Improved electrochemical performance of dye-sensitized solar cell via surface modifications of the working electrode by electrodeposition

Modifications of the working electrode with TiO 2 blocking or coating layers are carried by electrodeposition in TiCl 3 precursor solution. The results suggest that the electrodeposited TiO 2 blocking layer provides excellent agglutination between the FTO substrate and the active TiO 2 layer. In addition, the electrodeposited TiO 2 coating layer enhances the interconnections between the TiO 2 nanoparticles and the FTO substrate, and therefore it increases the electron transport efficiency. The morphology and crystalline structure of the electrodeposited TiO 2 layers are characterized by SEM, TEM, and XRD. The electrochemical impedance spectroscopy measurements show that the improved DSSC performance with the electrodeposited coating layer is mainly due to the increase in the lifetime of the conduction band electron in the TiO 2 film. The photoelectron conversion efficiency of DSSC is increased from 3.47% to 5.38% by employing the TiO 2 electrodeposited working electrode.