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

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 (eta) of 7.34%, indicating a 57% and 30% increase in J(sc) and eta 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 eta of 5.64%.