Synthesis of Nanocrystalline N-Doped TiO2 and Its Application on High Efficiency of Dye-Sensitized Solar Cells

Nanocrystalline of Nitrogen-doped TiO2 (N-doped TiO2) has been synthesized through the hydrolysisof N-substituted titanium isopropoxide precursors. The XRD result showed that the structure ofannealed N-doped TiO2 was anatase. The pore properties were investigated from nitrogen gas sorptionanalyzer, showing mesoporous structure of its N-doped TiO2 with a high specific surface area (167m2/g) and a sharp pore radius distribution. The substitution of oxygen sites with nitrogen atoms in thetitania structure was confirmed by X-ray photoemission spectroscopy (XPS) with 3.6% nitrogencontain. A clear decrease in the band gap on N-doped TiO2 (compared to Degussa P25) is deducedfrom the optical absorption spectroscopy results. Application of synthesized nanocrystalline N-dopedTiO2 on dye-sensitized solar cells resulted 4.8% overall conversion efficiency, which was higher thanthe Degussa P25.