Photovoltaic Performance of Dye-Sensitized Solar Cells Under Low Illumination by Modification of a Photoanode With ZnFe2O4/TiO2 Nanofibers

In this study, the content of ZnFe2O4/TiO2 nanofibers were synthesized by electrospinning technology with various ratios of 1%, 3% and 5%. Then ZnFe2O4/TiO2 nanofibers were applied to modify photoanodes of dye-sensitized solar cells (DSSCs). This study demonstrates that the conversion efficiency under different light intensities of the DSSC modified by 3% ZnFe2O4/TiO2 nanofibers is superior to that of the other DSSCs. At a light intensity of 100 mW/cm(2), the efficiency is 5.78%, which is 69.5% improvement over the pure TiO2-based DSSC (3.41%). The conversion efficiency of the DSSC modified by 3% ZnFe2O4/TiO2 nanofibers is the highest about 7.92% at a light intensity of 30% mW/cm(2). The critical role of ZnFe2O4 in promoting photovoltaic performance is demonstrated by use of incident photocurrent conversion efficiency (IPCE) and electrochemical impedance spectroscopy (EIS). EIS analysis confirms that the DSSC modified by 3% ZnFe2O4/TiO2 nanofibers possesses superior photoelectrochemical performance with a maximum IPCE value of 49% at a wavelength of 530 nm. The DSSC modified by 3% ZnFe2O4/TiO2 nanofibers does not only have high efficiency, but also improve the dye adsorption performance.