Dual functions of YF(3):Eu(3+) for improving photovoltaic performance of dye-sensitized solar cells

In order to enhance the photovoltaic performance of dye-sensitized solar cell (DSSC), a novel design is demonstrated by introducing rare-earth compound europium ion doped yttrium fluoride (YF(3):Eu(3+)) in TiO(2) film in the DSSC. As a conversion luminescence medium, YF(3):Eu(3+) transfers ultraviolet light to visible light via down-conversion, and increases incident harvest and photocurrent of DSSC. As a p-type dopant, Eu(3+) elevates the Fermi level of TiO(2) film and thus heightens photovoltage of the DSSC. The conversion luminescence and p-type doping effect are demonstrated by photoluminescence spectra and Mott-Schottky plots. When the ratio of YF(3):Eu(3+)/TiO(2) in the doping layer is optimized as 5 wt.%, the light-to-electric energy conversion efficiency of the DSSC reaches 7.74%, which is increased by 32% compared to that of the DSSC without YF(3):Eu(3+) doping. Double functions of doped rare-earth compound provide a new route for enhancing the photovoltaic performance of solar cells.