% SrAl2O4:Eu3+ was 20% higher than that with a pure TiO2 photoanode. This phenomenon could be mainly explained by SrAl2O4:Eu3+ nanocrystals' ability of DC and increased the short-circuit current density. It could be minorly due to the p-type doping effect and slightly improved the open-circuit voltage. (C) 2016 Elsevier Ltd. All rights reserved.