Variable temperature spectroelectrochemistry study of silver-doped TiO2 and its influence on the performance of dye sensitized solar cells

Abstract

Ag-doped TiO₂ nanoparticles are prepared and used as semiconductor materials of photoanodes to improve the performance of dye sensitized solar cells (DSSCs). The results of variable temperature spectroelectrochemistry study show that the conduction band edge of Ag-doped TiO₂ shifts positively, which enhances the driving force of electrons and improves the electron injection efficiency from the LUMO of the dye to the conduction band of TiO₂. The deposition of Ag not only benefits efficient charge transfer but also could minimize the charge recombination process, resulting in a significant photocurrent enhancement. At the optimum Ag concentration of 1.2 at%, the DSSC exhibited a J_sc of 19.75 mA cm⁻², a V_oc of 0.73 V, and a FF of 0.57 with an energy conversion efficiency (η) of 7.34%, indicating a 57% and 30% increase in J_sc and η respectively than that of DSSC based on an undoped TiO₂ photoanode, which gives a J_sc of 12.61 mA cm⁻², a V_oc of 0.75 V, and a FF of 0.59 with a η of 5.64%.