116 research outputs found
Electrochemical deposition of zinc oxide on a thin nickel buffer layer on silicon substrates
No full textElectrochemical deposition of ZnO from aqueous nitrate solutions on nickel and platinum electrodes was investigated using the voltammetry technique to determine the optimal regimes in both potentiostatic and galvanostatic modes for acquiring polycrystalline ZnO films. Scanning electron microscopy, X-ray diffractometry, and X-ray microanalysis of the formed ZnO films are presented, showing a polycrystalline structure of the ZnO films with a preferable orientation in the (0 0 0 2) direction and an exact stoichiometric composition. The deposited ZnO films demonstrate a strong visible yellow-greenish photoluminescence at room temperature with a maximum at 600 um that can be referred to crystal lattice oxygen defects. The maximum of the photoluminescence excitation spectrum at 370 nm corresponds to the band gap of ZnO (3.3-3.35 eV) confirming that band-to-band excitation mechanism takes place. (C) 2011 Elsevier Ltd. All rights reserved
Visible Photoluminescence of Zinc Oxide Films Electrochemically Deposited on Silicon Substrates
No full textContinuous crystalline films of zinc oxide (ZnO) with thicknesses of 6-10 mu m were obtained by electrochemical deposition from aqueous zinc nitrate solutions on silicon substrates with a buffer nickel layer. X-ray diffraction measurements showed that the polycrystalline films possess a hexagonal crystal lattice with predominant (0002) orientation. The obtained ZnO films exhibit strong photoluminescence in the visible spectral range at room temperature
Electrochemical and hydrothermal deposition of ZnO on silicon: from continuous films to nanocrystals
No full textThis 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
ZnO films and crystals on bulk silicon and SOI wafers: Formation, properties and applications
No full textIn present work the investigation of the electrochemical and chemical hydrothermal deposition processes of ZnO on silicon is presented. The influence of the electrochemical process parameters on the characteristics and morphology of the ZnO deposits is analyzed. Electrochemical deposition from non aqueous DMSO solutions on porous silicon buffer layer is also discussed. The details of the chemical hydrothermal deposition from the nitrate bath of high-quality ZnO crystals on silicon substrate are presented. It was shown that morphology and size of synthesized ZnO crystals depends on the temperature of the deposition bath. Differences between photoluminescence of electrochemically deposited ZnO thin films and hydrothermally synthesized crystals are shown. Electrochemically deposited ZnO films demonstrate defect-caused luminescence and hydrothermally grown ZnO crystals shows intensive exciton luminescence band in UV region. Hydrothermal deposition of high-quality ZnO crystals on the surface of electrochemically deposited ZnO seed layer with porous silicon buffer improves photoluminescence properties of the structure which is useful for optoelectronics applications. Possible applications of ZnO as gas sensors and photovoltaic devices are considered. Aspects of ZnO electrochemical deposition on bulk silicon and silicon-on-isolator wafers for integration purposes are discussed
Determining the Project Model for Implementation ERP Class Information System for the Resurses and Activities Management in Territorial Communities
No full textO. P. Kopishynska, Y. V. Utkin, O.V. Kalashnik, S. E. Moroz, V. M. Chubenko. Determining the Project Model for Implementation ERP Class Information System for the Resurses and Activities Management in Territorial Communities. Інформаційні технології в енергетиці та агропромисловому комплексі: Матеріали ХІІ Міжнар. Наук. Конференції (Львів, 04-06 жовтня 2023 р.) / ЛНУП: за заг. ред. В. В. Снітинського. Львів: ЛНУП, 2023. C. 86-87.The paper presents a case study on the preparation of a pilot project for the implementation of ERP system modules for managing the resources and activities of the territorial community. Based on the study of the structure and activity of territorial communities, the uniqueness of such a solution for non- industrial organizations is revealed. Results of the survey of specialists and the content of the work at the project initiation stage are summarized
Determining the Project Model for Implementation ERP Class Information System for the Resurses and Activities Management in Territorial Communities
No full textO. P. Kopishynska, Y. V. Utkin, O.V. Kalashnik, S. E. Moroz, V. M. Chubenko. Determining the Project Model for Implementation ERP Class Information System for the Resurses and Activities Management in Territorial Communities. Інформаційні технології в енергетиці та агропромисловому комплексі: Матеріали ХІІ Міжнар. Наук. Конференції (Львів, 04-06 жовтня 2023 р.) / ЛНУП: за заг. ред. В. В. Снітинського. Львів: ЛНУП, 2023. C. 86-87.The paper presents a case study on the preparation of a pilot project for the implementation of ERP system modules for managing the resources and activities of the territorial community. Based on the study of the structure and activity of territorial communities, the uniqueness of such a solution for non- industrial organizations is revealed. Results of the survey of specialists and the content of the work at the project initiation stage are summarized
ГИДРОТЕРМАЛЬНОЕ ОСАЖДЕНИЕ НАНОКРИСТАЛЛОВ ОКСИДА ЦИНКА НА КРЕМНИЕВЫЕ ПОДЛОЖКИ
No full textResults of hydrothermal deposition of undoped and Al doped ZnO nanocrystals on a single-crystal silicon wafers with a hydrogen passivated surface are presented. Hydrothermal deposition of undoped ZnO nanocrystals were carried-out in a equimolar solutions containing zinc nitride Zn(NO3)2 and hexamethylenetetramine C6H12N4. Aluminum nitride Al(NO3)3 were used as Al precursor during deposition of Al doped ZnO nanocrystals. The difference of the morphology of doped and undoped ZnO nanocrystals was shown. Photoluminescence properties of the doped and undoped ZnO nanocrystals were also studied.Представлены результаты гидротермального осаждения нелегированных и легированных алюминием нанокристаллов оксида цинка на монокристаллические кремниевые подложки, поверхность которых была пассивирована водородом. Процесс гидротермального осаждения оксида цинка проводился в эквимолярных растворах нитрата цинка и гексаметилентетрамина. Нитрат алюминия был использован в качестве источника ионов алюминия для осаждения легированных кристаллов оксида цинка. В работе показано различие в морфологии нелегированных и легированных кристаллов оксида цинка. Исследованы спектры фотолюминесценции нелегированных и легированных алюминием кристаллов оксида цинка
Physicochemical properties of eutonic aqueous solutions of zinc and copper tetraammoniates in the range 293–323 K
No full textScaling violation in the fragmentation region of inclusive nucleon spektrum
No full textSpectra of cosmic ray showers associated with hadrons of various energies from 5 to 80 TeV were investigated. Results could be interpreted as scaling violation in the fragmentation region of secondary particles generated in inelastic interactions of primary protons at the energy above 30 TeV
Electrochemical deposition of zinc selenide and cadmium selenide onto porous silicon from aqueous acidic solutions
No full textStudy of structural, optical and photocatalytic properties of multilayered (1–8 layers) zinc oxide films deposited on glass substrates by sol-gel method showed, that after thermal treatment at 500°C they consist of random oriented hexagonal crystalline grains with size of 34–40 nm, forming larger particles with sizes of 100–150 nm, which do not depend on number of layers. With an increase in the number of layers, the intensity of exciton photoluminescence decreases by a factor of 10, the absorption of light in the visible and near IR ranges increases, and the efficiency of photocatalytic decomposition of the test organic dye rhodamine B increases by 10–12%. The observed changes are related to the increase in the total area of grain boundaries and to the change in the integral amount of oxygen vacancies and interstitial atoms as the number of layers increases, which makes it possible to control the properties of zinc oxide films for applications in optoelectronics, photovoltaics and photocatalysis
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