Somekawa, S.; Kusumoto, Y.; Yang, H.; Abdulla-Al-Mamun, M.; Ahmmad, B. Fabrication, N-Doping Mechanism and Evaluation of N-Doped TiO<sub>2</Sub> Thin Films Based on Laser Ablation Method. J. Sci. Res. 2009, 2, 17-23.