Перегляд за Автор "Doicho, Ihor K."
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Документ An Interferometric Method of Inner surface Morphology Investigation in Porous Glass(Одеський національний університет імені І. І. Мечникова, 2005) Gevelyuk, Serhii A.; Doicho, Ihor K.; Mak, Vasyl T.; Safronsky, E. D.; Vorobyova, V. A.A method of inner surface morphology investigation in porous glass using modified Michelson’s interferometer is presented. The possibility of residual silica gel detection in pores by interferometric measurements is shown. The method also allows to distinguish the role of compressing and stretching forces in the mechanical deformation of porous samples. The proposed method is convenient to study the effect of additional treatments on the removal of residual silica gel out of porous glasses. Interferometric measurements make it possible to minimize the mechanical deformations of a porous layer on a solid substrate by tuning the layers thickness ratio.Документ Dependence of photoluminescence of nanoparticle ensembles of stannum (IV) complexes in silica porous matrix on concentration of saturating solution(Одеський національний університет імені І. І. Мечникова, 2016) Gevelyuk, Serhii A.; Rysiakiewicz-Pasek, E.; Doicho, Ihor K.; Гевелюк, Сергій Анатолійович; Ришякевич-Пасек, Е.; Дойчо, Ігор Костянтинович; Гевелюк, Сергей Анатольевич; Рысакевич-Пасек, Е.; Дойчо, Игорь КонстантиновичDependence of photoluminescence of high-molecular nanoformations of dyes on the basis of stannum (IV) complexes in porous glass on concentration of saturating solution has been researched. The results have been compared with photoluminescence of corresponding solutions, in which the effect of concentration quenching, was due to the Franck-Condon principle, was observed. It was found that intensity of luminescence for nanoparticle ensembles was always higher than in solution. At that, decrease of luminescence intensity alongside with concentration growth of saturating solution was observed as well. However, the observed dependence was more complicated than in solution. It can be explained by the fact that the pores with maximal sizes are filled at large concentrations of saturating solution of dye. The dye particles act almost the same as in solution, where photoluminescence is fainter, in such pores.Документ Gas sensitivity of some nanoparticles ensembles in porous glass(Одеський національний університет імені І. І. Мечникова, 2022) Doicho, Ihor K.; Filevska, Liudmila M.; Hrinevych, Viktor S.; Дойчо, Ігор Костянтинович; Філевська, Людмила Миколаївна; Гріневич, Віктор Сергійович; Дойчо, Игорь Константинович; Филевская, Людмила Николаевна; Гриневич, Виктор СергеевичThe importance of substances’ surface development suitable for sensor technology by dispersing them to the level of nanoparticles’ ensemble within a certain matrix has been demonstrated. It has been proven that the best matrix for the formation of the specified ensemble of nanoparticles is porous silicate glass. Methods of formation of ensembles of nanoparticles of some compounds in porous glass are briefly considered. The applicability of the mentioned systems for sensors is demonstrated by the example of their luminescent response sensitivity to the presence of ammonia or HCl vapours in the environment.Документ Influence of y-irradiation on photoluminescence of porous germanium obtained by treatment in electric spark discharge(Одеський національний університет імені І. І. Мечникова, 2001) Gevelyuk, Serhii A.; Doicho, Ihor K.; Kovalenko, M. P.; Lishchuk, D. E.; Mak, Vasyl T.; Prokopovich, L. P.; Chistyakov, V. P.The porous Ge layers are produced by spark discharge method. The photoluminescence spectra of these layers are compared with ones for porous Ge obtained by stain, chemical and electrochemical etching. There are the data in references that for porous Ge layers obtained by different methods the maximum for photoluminescence spectrum may be localized by two different wavelengths depending on the production procedure. In contrast to it, our spectra consist of both peaks. Using the results of photoluminescence spectra studies, the comparison of aging effects for porous Ge layers produced by different methods was made. The influence of у-quanta action on photoluminescence spectra of porous Ge layers was studied.Документ Photoluminescence and structural properties of nano-size CdS inclusions in porous glasses(Астропринт, 2007) Gevelyuk, Serhii A.; Doicho, Ihor K.; Mak, Vasyl T.; Zhukov, Serhii O.; Жуков, Сергій Олександрович; Жуков, Сергей АлександровичCadmium sulphide nanometer-formations in porous glass matrix are obtained. Results of electron-microscopic, XRD and EDS investigation of these formations are presented. The photoluminescence spectra of obtained samples are inves- tigated, and features of these spectra are explained.Документ Photoluminescence of tautomeric forms of nanoparticle ensembles of dyes based on the 4-valence stannum complexes in porous silica glass(Одесский национальный университете имени И. И. Мечникова, 2015) Doicho, Ihor K.; Gevelyuk, Serhii A.; Rysiakiewicz-Pasek, E.; Дойчо, Ігор Костянтинович; Гевелюк, Сергей Анатольевич; Ришякевич-Пасек, Е.; Дойчо, Игорь Константинович; Гевелюк, Сергій Анатолійович; Рысакеви-Пасек, Е.Luminescence of tautomeric forms of dyes based on the 4-valence stannum complexes was researched. Symmetry of photoluminescence spectra of different tautomeric forms relative to direction of reading of atom positions in the hydrazide fragment was found clockwise or anti clockwise. It was determined that the illumination of nanoparticle ensembles of dyes in A-type porous silica glass is always more intensive than in appropriate solution. It was shown that the luminescence intensity of tautomeric forms increases, if the substituent comes nearer to the coordination set irrespective of type and nature of substituent and type of coordination set. At the same time, change of illumination energy of tautomeric forms depends on both type and nature of substituent and coordination set. The results were explained by the development of inner surface of matrix and also by the features of atom disposition in dye molecule and by interaction between them.Документ Porous glasses with CDS inclusions luminescence kinetics peculiarities(Астропринт, 2009) Doicho, Ihor K.; Gevelyuk, Serhii A.; Ptashchenko, Oleksandr O.; Rysiakiewicz-Pasek, E.; Zhukov, Serhii O.; Дойчо, Игорь Константинович; Гевелюк, Сергей Анатольевич; Птащенко, Александр Александрович; Рысакевич-Пасек, Е.; Жуков, Сергей Александрович; Дойчо, Ігор Костянтинович; Гевелюк, Сергій Анатолійович; Птащенко, Олександр Олександрович; Ришякевич-Пасек, Е.; Жуков, Сергій ОлександровичThe kinetics of the luminescence of porous glass with CdS inclusions was studied at liquid nitrogen temperature. It is shown that the luminescence decay curves after excitation switching-off are different for different types of glasses. For CdS in matrices with small enough pores, a short-time “flash” of the luminescence was observed after the excitation turn off. Additional doping of the samples with Na2S enhanced the “flash”. The flash intensity and duration depended on the exciting photons energy. The effect is interpreted by thermo-optical excitation of electrons. Исследована кинетика фотолюминесценции пористого стекла с включениями CdS при температуре жидкого азота. Показано, что кривые спада фотолюминесценции после выключения возбуждения различны для различных типов стёкол. Для CdS в матрицах с достаточно малыми порами наблюдалась кратковременная вспышка люминесценции после выключения возбуждения. Дополнительное насыщение образцов Na2S усиливало указанную вспышку. Интенсивность и длительность вспышки зависела от энергии возбуждающих фотонов. Эффект объяснён термооптическим возбуждением электронов. Досліджено кінетику люмінесценції шпаристого скла із вкрапленнями CdS при температурі рідкого азоту. Продемонстровано, що криві спаду люмінесценції після вимкнення збудження неоднакові для різних типів скла. Для CdS в матрицях з достатньо малими порами спостерігався короткочасний спалах люмінесценції після вимкнення збудження. Додаткове насичення зразків Na2S підсилювало зазначений спалах. Інтенсивність і тривалість спалаху залежала від енергії збуджуючих фотонів. Ефект пояснено термооптичним збудженням електронів.Документ Substrate Crystallographic Orientation Effect on Photoluminescent Properties of Porous Silicon(Одеський національний університет імені І. І. Мечникова, 2005) Gevelyuk, Serhii A.; Doicho, Ihor K.; Mak, Vasyl T.; Soloshenko, Viktor I.; Lelechenko, V. P.; Zherditska, Y. R.Etching duration and anodic current density dependences of intensity and maximum position of the photoluminescence spectra of porous silicon layers obtained by anodization of silicon wafer are investigated. The sizes of silicon nanoclusters formed during the anodization procedure are estimated. It is shown that the dependence of formed clusters sizes on etching conditions for porous layers is different for various crystallographic orientations of the substrate. The model explaining this feature at various speeds of porous layer frontal advance deep into silicon substrate is offered. Presented results may be used for optimization of etching conditions in order to obtain the porous silicon layers having the preset parameters.Документ The Radiation Peculiarities of Nanoscale SnO2 in a Porous Matrix(2020) Gevelyuk, Serhii A.; Гевелюк, Сергій Анатолійович; Hrinevych, Viktor S.; Гріневич, Віктор Сергійович; Doicho, Ihor K.; Дойчо, Ігор Костянтинович; Lepikh, Yaroslav I.; Лепіх, Ярослав Ілліч; Лепих, Ярослав Ильич; Filevska, Liudmila M.; Філевська, Людмила МиколаївнаThe features of luminescent properties of an ensemble of tin dioxide nanoparticles created inside various types of porous silicate glass matrices under various thermosynthesis conditions are studied. It was demonstrated that the highest intensity of radiative recombination is inherent to the system formed in finely porous silicate glass with residual silica gel in the pores. Silica gel in this case prevents the aggregation of SnO2 nanoparticles. For the all types of matrix, the luminescence energy is less than the fundamental SnO2 energy gap, which may indicate a trap-like luminescence character of these systems. It was established an occurrence of at least two types of recombination centers – acceptors close to the valence band. The luminescence intensity varies depending on the content of the precursor in the initial solution to obtain samples. Its maximum is observed at 5-7 % tin chloride in the initial solution. The specified method of ensemble creation corresponds to the greatest width of the luminescence spectral lines, which is inherent to the intensity of radiative recombination. The smallest width of the spectral line corresponds to large concentrations close to those at which the SnCl4 alcohol solution becomes a strong glass adhesive. At these concentrations the solution already begins to glue the silica gel particles, freeing up space for the further formation of aggregations after the thermosynthesis reaction. In this case, the aggregation is intensive. In ensembles of SnO2 nanoparticles created in porous glass depleted in silica gel, nonradiative recombination predominates due to leakage channels through aggregations formed during thermosynthesis in the absence of an insulating substance. The study results can be used to create luminescent gas sensors based on SnO2.Документ Наноструктуроване шпаристе силікатне скло як перспективний матеріал для сенсоріки (Огляд)(Одеський національний університет імені І. І. Мечникова, 2023) Дойчо, Ігор Костянтинович; Лепіх, Ярослав Ілліч; Doicho, Ihor K.; Lepikh, Yaroslav I.Огляд присвячено дослідженню можливостей використання шпаристих силікатних стекол у сенсориці. Зазначені речовини є перспективними через власну хімічну стійкість, механічну тривкість та значну розгорнутість внутрішньої поверхні шпарин. Завдяки особливостям своєї будови ці стекла можуть використовуватися як матриця для формування ансамблів наночастинок слушних речовин, які здатні утворити всередині шпаристого зразка провідну фазу.