Enhanced Performance of Dye-Sensitized Solar Cells with Surface-treated Titanium Dioxides

Abstract

This work reports on the preparation of lithium acetate (LA)-incorporated TiO₂ electrodes by a very simple dip coating process and the effects of the modified electrode on the photovoltaic properties of dye-sensitized solar cells (DSSCs). The DSSC with a LA-modified TiO₂ layer exhibited an increase in both open circuit voltage and fill factor, resulting in a power conversion efficiency of 7.69% compared to that of a reference device with bare TiO₂ (6.82%). By monitoring the changes in electrochemical impedance spectra, dark current-voltage characteristics and incident photon-to-current conversion efficiency, it was revealed that the incorporated LA functioned as a surface dipole on the TiO₂ electrode.