Ta-doped Anatase TiO<sub>2</sub> Epitaxial Film as Transparent Conducting Oxide

Hitosugi, Taro; Furubayashi, Yutaka; Ueda, Atsuki; Itabashi, Kinnosuke; Inaba, Kazuaki; Hirose, Yasushi; Kinoda, Go; Yamamoto, Yukio; Shimada, Toshihiro; Hasegawa, Tetsuya

doi:10.1143/jjap.44.l1063

Cited by 160 publications

(132 citation statements)

References 12 publications

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“…Tantalum (Ta) was also considered because this metal is stable in harsh electrochemical environments and doping with this metal also improves titania's conductivity. 26,31 Both anatase and rutile phases of titania were studied. Nb-, Ru-, and Ta-doped titania were compared to undoped titania and to each other in the aspects of structure, partial and total density of states (DOS), and free energy of substitution.…”

Section: -12mentioning

confidence: 99%

Electronic Conductivity and Stability of Doped Titania (Ti_1−XM_XO₂, M = Nb, Ru, and Ta)—A Density Functional Theory-Based Comparison

Hui

Zhang

et al. 2010

J. Phys. Chem. C

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The structure, electrical conductivity, and stability of Nb-, Ru-, and Ta-doped titania were compared by density functional theory. Both anatase and rutile structures were investigated. Doping causes lattice expansion in all cases. The mechanism by which Ru-doping induces electrical conductivity in titania differs from those by Ta-and Nb-doping. Ru-doping fills the titania band gap primarily with its own d-electrons. On the other hand, Ta-and Nb-doping shift the Fermi level to the originally unfilled conduction states. Substitution free energy calculations indicate that a uniform Ti 0.75 M 0.25 O 2 solution is favorable for Nb-and Ta-doping but unfavorable for Ru-doping. In addition, we also considered the effect of dopant concentration on the electrical conductivity of doped titania in the rutile phase. For Nb-and Ta-doping, increasing dopant concentration above mole fractions of 0.0625 and 0.125, respectively, gives diminished increment in Fermi level electron density. On the other hand, electron density at the Fermi level of Ru-doped rutile is more linearly dependent on Ru mole fraction.

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Section: -12mentioning

confidence: 99%

Electronic Conductivity and Stability of Doped Titania (Ti_1−XM_XO₂, M = Nb, Ru, and Ta)—A Density Functional Theory-Based Comparison

Hui

Zhang

et al. 2010

J. Phys. Chem. C

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“…All of them have limitations such as uncomfortably narrow ranges of deposition parameters, requirements of high substrate temperatures, cost (for In), etc., and viable alternatives have been sought for many years. A recently discovered alternative is doped TiO 2 [3,4], which is different from the other TCOs in that conduction takes place in the d-band rather than in the s-band [5,6]. Earlier work on TCO-type TiO 2 :Nb has employed pulsed laser deposition [3,[7][8][9][10][11][12][13][14], rf magnetron sputtering [15], and dc magnetron sputtering [11,[16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Optical properties of sputter deposited transparent and conducting TiO2:Nb films

2009

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Transparent and conducting thin films of TiO 2 :Nb were prepared on glass by reactive dc magnetron sputtering in Ar + O 2 . Post deposition annealing in vacuum at 450 o C led to good electrical conductivity and optical transparency. The optical properties in the subbandgap region were in good agreement with Drude free electron theory, which accounts for intraband absorption. The band gap of the films was found to be in the range of 3.3 to 3.5 eV and signifies the onset of interband absorption. Electrical conductivities in the 10 -3

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“…TiO 2 -NFs are expected to have many connections to TiO 2 nanoparticles in DSCs without making high potential barrier of carriers at the interface. NTO is well known as TCO with high transparency and conductivity having the same crystal structure of anatase [6,7]. By doping Nb atoms, the Fermi energy of TiO 2 is lowered without any large distortion of crystal lattice.…”

Section: Introductionmentioning

confidence: 99%

Application of Electrospun Nb:TiO<sub>2</sub> Nanofibers to Dye Sensitized Solar Cells

Horie

Watanabe

Deguchi

et al. 2014

Trans. Mat. Res. Soc. Japan

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The electrospun nanofibers of TiO 2 and Nb doped TiO 2 (NTO) were mixed into the TiO 2 mesoporous layer in the photoelectrodes of dye sensitized solar cells (DSCs) as a conductive agent, and their effects to the carrier mobility and photovoltaic characteristics were examined. From the time-transient spectra of photocurrent excited by the pulse laser irradiation, it was found that the diffusive velocity of photoexcited carriers was increased by the mixture of the bundle of electrospun nanofibers, and the increase resulted in the improvement of short-circuit current density and efficiency. The enhancement of carrier mobility was also observed due to the band bending at the interface of NTO/TiO 2 . Thus, it was found that electrospun nanofibers of NTO were a good conductive agent for the accumulation of photoexcited carriers in dye/TiO 2 nanoparticles.

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Ta-doped Anatase TiO₂ Epitaxial Film as Transparent Conducting Oxide

Cited by 160 publications

References 12 publications

Electronic Conductivity and Stability of Doped Titania (Ti_1−XM_XO₂, M = Nb, Ru, and Ta)—A Density Functional Theory-Based Comparison

Electronic Conductivity and Stability of Doped Titania (Ti_1−XM_XO₂, M = Nb, Ru, and Ta)—A Density Functional Theory-Based Comparison

Optical properties of sputter deposited transparent and conducting TiO2:Nb films

Application of Electrospun Nb:TiO<sub>2</sub> Nanofibers to Dye Sensitized Solar Cells

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Ta-doped Anatase TiO2 Epitaxial Film as Transparent Conducting Oxide

Cited by 160 publications

References 12 publications

Electronic Conductivity and Stability of Doped Titania (Ti1−XMXO2, M = Nb, Ru, and Ta)—A Density Functional Theory-Based Comparison

Electronic Conductivity and Stability of Doped Titania (Ti1−XMXO2, M = Nb, Ru, and Ta)—A Density Functional Theory-Based Comparison

Optical properties of sputter deposited transparent and conducting TiO2:Nb films

Application of Electrospun Nb:TiO<sub>2</sub> Nanofibers to Dye Sensitized Solar Cells

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Ta-doped Anatase TiO₂ Epitaxial Film as Transparent Conducting Oxide

Electronic Conductivity and Stability of Doped Titania (Ti_1−XM_XO₂, M = Nb, Ru, and Ta)—A Density Functional Theory-Based Comparison

Electronic Conductivity and Stability of Doped Titania (Ti_1−XM_XO₂, M = Nb, Ru, and Ta)—A Density Functional Theory-Based Comparison