Effect of ZnO /TiO_2 core-sheath thickness ratios on performance of dye sensitized solar cells

To explore the effect of different core-sheath thickness ratios on the photoelectric performance of a dye sensitized solar cell( DSSC),the coaxial electrospinning was used to control different spinning core-sheath solution flow rate ratios for different thickness ratios of core-sheath ZnO /TiO2 nanofibers.Field emission scanning electron microscopy( FE-SEM),transmission electron microscopy( TEM),Fourier infrared spectroscopy( FT-IR) and X-ray diffraction( XRD) were used to characterize the coresheath nanofibers. The results revealed that the nanofiber is composed of wurtzite ZnO as the sheath and anatase TiO2 as the core. Then,the ZnO /TiO2core-sheath nanofibrous membranes were utilized as photoanode material to assemble the dye sensitized solar cell. At last,it was found that when the core-sheath spinning flow rate ratio is 1∶ 1,the diameter of core-sheath nanofibers is about 154 nm and the core layer is about 90 nm in diameter,and the dye adsorption amount is the largest and the DSSC based on the coresheath nanofibers has the highest efficiency up to 5. 47%,which is 22% higher than DSSC assembled from the TiO2 nanofibers.