Effects of Ag-ion implantation on the performance of DSSCs with a tri-layer TiO2 film

Tri-layer titania films were doped with Ag ions using MEVVA ( metal vapor vacuum arc) ion-implantation, and characterized for photovoltaic performance in dye-sensitized solar cells ( DSSCs). The current density was significantly improved with the increasing numbers of implanted Ag-ions. The highest energy-efficiency of 5.85% was achieved for the modified DSSCs by Ag-ion implantation with 1 x 10(16) atom per cm(-2). The enhancement effect of Ag-ion implantation on photoelectric performance of the DSSCs contributed toward the decrease in charge-transfer resistance and enhancement of dye adsorption. In addition, the Ag-doping induced an impurity level, which reduces the recombination rate of electrons and positively shifts the conduction band edge of titania to match the LUMO level of the dye.