Nb and F co-doped anatase TiO 2 layers were deposited by low pressure chemical vapor deposition (LPCVD) at pressure of 3 mtorr using titanium-tetra-iso-propoxide (TTIP), O 2 and NbF 5 as precursor, oxidant and dopant respectively. Resistivity beyond 100 Ω cm for undoped layer was decreased with increasing supply of the dopant and dependent on the supply ratio of O 2 to TTIP and decreased to 0.2 Ω cm by the optimization. X-ray fluorescent spectroscopy showed Nb-content in the layer was decreased with the O 2 -supply ratio. X-ray photo-spectroscopy indicated that F substituted O-site in TiO 2 by O 2 -supply but carbon-contamination and F missing substitution in the O-site were significantly increased by excess O 2 -supply. Further, it was suggested that the substituted F played an important role to reduce resistivity without significant contribution of O-vacancies. XRD spectra showed F missing substitution in the O-site degraded the crystallinity.
KeywordsLPCVDAnatase-TiO<sub>2</sub>Nb and F Co-DopingLow-Resistive TiO<sub>2</sub>
Assuncao, V., Fortunato, E., Marques, A., águas, H., Ferreira, I., Costa, M.E.V. and Martins, R. (2003) Influence of the Deposition Pressure on the Properties of Transparent and Conductive ZnO:Ga Thin-Film Produced by r.f. Sputtering at Room Temperature. Thin Solid Films, 427, 401-405. http://dx.doi.org/10.1016/S0040-6090(02)01184-7
Lewis, B.G. and Paine, D.C. (2000) Applications and Processing of Transparent Conducting Oxides. MRS Bulletin, 25, 22-27. http://dx.doi.org/10.1557/mrs2000.147
Wang, R., Hashimoto, K. and Fujishima, A. (1997) Light-Induced Amphiphilic Surfaces. Nature, 388, 431-432. http://dx.doi.org/10.1038/41233
Mills, A., Lepre, A., Elliott, N., Bhopal, A., Parkin, I.P. and Neill, S.A. (2003) Characterisation of the Photocatalyst Pilkington ActivTM: A Reference Film Photocatalyst? Journal of Photochemistry and Photobiology A: Chemistry, 160, 213-224. http://dx.doi.org/10.1016/S1010-6030(03)00205-3
Campbell, S.A., Kim, H.S., Gilmer, D.C., He, B., Ma, T. and Gladfelter, W.L. (1999) Titanium Dioxide (TiO2)-Based Gate Insulators. IBM Journal of Research and Development, 43, 383-392. http://dx.doi.org/10.1147/rd.433.0383
Martinet, C., Paillard, V., Gagnaire, A. and Joseph, J. (1997) Deposition of SiO2 and TiO2 Thin Films by Plasma Enhanced Chemical Vapor Deposition for Antireflection Coating. Journal of Non-Crystalline Solids, 216, 77-82. http://dx.doi.org/10.1016/S0022-3093(97)00175-0
Hitosugi, T., Ueda, A., Furubayashi, Y., Hirose, Y., Konuma, S., Shimada, T. and Hasegawa, T. (2006) Fabrication of TiO2-Based Transparent Conducting Oxide Films on Glass by Pulsed Laser Deposition. Japanese Journal of Applied Physics, 46, L86-L88. http://dx.doi.org/10.1143/JJAP.46.L86
Gillispie, M.A., van Hest, M.F.A.M., Dabney, M.S., Perkins, J.D. and Ginley, D.S. (2007) rf Magnetron Sputter Deposition of Transparent Conducting Nb-doped TiO2 Films on SrTiO3. Journal of Applied Physics, 101, 033125-1-4. http://dx.doi.org/10.1063/1.2434005
Hoang, N.L., Yamada, N., Hitosugi, T., Kasai, J., Nakao, S., Shimada, T. and Hasegawa, T. (2008) Low-temperature Fabrication of Transparent Conducting Anatase Nb-doped TiO2 Films by Sputtering. Applied Physics Express, 1, 115001-115003. http://dx.doi.org/143/APEX.1.115001
Di Valentin, C., Pacchioni, G. and Selloni, A. (2009) Reduced and n-Type Doped TiO2: Nature of Ti3+ Species. Journal of Physical Chemistry C, 113, 20543–20552. http://dx.doi.org/10.1021/jp9061797
Li, D., Haneda, H., Hishita, S., Ohashia, N. and Labhsetwar, N.K. (2005) Fluorine-doped TiO2 Powders Prepared by Spray Pyrolysis and Their Improved Photocatalytic Activity for Decomposition of Gas-phase Acetaldehyde. Journal of Fluorine Chemistry, 126, 69-77. http://dx.doi.org/10.1016/j.jfluchem.2004.10.044
Di Valentin, C., Finazzi, E., Pacchioni, G., Selloni, A., Livraghi, S., Czoska, A.M., Paganini, M.C. and Giamello, E. (2008) Density Functional Theory and Electron Paramagnetic Resonance Study on the Effect of N-F Codoping of TiO2. Chemistry of Materials, 20, 3706-3714. http://dx.doi.org/10.1021/cm703636s
Yang, W. and Wolden, C.A. (2006) Plasma-Enhanced Chemical Vapor Deposition of TiO2 Thin Films for Dielectric Applications. Thin Solid Films, 515, 1708-1713. http://dx.doi.org/10.1016/j.tsf.2006.06.010
Ahn, K.H., Park, Y.B. and Park, D.W. (2003) Kinetic and Mechanistic Study on the Chemical Vapor Deposition of Titanium Dioxide Thin Films by In Situ FT-IR using TTIP. Surface Coating and Technology, 171, 198-204. http://dx.doi.org/10.1016/S0257-8972(03)00271-8
Yokozawa, M., Iwasa, H. and Teramoto, I. (1968) Vapor Deposition of TiO2. Japanese Journal of Applied Physics, 7, 96-97. http://dx.doi.org/10.1143/JJAP.7.96
Fictorie, C.P., Evans, J.F. and Gladfelter, W.L. (1994) Kinetic and Mechanistic Study of the Chemical Vapor Deposition of Titanium Dioxide Thin Films using Tetrakis-(Isopropoxo)-Titanium (IV). Journal of Vacuum Science & Technology A, 12, 1108-1113. http://dx.doi.org/10.1116/1.579173
Chen, S., Mason, M.G., Gysling, H.J., Paz-Pujalt, G.R., Blanton, T.N., Castro, T., Chen, K.M., Fictorie, C.P., Gladfelter, W.L., Franciosi, A., Cohen, P.I. and Evans, J.F. (1993) Ultrahigh Vacuum Metalorganic Chemical Vapor Deposition Growth and In Situ Characterization of Epitaxial TiO2 Films. Journal of Vacuum Science & Technology A, 11, 2419-2429. http://dx.doi.org/10.1116/1.578587
Karlsson, P.G., Richter, J.H., Andersson, M.P., Johansson, M.K.-J., Blomquist, J., Uvdal, P. and Sandell, A. (2011) TiO2 Chemical Vapor Deposition on Si(111) in Ultrahigh Vacuum: Transition from Interfacial Phase to Crystalline Phase in the Reaction Limited Regime. Surface Science, 605, 1147-1156. http://dx.doi.org/10.1016/j.susc.2011.03.001
Schmidt, S., Goyenola, C., Gueorguiev, G.K., Jensen, J., Greczynski, G., Ivanov, I.G., Czigány, Zs. and Hultman, L. (2013) Reactive High Power Impulse Magnetron Sputtering of CFx Thin Films in Mixed Ar/CF4 and Ar/C4F8 Discharges. Thin Solid Films, 542, 21-30. http://dx.doi.org/10.1016/j.tsf.2013.05.165
Crassous, I., Groult, H., Lantelme, F., Devilliers, D., Tressaud, A., Labrugère, C., Dubois, M., Belhomme, C., Colisson, A. and Morel, B. (2009) Study of the Fluorination of Carbon Anode in Molten KF-2HF by XPS and NMR Investigations. Journal of Fluorine Chemistry, 130, 1080-1085. http://dx.doi.org/10.1016/j.jfluchem.2009.07.022
Liu, G., Sun, C., Cheng, L., Jin, Y., Lu, H., Wang, L., Smith, S.C., Lu, G.Q. and Cheng, H.-M. (2009) Efficient Promotion of Anatase TiO2 Photocatalysis via Bifunctional Surface-Terminating Ti-O-B-N Structures. The Journal of Physical Chemistry C, 113, 12317-12324. http://dx.doi.org/10.1021/jp900511u
Chiang, C.Y., Reddy, M.J. and Chu, P.P. (2004) Nano-Tube TiO2 Composite PVdF/LiPF6 Solid Membranes. Solid State Ionics, 175, 631-635. http://dx.doi.org/10.1016/j.ssi.2003.12.039
Yang, G., Wang, T., Yang, B., Yan, Z., Ding, S. and Xiao, T. (2013) Enhanced Visible-Light Activity of F-N Co-Doped TiO2 Nanocrystals via Nonmetal Impurity, Ti3+ Ions and Oxygen Vacancies. Applied Surface Science, 287, 135-142. http://dx.doi.org/10.1016/j.apsusc.2013.09.094
Li, Y., Jiang, Y., Peng, S. and Jiang, F. (2010) Nitrogen-Doped TiO2 Modified with NH4F for Efficient Photocatalytic Degradation of Formaldehyde under Blue Light-Emitting Diodes. Journal of Hazardous Materials, 182, 90-96. http://dx.doi.org/10.1016/j.jhazmat.2010.06.002
Fan, J.C.C. and Goodenough, J.B. (1977) X-Ray Photoemission Spectroscopy Studies of Sn-Doped Indium-Oxide Films. Journal of Applied Physics, 4B, 3524-3531. http://dx.doi.org/10.1063/1.324149
Sato, Y., Akizuki, H., Kamiyama, T. and Shigesato, Y. (2008) Transparent Conductive Nb-Doped TiO2 Films Deposited by Direct-Current Magnetron Sputtering using a TiO2-x Target. Thin Solid Films, 516, 5758-5762. http://dx.doi.org/10.1016/j.tsf.2007.10.047
Yu, C.-F., Sun, S.-J. and Chen, J.-M. (2014) Magnetic and Electrical Properties of TiO2:Nb Thin Films. Applied Surface Science, 292, 773-776. http://dx.doi.org/10.1016/j.apsusc.2013.12.047
Weisssmann, S., et al. (1978) Selected Powder Diffraction Data for Metals and Alloys. JCPDS, Card No. 21-1272, 263.