Electrical Properties of Nb-Doped TiO2 Thin Films Deposited by Co-sputtering Process
Main Article Content
Abstract
Nb-doped Ti thin films were fabricated by co-sputtering of TiO2 doped 6 at% by Nb2O5 and Nb targets. The anatase polycrystalline thin films were obtained by post-annealing at 350oC in vacuum atmosphere. The electrical properties of the films were determined by the Hall method using standard clove-leaf geometry. When the Nb concentration increased, the number of electron increased from 4×1018 cm-3 to 2.4×1020 cm-3, while the resistivity fell down from 10 to 3.5×10-3 Ωcm. It means that this co-sputtering process can be considered as a method to improve conducting properties of Nb:Ti thin films. With low resistivity and high optical transmittance (higher than 80% in the visible range), the fabricated thin films can be applicable for transparent electrodes or heat-resistant coating.
Keywords: Nb-doped TiO2, co-sputtering method, transparent conducting
Keywords:
Nb-doped TiO2, co-sputtering method, transparent conducting
References
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[3] R. D. Gordon, Criteria for Choosing Transparent Conductors, MRS Bulletin 25 (2000) 52
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[6] N. L. H. Hoang, N. Yamada, T. Hitosugi, J. Kasai, S. Nakao, T. Shimada, and T. Hasegawa, Low-temperature Fabrication of Transparent Conducting Anatase Nb-doped TiO2 Films by Sputtering, Appl. Phys. Express 1 (2008) 115001
[7] D. S. Bhachu, S.Sathasivam, G.Sankar, D. O. Scanlon, G. Cibin, C. J. Carmalt, I. P.Parkin,G. W. Watson, S. M. Bawaked, A. Y. Obaid, S. Al-Thabaiti, and S. N. Basahel, Solution Processing Route to Multifunctional Titania Thin Films: Highly Conductive and Photcatalytically Active Nb:TiO2, Adv. Funct. Mater. 24 (2014) 5075
[8] S.Seegera, K.Ellmerb, M.Weisea, D.Gogovac, D.Abou-Rasb, and R.Mientusa, Reactive magnetron sputtering of Nb-doped TiO2 films: Relationships between structure, composition and electrical properties, Thin Solid Films 605 (2016) 44.
[9] J. Osorio-Guillen, S. Lany, and A. Zunger, Atomic Control of Conductivity Versus Ferromagnetism in Wide-Gap Oxides Via Selective Doping: V, Nb, Ta in Anatase TiO2, Phys. Rev. Lett.100 (2008) 036601.
[10]G. E. Jellison, L. A. Boatner, J. D. Budai, B. S. Jeong and D. P. Norton, Spectroscopic ellipsometry of thin film and bulk anatase (TiO2), J. Appl. Phys. 93 (2003) 9537
[11] B. H. Park, L. S. Li, B. J. Gibbons, J. Y. Huang and Q. X. Jia, Photovoltaic response and dielectric properties of epitaxial anatase TiO2 films grown on conductive La0.5Sr0.5CoO3 electrodes, Appl. Phys. Lett. 79 (2001) 2797
[12] M. Kambe, K. Sato, D. Kobayashi, Y. Korogawa, S. Miyajima, M. Fukawa, N. Taneda, A. Yamada and M. Konagai, TiO2-Coated Transparent Conductive Oxide (SnO2:F) Films Prepared by Atmospheric Pressure Chemical Vapor Deposition with High Durability against Atomic Hydrogen, Jpn. J. Appl. Phys.45 (2006) L291
[13] H. Nogawa, T. Hitosugi, H. Kamisaka, K. Yamashita, A. Chikamatsu, K. Yoshimatsu, H. Kumigashira, M. Oshima, S. Nakao, Y. Furubayashi, Y. Hirose, T. Shimada, and T. Hasegawa, Carrier Compensation Mechanism of Highly Conductive Anatase Ti0.94Nb0.06O2Epitaxial Thin Films, Mater. Res. Soc. Symp. Proc.1074 (2008) 1074-I05-08.
[14] T. Hitosugi, A. Ueda, S. Nakao, N. Yamada, Y. Furubayashi, Y. Hirose, T. Shimada, and T. Hasegawa, Fabrication of highly conductive Ti1−xNbxO2 polycrystalline films on glass substrates via crystallization of amorphous phase grown by pulsed laser deposition, Appl. Phys. Lett. 90 (2007) 212106
[15] N. Yamada, T. Hitosugi, J. Kasai, N. L. H. Hoang, S. Nakao,Y. Hirose, T. Shimada, and T. Hasegawa, Transparent conducting Nb-doped anatase TiO2 (TNO) thin films sputtered from various oxide targets, Thin Solid Films 518 (2010) 3101.
[16] N. Yamada, T. Hitosugi, J. Kasai, N. L. H. Hoang, S. Nakao. Y. Hirose, T. Shimada and T. Hasegawa, Direct growth of transparent conducting Nb-doped anatase TiO2 polycrystalline films on glass, J. Appl. Phys. 105 (2009) 123702
[17] D. Mardare, M. Tasca, M. Delibas and G.I. Rusu, On the structural properties and optical transmittance of TiO2 r.f. sputtered thin films, Appl. Surf. Sci 156 (2000) 200.
[18] M. Dobromir, R. Apetrei, A. V. Rogachev, D. L. Kovalenko and D. Luca1, Synthesis and Characterization of Nb-Doped TiO2 Thin Films Prepared by RF Magnetron Sputtering, Adv. Mater. Res. 1117 (2015) 139