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

Modifications of the working electrode with TiO₂ blocking or coating layers are carried by electrodeposition in TiCl₃ precursor solution. The results suggest that the electrodeposited TiO₂ blocking layer provides excellent agglutination between the FTO substrate and the active TiO₂ layer. In addition, the electrodeposited TiO₂ coating layer enhances the interconnections between the TiO₂ nanoparticles and the FTO substrate, and therefore it increases the electron transport efficiency. The morphology and crystalline structure of the electrodeposited TiO₂ 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 TiO₂ film. The photoelectron conversion efficiency of DSSC is increased from 3. 47% to 5. 38% by employing the TiO₂ electrodeposited working electrode.