Surface modification and retardation of back reaction by nitrogen ion-beam treatment in dye-sensitized solar cells

The photovoltaic performances and charge recombination of the dye sensitized solar cells (DSSCs) using N-modified TiO2 photoelectrodes were investigated under different ion-beam conditions. N-modified TiO2 films exhibited significantly enhanced BET surface area of 92.19 m2/g with the pore volume of 0.283 cm3/g compared to the surface area of 56.65 m2/g with a pore volume of 0.141 cm3/g of pristine TiO2 film. The interstitial and substitutional affixations of nitrogen atom inside the TiO2 lattice were confirmed by XPS and Raman spectroscopy. A 26% improvement in conversion efficiency was achieved by using N+ ion-beam treated TiO2 photoelectrode.