Effect of hybrid nanocrystalline TiO2/Au film on the photoelectrode of dye-sensitized solar cell

In this study, we used a citrate reduction method and electrophoretic deposition (EPD) to prepare hybrid nanocrystalline TiO2/Au films and applied on the photoelectrode of dye-sensitized solar cell. The films and solar cells were investigated by field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis (EDX), I-V characteristics, and electrochemical impedance spectroscopy (EIS) analyses. In the FE-SEM analysis, TiO2/Au hybrid layers have the porous structure that is advantageous in the dye-loading capacity. The results of EDX reveal that the TiO2/Au hybrid layer containing 0.28 wt% gold nanoparticles. Under sunlight simulator (AM 1.5 100 mW/cm2) illumination, the conversion efficiency of dye-sensitized solar cell with TiO2/Au hybrid layer is obviously higher than TiO2 film. In the analysis of electrochemical impedance spectroscopy (EIS), the total impedance of hybrid TiO2/Au photoelectrode is 98.9 W, which is lower than that of TiO2 film photoelectrode. These results indicate that TiO2/Au hybrid layer can increase the conductivity and reduce the recombination of charges in the photoelectrode, resulting in the increase of conversion efficiency for DSSCs.