Improving the electrical properties of niobium-doped titania sputtering targets by sintering in oxygen-deficient atmospheres

Wu, Ming-Wei; Chang, Ching-Huai; Chen, Yan-Chi

doi:10.1016/j.ceramint.2015.03.116

Cited by 5 publications

(1 citation statement)

References 26 publications

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“…The value of the resistivity ρ at room temperature is 1 order of magnitude higher than reported values for reduced titania of roughly 10 −2 Ωcm. 22,23 In the heating curve, a small plateau can be observed at approximately 430 K. As will be shown later, the most appropriate conductivity model changes permanently from Mott's three-dimensional (3D) variable range hopping (VRH) model to the small polaron hopping (SPH) model the first time the as-deposited thin films are heated up to this temperature region. Extended thermal treatment at 430 K or higher temperatures leads to a permanent material property change in not only the resistivity but also the Seebeck coefficient and optical absorption coefficient.…”

Section: ■ Results and Discussionmentioning

confidence: 94%

Large Effect of Temperature Cycling on the Electrical and Optical Properties of TiO₂:H Thin Films

Glamsch

Karl

2023

J. Phys. Chem. C

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In this study, hydrogenated titanium dioxide (TiO 2 :H) thin films of thicknesses between 33 and 300 nm were grown via the reactive radiofrequency magnetron sputter deposition technique. These thin films were characterized with respect to electrical resistivity, Seebeck coefficient, and optical absorption coefficient. However, heating to temperatures above 430 K results in irreversible property changes of the thin films. The characteristics of these changes depended on the atmosphere, in which the samples were thermally treated (10 −7 mbar vacuum or 1 bar of 99.99% N 2 ). In order to explain these findings, we investigated our samples not only in the asdeposited state but also after thermal cycling over different temperature ranges. Mott's three-dimensional (3D) variable range hopping model was identified as the most appropriate electrical conductivity model in the asdeposited state for the temperature range of 223−430 K, after which it changes irreversibly to the small polaron hopping model in the 223−615 K temperature range. This thermally induced change appears to be due to changes in the number of intrinsic (interstitial titanium Ti int , titanium vacancies V Ti , and oxygen vacancies V o ) and extrinsic (hydrogen dopants) defects in the material. Spectroscopic ellipsometry measurements support this assumption. For this, we developed a dielectric dispersion model for TiO 2 :H thin films, which combines the Cody−Lorentz model with an additional Lorentz oscillator. In the as-deposited state, an additional peak of the absorption coefficient appears at 1.3−1.4 eV, which disappears for samples thermally treated in N 2 atmosphere but is retained for samples thermally treated in vacuum.

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Section: ■ Results and Discussionmentioning

confidence: 94%

Large Effect of Temperature Cycling on the Electrical and Optical Properties of TiO₂:H Thin Films

Glamsch

Karl

2023

J. Phys. Chem. C

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Thermoelectric properties of Nb-doped TiO2- ceramics reduced at elevated temperature

Yuan

et al. 2017

Ceramics International

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Synthesis mechanism and electrical conductivity of NbC O1- solid solution

Jiang,

Zhao,

Zhang

et al. 2024

Ceramics International

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Improving the electrical properties of niobium-doped titania sputtering targets by sintering in oxygen-deficient atmospheres

Cited by 5 publications

References 26 publications

Large Effect of Temperature Cycling on the Electrical and Optical Properties of TiO₂:H Thin Films

Large Effect of Temperature Cycling on the Electrical and Optical Properties of TiO₂:H Thin Films

Thermoelectric properties of Nb-doped TiO2- ceramics reduced at elevated temperature

Synthesis mechanism and electrical conductivity of NbC O1- solid solution

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Improving the electrical properties of niobium-doped titania sputtering targets by sintering in oxygen-deficient atmospheres

Cited by 5 publications

References 26 publications

Large Effect of Temperature Cycling on the Electrical and Optical Properties of TiO2:H Thin Films

Large Effect of Temperature Cycling on the Electrical and Optical Properties of TiO2:H Thin Films

Thermoelectric properties of Nb-doped TiO2- ceramics reduced at elevated temperature

Synthesis mechanism and electrical conductivity of NbC O1- solid solution

Contact Info

Product

Resources

About

Large Effect of Temperature Cycling on the Electrical and Optical Properties of TiO₂:H Thin Films

Large Effect of Temperature Cycling on the Electrical and Optical Properties of TiO₂:H Thin Films