15 results on '"Vitaly Bondarenko"'
Search Results
2. Effect of Microstructure and Performance of Nb–Cr–Fe–Ni Quaternary Alloys with the Variation of Niobium Element Content
- Author
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Honglian Deng, Linsen Li, Junjie Feng, Jiqiu Qi, Fuxiang Wei, Qingkun Meng, Yaojian Ren, Bin Xiao, Xiaolan Xue, Qing Yin, Yongzhi Li, Yanwei Sui, Xiujuan Feng, Wen Zhang, Peng Cao, Eugene B. Chubenko, and Vitaly Bondarenko
- Subjects
General Medicine - Published
- 2022
3. Enhanced performance of FeOOH/ZnIn2S4/Au nanosheet arrays for visible light water splitting
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Zhongyong Jiang, Kun Li, Xiaoyan Cai, Eugene Chubenko, Vitaly Bondarenko, Liang Mao, Yulong Zhao, and Xiuquan Gu
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Electrical and Electronic Engineering ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials - Published
- 2022
4. Method for determining bond energy in nanostructured water
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Sergey Redko, Svetlana Volchek, V. Petrovich, Vitaly Bondarenko, and V. Yakovtseva
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Electrolysis ,Materials science ,Properties of water ,Mechanical Engineering ,Relaxation (NMR) ,Activation energy ,Mechanics ,Contamination ,Condensed Matter Physics ,law.invention ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,law ,Electrode ,Dissipation factor ,General Materials Science ,Bond energy - Abstract
Using water as an example, it is shown that monitoring the change in the loss tangent is a high sensitive method that allows determining the activation energy of relaxation processes in nanostructured water with high accuracy. The use of sensors, the electrodes of which are not in direct contact with the liquid under study is shown to be reasonable. The conditions for obtaining reliable information on the properties of water and its solutions are also justified, namely: measurements should be carried out using pulse methods for several seconds, and then measurements should be stopped to avoid contamination of the solutions studied by electrolysis products. The method of monitoring the magnitude of the loss tangent at fixed frequencies allows the acidity of solutions (pH value) to be controlled at the same time without using specialized instruments for acidity studying.
- Published
- 2020
5. Photoluminescence of ZnO/C Nanocomposites Formed by the Sol-Gel Method
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E. B. Chubenko, Victor E. Borisenko, Vitaly Bondarenko, N. M. Denisov, and T. A. Shevtsova
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Nanocomposite ,Materials science ,Photoluminescence ,Exciton ,chemistry.chemical_element ,02 engineering and technology ,Zinc ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Chemical engineering ,chemistry ,Chlorine ,0210 nano-technology ,Carbon ,Spectroscopy ,Excitation ,Sol-gel - Abstract
Films of undoped zinc oxide (ZnO) and of ZnO/C nanocomposite were formed by the sol-gel method on glass substrates and on fiberglass using zinc acetate as a precursor and with the addition of zinc chloride respectively. Analysis of the photoluminescence spectra of ZnO/C films at high (N2-laser) and low (HeCd-laser) excitation levels made it possible to establish the defining role of bound excitons in this process at 20–60 K, due to the presence of chlorine residues in the films. With the temperature raised to 300 K the role of recombination through the 1LO- and 2LO-phonon replicas of free exciton levels and impurity-defect levels begins to dominate in the photoluminescence of the ZnO/C films.
- Published
- 2018
6. Express-Method for the Study of Electrolyte Anion Profiles in the Bulk of Dense Anodic Alumina Films
- Author
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Alexey Subko, Dimitry Shimanovich, Vitaly Sokol, V. Yakovtseva, and Vitaly Bondarenko
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Materials science ,Anodizing ,020209 energy ,Mechanical Engineering ,Oxide ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Anode ,Ion ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Mechanics of Materials ,Aluminium ,Etching ,0202 electrical engineering, electronic engineering, information engineering ,General Materials Science ,Electrolyte anion ,0210 nano-technology ,Electrode potential - Abstract
The procedure proposed is the express method for the study of anion distribution profiles in the anodic aluminum oxide film. The method consists in measuring the variation of the steady-state electrode potential during the oxide etching. It allows the influence of the initial aluminum composition, the electrolyte composition, anodization regimes, etc. on the characteristics of dense anodic alumina films to be studied. The method developed can be used to study a chemical evolution in anodic alumina formed to correlate with modelling and simulations across materials science disciplines.
- Published
- 2018
7. Black ZnO/C nanocomposite photocatalytic films formed by one-step sol–gel technique
- Author
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Vitaly Bondarenko, N. M. Denisov, E. B. Chubenko, and Victor E. Borisenko
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Nanocomposite ,Materials science ,Photoluminescence ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,Zinc ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Biomaterials ,chemistry ,Amorphous carbon ,Chemical engineering ,Materials Chemistry ,Ceramics and Composites ,Photocatalysis ,Surface layer ,0210 nano-technology ,Carbon ,Sol-gel - Abstract
We developed a facile one-step sol–gel technique for fabrication of black zinc oxide/carbon (ZnO/C) nanocomposite films demonstrating an enhanced photocatalytic activity. Amorphous carbon covering ZnO grains inside the films was reduced from organic components of the zinc acetate based sol calcinated at 500 °C. The amount of carbon in the films can be controlled by varying the amount of zinc chloride added to the zinc acetate based sols. The surface layer of the films is composed by randomly oriented hexagon-shaped ZnO grains. Photoluminescence quenching indicating the suppression of electron-hole recombination in the prepared ZnO/C composites were observed. The recorded optical transmittance/reflectance spectra and the performed photocatalytic tests demonstrated that the synthesized ZnO/C nanocomposite is promising for photoinduced decomposition of organic compounds. Related peculiarities are discussed.
- Published
- 2017
8. Morphology dependent optical properties of ZnO/SiNWs nanocomposites
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E. B. Chubenko, Vitaly Bondarenko, Aliaksandr Sharstniou, Stanislau Niauzorau, and Bruno Azeredo
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010302 applied physics ,Nanocomposite ,Nanostructure ,Materials science ,Annealing (metallurgy) ,business.industry ,Mechanical Engineering ,Heterojunction ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Isotropic etching ,Mechanics of Materials ,0103 physical sciences ,Electrode ,Optoelectronics ,General Materials Science ,Wafer ,Charge carrier ,0210 nano-technology ,business - Abstract
Zinc oxide/silicon nanowires (ZnO/SiNWs) nanocomposites is a promising material for heterojunction solar cells. They combine the low-reflectivity of SiNWs, where photogenerated charge carriers are produced and harvested, and the high transparency of ZnO, which serves as a functional transparent conductive electrode. In this paper, we present a study of the anti-reflective properties of ZnO/SiNWs core-shell nanostructures. SiNWs were fabricated by a two-step metal-assisted chemical etching and coated with ZnO by electrochemical deposition. Particularly, the change in the specular reflectance of ZnO/SiNWs nanocomposites as a function of thermal annealing temperature under ambient atmosphere is investigated. First, it was shown that the reflectance in the wavelength range of 400-1000 nm of as-synthesized ZnO/SiNWs nanocomposites increases when compared to the bare SiNWs formed from Si wafers with resistivity of 0.3 and 12 Ω∙cm by an 0.51 % and 0.47 %, respectively. Second, it was found that annealed ZnO/SiNWs had a 0.26 % and 0.17 % lower reflectance in the wavelength range of 400-1000 nm than as-synthesized ZnO/SiNWs and yet higher than bare SiNWs. Potential causes such results are discussed in the context of existing literature.
- Published
- 2017
9. Electrochemical and hydrothermal deposition of ZnO on silicon: from continuous films to nanocrystals
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Paolo Nenzi, E. B. Chubenko, Vitaly Bondarenko, Marco Balucani, and Alexy Klyshko
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Materials science ,Silicon ,Inorganic chemistry ,Nanocrystalline silicon ,chemistry.chemical_element ,Bioengineering ,Equivalent oxide thickness ,General Chemistry ,Zinc ,x-ray diffraction ,zinc oxide ,photoluminescence ,nanocrystal ,porous silicon ,Condensed Matter Physics ,Porous silicon ,Atomic and Molecular Physics, and Optics ,Surface coating ,Chemical engineering ,chemistry ,Modeling and Simulation ,General Materials Science ,Porous medium ,Layer (electronics) - Abstract
This article presents the study of the electrochemical deposition of zinc oxide from the non-aqueous solution based on dimethyl sulfoxide and zinc chloride into the porous silicon matrix. The features of the deposition process depending on the thickness of the porous silicon layer are presented. It is shown that after deposition process the porous silicon matrix is filled with zinc oxide nanocrystals with a diameter of 10–50 nm. The electrochemically deposited zinc oxide layers on top of porous silicon are shown to have a crystalline structure. It is also shown that zinc oxide crystals formed by hydrothermal method on the surface of electrochemically deposited zinc oxide film demonstrate ultra-violet luminescence. The effect of the porous silicon layer thickness on the morphology of the zinc oxide is shown. The structures obtained demonstrated two luminescence bands peaking at the 375 and 600 nm wavelengths. Possible applications of ZnO nanostructures, porous and continuous polycrystalline ZnO films such as gas sensors, light-emitting diodes, photovoltaic devices, and nanopiezo energy generators are considered. Aspects of integration with conventional silicon technology are also discussed.
- Published
- 2011
10. [Untitled]
- Author
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L. Dolgyi, V. Yakovtseva, Vitaly Bondarenko, G. Lamedica, L. Franchina, N. Vorozov, N. Kazuchits, Marco Balucani, and Aldo Ferrari
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Thermal oxidation ,Dielectric isolation ,Materials science ,Fabrication ,Anodizing ,business.industry ,Hybrid silicon laser ,Mechanical Engineering ,Electrolyte ,Chemical cleaning ,Porous silicon ,Mechanics of Materials ,Optoelectronics ,General Materials Science ,business - Abstract
A brief review of 20-years research of formation, processing and utilizing of oxidized porous silicon (OPS) is presented. Electrolytes to form porous silicon (PS) layers, special features of PS chemical cleaning and thermal oxidation are discussed. OPS application for dielectric isolation of components of bipolar ICs and for the formation of silicon-on-insulator structures has been demonstrated. Although these OPS-based techniques have found limited current commercial use, experience gained is applicable to the fabrication of optoelectronic devices. Specifically, integrated optical waveguides based on OPS have been developed.
- Published
- 2000
11. [Untitled]
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V. Yakovtseva, Leonid Tsybeskov, L. Dolgyi, Philippe M. Fauchet, N. Kazuchits, V. Petrovich, Vitaly Bondarenko, and S. Volchek
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Materials science ,Electrolysis of water ,Hydrogen ,Mechanical Engineering ,Inorganic chemistry ,chemistry.chemical_element ,Porous silicon ,Electrochemistry ,Reference electrode ,Cathode ,law.invention ,Secondary ion mass spectrometry ,Adsorption ,chemistry ,Mechanics of Materials ,law ,General Materials Science - Abstract
Electrochemical treatment of porous silicon (PS) in ethanol solution of Er(NO3)3 was investigated to obtain material suitable for optoelectronic application. The voltammograms of n+-type and p-type PS vs. an Ag/AgCl reference electrode were examined and compared with these of a Pt electrode. The basic cathode reactions were marked out the voltammograms: (i) the formation and the adsorption of atomic hydrogen; (ii) the formation of molecular hydrogen; (iii) the electrolysis of water and ethanol. No zones relating to on electrochemical transitions of Er ions were revealed on the voltammograms. Nevertheless, with the cathode polarization, the formation of an Er-containing deposit was observed at the surface of the cathode. The IR and SIMS analysis were used to study the composition of the deposits. The scheme of the electrochemical and chemical reactions at the cathode is discussed.
- Published
- 2000
12. [Untitled]
- Author
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G. Lamedica, L. Dolgyi, Aldo Ferrari, Marco Balucani, V. Yakovtseva, Vitaly Bondarenko, and L. Franchina
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Diffusion layer ,Morphology (linguistics) ,Materials science ,Mechanics of Materials ,N type silicon ,Mechanical Engineering ,General Materials Science ,Nanotechnology ,Effective surface ,Composite material ,Porous silicon ,Porosity ,Current density - Abstract
The properties of porous silicon (PS) are closely connected to its morphology, much investigation has been done in order to correlate the morphological characteristics of PS with the anodisation parameters. In this paper the results of morphological analysis of PS formed on N+type substrates of 〈1 0 0〉 and 〈1 1 1〉 orientation are presented. The dependences of the porosity, thickness of PS, density of pores and of the effective surface on the current density are obtained. Interpretation of these results in terms of diffusion layer and energy levels is given, with special attention given to the low current density case.
- Published
- 2000
13. White-light emission from porous-silicon-aluminum Schottky junctions
- Author
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Vitaly Bondarenko, Gianlorenzo Masini, G. Maiello, S. Lazarouk, and S. La Monica
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Fabrication ,Materials science ,Silicon ,business.industry ,Schottky barrier ,General Physics and Astronomy ,Schottky diode ,chemistry.chemical_element ,Semiconductor device ,Electroluminescence ,Porous silicon ,chemistry ,Optoelectronics ,Crystalline silicon ,business - Abstract
Porous-silicon-based white-light-emitting devices are presented. The fabrication process on different substrates is described. The peculiarities of technological steps for device fabrication (porous-silicon formation and aluminum treatment) are underlined. Doping profile of the porous layer, current-voltage characteristics, time response, lifetime tests and electroluminescence emission spectrum of the device are presented. A model for electrical behaviour of Al/porous silicon Schottky junction is presented. Electroluminescence spectrum of the presented devices showed strong similarities with white emission from crystalline silicon junctions in the breakdown region.
- Published
- 1996
14. Formation and Luminescent Properties of Oxidized Porous Silicon Doped with Erbium by Electrochemical Procedure
- Author
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G. F. Grom, L. Dolgyi, V. Yakovtseva, Herman A. Lopez, N. Kazuchits, Philippe M. Fauchet, V. Petrovich, Leonid Tsybeskov, Vitaly Bondarenko, N. Vorozov, and S. Volchek
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Materials science ,Photoluminescence ,Electrical resistivity and conductivity ,Doping ,Inorganic chemistry ,Analytical chemistry ,Photoluminescence excitation ,Partial oxidation ,Atmospheric temperature range ,Porous silicon ,Luminescence - Abstract
The present work is concerned with Er-doped oxidized porous silicon (PS). The characteristic feature of the work is that PS doping has been realized by an electrochemical procedure followed by a high temperature treatment. 5-μm thick PS layers were formed on p-type Si of 0.3-Ohm-cm resistivity. Er incorporation was performed by a cathodic polarization of PS in a 0.1 M Er(NO3)3 aqueous solution. A high temperature treatment in an oxidizing ambient at 500-1000°C was utilized to provide either partial or total oxidation of PS:Er layers. X-ray microanalysis was used to study chemical composition of the samples. Photoluminescence (PL) and photoluminescence excitation (PLE) spectra were investigated. After the partial oxidation (in the temperature range of 600-800°C), weak Er3+-related PL at 1.53 ptm was observed. A high temperature anneal in Ar atmosphere at the temperature of 1100°C caused a significant increase in the Er3+-related PL intensity. Resonant features were observed in PLE spectra of fully oxidized PS. Five peaks at 381, 492, 523, 654 and 980 nm were revealed. The strongest excitation occurred at 381 and 523 nm. The excitation of different Er3+ energy levels, cross-relaxation interactions and emission due to the 4I13/2→4I15/2 transitions were considered. Application of the Er-doped oxidized PS for integrated optical waveguides is presented.
- Published
- 1998
15. Integration of Multilayers in Er-Doped Porous Silicon Structures and Advances in 1.5 μm Optoelectronic Devices
- Author
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Hideki Koyama, Herman A. Lopez, Selena Chan, Philippe M. Fauchet, Vitaly Bondarenko, and Leonid Tsybeskov
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Materials science ,Photoluminescence ,Silicon ,business.industry ,Infrared ,Doping ,chemistry.chemical_element ,Electroluminescence ,Porous silicon ,Erbium ,chemistry ,Optoelectronics ,business ,Luminescence - Abstract
Infrared photoluminescence (PL) and electroluminescence (EL) from erbium-doped porous silicon (PSi) structures are studied. The PL and EL from the Er-doped PSi structures and the absence of silicon band edge recombination, point defect, and dislocation luminescence bands suggest that the Er-complex centers are the most efficient recombination sites. PSi multilayers with very high reflectivity (R ≥ 90%) in the 1.5 gim range have been incorporated in the structures resulting in a PL enhancement of over 100%. Stable and intense EL is obtained from the Er-doped structures. The EL spectrum is similar to that of the PL, but shifted towards higher energy. The unexpected shift in emission opens up the possibility for erbium related luminescence to encompass a larger part of the optimal wavelength window for fiber optic communications.
- Published
- 1998
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