Optical Properties of TiO2 Films Deposited by Reactive Electron Beam Sputtering

Кручинин, В. Н.; Перевалов, Т. В.; Atuchin, Victor V.; Gritsenko, V. A.; Komonov, A. I.; Korolkov, Ilya V.; Pokrovsky, L.D.; Shih, C. W.; Chin, Albert

doi:10.1007/s11664-017-5552-3

Cited by 40 publications

(11 citation statements)

References 57 publications

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“…Its main advantages are its optical properties (a high refractive index, and transparency in the visible and NIR range) and its mechanical, physical and chemical properties (photocatalytic properties). The advantages of depositing TiO 2 coatings in the form of thin films have been demonstrated in many fields, including energy [ 11 ], photocatalysis [ 12 , 13 , 14 , 15 , 16 , 17 ], electronics [ 18 , 19 ], health [ 20 ], and optics [ 21 , 22 , 23 ]. Additionally, the coatings can be micro-nanostructured, thereby giving them new functionalities and properties, e.g., improved absorption efficiency [ 24 ], hydrophobicity and enhanced tribological properties [ 25 ].…”

Section: Introductionmentioning

confidence: 99%

Influence of the Micro-Nanostructuring of Titanium Dioxide Films on the Photocatalytic Degradation of Formic Acid under UV Illumination

et al. 2022

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Surface micro-nanostructuring can provide new functionalities and properties to coatings. For example, it can improve the absorption efficiency, hydrophobicity and/or tribology properties. In this context, we studied the influence of micro-nanostructuring on the photocatalytic efficiency of sol-gel TiO2 coatings during formic acid degradation under UV illumination. The micro-nanostructuring was performed using the UV illumination of microspheres deposited on a photopatternable sol-gel layer, leading to a hexagonal arrangement of micropillars after development. The structures and coatings were characterized using Raman spectroscopy, ellipsometry, atomic force microscopy and scanning electron microscopy. When the sol-gel TiO2 films were unstructured and untreated at 500 °C, their effect on formic acid’s degradation under UV light was negligible. However, when the films were annealed at 500 °C, they crystallized in the anatase phase and affected the degradation of formic acid under UV light, also depending on the thickness of the layer. Finally, we demonstrated that surface micro-nanostructuring in the form of nanopillars can significantly increase the photocatalytic efficiency of a coating during the degradation of formic acid under UV light.

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Section: Introductionmentioning

confidence: 99%

Influence of the Micro-Nanostructuring of Titanium Dioxide Films on the Photocatalytic Degradation of Formic Acid under UV Illumination

et al. 2022

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“…However, despite comparable ionic radii and electronegativity, studies available in the literature on the W-incorporated Ga 2 O 3 thin films reported on that amorphization occurs even for relatively lower W content and complete solid solution is possible only for a limited W concentration. , It must be noted that the ability to tune the processing conditions, particularly the deposition temperature required to produce crystalline materials in either chemical (CVD) or physical vapor deposition (PVD) methods of thin film fabrication, is limited. Furthermore, the CVD and PVD methods rely on nonequilibrium processes, where energetic ions will be taking part in thin film material production. − Therefore, the true solubility limits of the compound material system and required processing temperatures required may not reflect the efficient means to understand the fundamental limits of solid solution formation. On the other hand, the high-temperature solid-state chemical reaction method is a simple, versatile method to produce chemical compounds, where the solubility limits and component mixtures can be easily understood and/or manipulated.…”

Section: Introductionmentioning

confidence: 99%

Interplay between Solubility Limit, Structure, and Optical Properties of Tungsten-Doped Ga₂O₃ Compounds Synthesized by a Two-Step Calcination Process

et al. 2019

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This work unfolds the fundamental mechanisms and demonstrates the tunable optical properties derived via chemical composition tailoring in tungsten (W)-doped gallium oxide (Ga 2 O 3 ) compounds. On the basis of the detailed investigation, the solubility limits of tungsten (W 6+ ) ion and associated effects on the crystal structure, morphology, and optical properties of W-doped Ga 2 O 3 (Ga 2−2x W x O 3 , 0.00 ≤ x ≤ 0.25, GWO) compounds are reported. GWO materials were synthesized via a conventional solid-state reaction route, where a two-step calcination is adopted to produce materials with a high structural and chemical quality. X-ray diffraction analyses of sintered GWO compounds reveal the formation of a solid solution of GWO compounds at lower concentrations W (x ≤ 0.10), while unreacted WO 3 secondary phase formation occurs at higher concentrations (x>0.10). Insolubility of W at higher concentrations (x ≥ 0.15) is attributed to the difference in formation enthalpies of respective oxides, i.e., Ga 2 O 3 and WO 3 . GWO compounds exhibit an interesting trend in morphology evolution as a function of W content. While intrinsic Ga 2 O 3 exhibits rod-shaped morphology, W-doped Ga 2 O 3 compounds exhibit nearly spherical-shaped grain morphology. Increasing W content (x ≥ 0.10) induces morphology transformation from spherical to faceted grains with different facets (square and hexagonal). Relatively larger grain sizes in GWO compounds might be attributed to vacancy assisted enhanced mass transport due to W incorporation and/or WO 3 induced liquid phase sintering. Our findings demonstrate a substantial red shift in band gap (E g ), which is evident from the optical absorption spectra, enabling the wide spectral selectivity of GWO compounds. W 5d orbitals induced sp−d exchange interaction between valence band and conduction band electrons accounts for the substantial red shift in E g of GWO compounds. Also, with increasing W, E g decreases linearly, obeying Vegard law up to x = 0.15 and, at this point, an abrupt E g drop prevails. The nonlinearity (bowing ef fect) behavior in E g beyond x = 0.15 is due to insolubility of W at higher concentrations. The fundamental scientific understanding of the interdependence of synthetic conditions, structure, chemistry, and band gap could be useful to optimize GWO materials for optical, optoelectronic, and photocatalytic device applications.

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“…Ab initio моделирование атомной и электронной структуры SiO x <2 осуществлялось в программном пакете Quantum ESPRESSO в рамках теории функционала плотности (ТФП) для модели периодических суперячеек [15]. В расчетах использовался гибридный обменно-корреляционный функционал параметризации B3LYP, обеспечивающий корректное значение ширины запрещенной зоны high-k-диэлектриков [16,17]. Волновые функции валентных электронов (Si 3s 2 3p 2 и O 2s 2 2p 4 ) раскладывались по базису из плоских волн с энергией отсечки 950 eV, остов учитывался через сохраняющие норму псевдопотенциалы.…”

Section: материалы и методыunclassified

Оптические свойства нестехиометрического оксида кремния SiO-=SUB=-x-=/SUB=- (x<2)

Кручинин¹,

Перевалов²,

Камаев³

et al. 2019

Журнал Технической Физики

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The optical properties of amorphous nonstoichiometric silicon oxide (SiO_ x ) films of variable composition ( x = 0 . 62–1 . 92) formed by plasma-enhanced chemical vapor deposition are studied in the spectral range of 1 . 12–4 . 96 eV. Spectral ellipsometry showed that the refractive index dispersion character allows one to assign the formed SiO_ x films to silicon-like films, dielectrics, or intermediate-conductivity-type films depending on the content of oxygen in the gas phase during synthesis. A model of the SiO_ x structure for ab initio calculations is proposed and describes well the experimental optical spectra. Ab initio calculations of the dependences of the SiO_ x refractive index and band gap on stoichiometry parameter x are performed.

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Optical Properties of TiO2 Films Deposited by Reactive Electron Beam Sputtering

Cited by 40 publications

References 57 publications

Influence of the Micro-Nanostructuring of Titanium Dioxide Films on the Photocatalytic Degradation of Formic Acid under UV Illumination

Influence of the Micro-Nanostructuring of Titanium Dioxide Films on the Photocatalytic Degradation of Formic Acid under UV Illumination

Interplay between Solubility Limit, Structure, and Optical Properties of Tungsten-Doped Ga₂O₃ Compounds Synthesized by a Two-Step Calcination Process

Оптические свойства нестехиометрического оксида кремния SiO-=SUB=-x-=/SUB=- (x<2)

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Optical Properties of TiO2 Films Deposited by Reactive Electron Beam Sputtering

Cited by 40 publications

References 57 publications

Influence of the Micro-Nanostructuring of Titanium Dioxide Films on the Photocatalytic Degradation of Formic Acid under UV Illumination

Influence of the Micro-Nanostructuring of Titanium Dioxide Films on the Photocatalytic Degradation of Formic Acid under UV Illumination

Interplay between Solubility Limit, Structure, and Optical Properties of Tungsten-Doped Ga2O3 Compounds Synthesized by a Two-Step Calcination Process

Оптические свойства нестехиометрического оксида кремния SiO-=SUB=-x-=/SUB=- (x&lt;2)

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Interplay between Solubility Limit, Structure, and Optical Properties of Tungsten-Doped Ga₂O₃ Compounds Synthesized by a Two-Step Calcination Process

Оптические свойства нестехиометрического оксида кремния SiO-=SUB=-x-=/SUB=- (x<2)