V. Simakov - Academia.edu (original) (raw)

Papers by V. Simakov

Russian Journal of Electrochemistry, 2005

Current-voltage curves for sensor structures based on thin tin oxide films are examined in variou... more Current-voltage curves for sensor structures based on thin tin oxide films are examined in various gases. Conditions favoring symmetrical nonlinear curves in the voltage range-30 to 30 V are found.

Abstract book of the 2nd International Scientific Conference "Plants and Microbes: the Future of Biotechnology" PLAMIC2020, 2020

The use of polymer films modified by plasma treatment is proposed as a carrier for immobilizing c... more The use of polymer films modified by plasma treatment is proposed as a carrier for immobilizing cells at create biosensors.

Nano- i Mikrosistemnaya Tehnika, 2017

Solid-state electrochemical cells containing an alkali metal/organic semiconductor direct contact... more Solid-state electrochemical cells containing an alkali metal/organic semiconductor direct contact are studied using a potentiodynamic method. Both ionic and electronic charge transfer processes are possible in heterostructures based on direct contact of alkali metals with p-type semiconductors. The multistage processes proceeding in the systems studied involve chemical reactions and changes in the resistance of both the initial cathode material and the cathodic reduction products.

Instruments and Experimental Techniques, 2009

Technical Physics Letters, 2006

Variation of the current-voltage (I-U) characteristics of thin-film gas sensors based on tin diox... more Variation of the current-voltage (I-U) characteristics of thin-film gas sensors based on tin dioxide (SnO 2) in the presence of various gases has been studied in a range of working temperatures from 200 to 450 ° C. The experimental I-U curves are interpreted assuming that various forms of adsorbed oxygen species are present on the tin dioxide surface and that the adsorbed ions can migrate over the surface with different mobilities. Features of the observed phenomena can be used for selecting working temperatures at which an analysis of the I-U curves can provide a basis for the identification of various species adsorbed on the same sensor.

Technical Physics Letters, 2006

Variation of the conductivity of a thin film of tin dioxide (SnO 2) in response to a stepwise cha... more Variation of the conductivity of a thin film of tin dioxide (SnO 2) in response to a stepwise change in the content of various impurities present in the gas phase has been studied in a broad range of concentrations. The experimental data are interpreted within the framework of the Roginskii-Elovich model of adsorption kinetics. A gas-pressure-independent parameter characterizing the sensor conductivity variation is established. Using the phenomenon under consideration, it is possible to identify adsorbed gas species.

Technical Physics, 1999

ABSTRACT The deposition of tin oxide films by reactive sputtering of a stoichiometric target is i... more ABSTRACT The deposition of tin oxide films by reactive sputtering of a stoichiometric target is investigated. Conditions are determined for the formation of a crystal layer structure and the acquisition of gas sensitivity without subsequent high-temperature annealing.

Russian Journal of Electrochemistry, 2007

Solid-state ionics, based on fast ionic transport in solids and characterized by anomalously larg... more Solid-state ionics, based on fast ionic transport in solids and characterized by anomalously large diffusion coefficients of ions at room temperature and unipolar conductivity (0.05–0.1 S cm−1), assumed in the last few years great importance in the context of creation and subsequent explanation of mechanisms and kinetics of electrode processes during the work of chemical power sources (CPS). It is demonstrated that products of cathodic reactions possess ionic conduction in a solid phase.

Sensors and Actuators B: Chemical, 2006

The nonlinearity of the current-voltage characteristics has been observed in thin films of the ti... more The nonlinearity of the current-voltage characteristics has been observed in thin films of the tin oxide exposed to strong electric fields. The experimental data are discussed assuming the drift-type behavior of the absorbed ions along the surface. The observed phenomena allow application for both air contamination detection and the contamination identification.

Physical and Chemical Aspects of the Study of Clusters, Nanostructures and Nanomaterials, Dec 15, 2017

Рецензирование статей осуществляется на основания Положения об рецензировании статей и материалов... more Рецензирование статей осуществляется на основания Положения об рецензировании статей и материалов для опубликования в Межвузовском сборнике научных трудов «Физико-химические аспекты изучения кластеров, наноструктур и наноматериалов». Официальный сайт издания в сети Интернет: www.physchemaspects.ru Ф50 Физико-химические аспекты изучения кластеров, наноструктур и наноматериалов [Текст]: межвуз. сб. науч. тр. / под общей редакцией

Applied Biochemistry and Microbiology, 2020

It is shown that microbial cells can be immobilized on polymer matrices modified via plasma treat... more It is shown that microbial cells can be immobilized on polymer matrices modified via plasma treatment. On the example of microbial cells Azospirillum brasilense Sp 7, A. lipoferum Sp59b, and Escherichia coli XL-1, it was found that the immobilization efficiency of biological objects depends on the film processing time in plasma. Treatment of a polystyrene film in a high-frequency discharge plasma allowed a significant increase in the lifetime of microbial cells immobilized on its surface. It was shown that the optimal time for film processing in plasma was 30 s, the time to immobilize microbial cells was ~ 20 min, and bacteria remained viable for up to 6 months after immobilization. The use of matrices modified with plasma treatment as a carrier for immobilized the microbial cells to production biosensors is proposed.

Physical and chemical aspects of the study of clusters, nanostructures and nanomaterials

Рецензирование статей осуществляется на основании Положения о рецензировании статей и материалов ... more Рецензирование статей осуществляется на основании Положения о рецензировании статей и материалов для опубликования в Межвузовском сборнике научных трудов «Физико-химические аспекты изучения кластеров, наноструктур и наноматериалов». Официальный сайт издания в сети Интернет: https://www.physchemaspects.ru Ф50 Физико-химические аспекты изучения кластеров, наноструктур и наноматериалов [Текст].  Тверь: Твер. гос. ун-т, 2019.  Вып. 11.  680 с. Зарегистрирован Федеральной службой по надзору в сфере связи, информационных технологий и массовых коммуникаций, свидетельство о регистрации СМИ ПИ № ФС 7747789 от 13.12.2011. Издание составлено из оригинальных статей, кратких сообщений и обзоров теоретического и экспериментального характера, отражающих результаты исследований в области изучения физико-химических процессов с участием кластеров, наноструктур и наноматериалов физики, включая межфазные явления и нанотермодинамику. Сборник предназначен для научных и инженерно-технических работников, преподавателей ВУЗов, студентов и аспирантов. Издание подготовлено на кафедре общей физики Тверского государственного университета. Переводное название: Physical and chemical aspects of the study of clusters, nanostructures and nanomaterials Транслитерация названия: Fiziko-himičeskie aspekty izučeniâ klasterov, nanostruktur i nanomaterialov

Izvestiya VUZ. Applied Nonlinear Dynamics

Тема и цель исследования. В работе представлены результаты экспериментальных исследований влияния... more Тема и цель исследования. В работе представлены результаты экспериментальных исследований влияния паров воды и интенсивности освещения светодиодом на проводимость тонкой пленки диоксида олова при комнатной температуре. Известно, что использование освещения активных слоев сенсоров позволяет снизить их рабочую температуру, что расширяет область применения сенсоров и мультисенсорных систем на их основе. Целью работы является исследование совместного влияния освещения и воздействия паров воды на проводимость пленок диоксида олова. Методы и материалы. Изучалась газочувствительность сенсоров на основе тонких пленок диоксида олова, сформированных ВЧ магнетронным методом распыления стехиометрической мишени SnO2. Сенсор представлял собой прямоугольную пластину поликора, на которой были сформированы параллельные контакты из нержавеющей стали. Длина контактов 10 мм, зазор между контактами 50 мкм. Толщина активного слоя составляла 0.8 мкм. Газовые пробы, содержащие пары воды, составлялись путем барботирования деионизированной воды потоком синтетического воздуха. Содержание паров воды в газовой пробе определялось соотношением потоков паровоздушной смеси и синтетического воздуха. Результаты. Впервые показано, что при низких уровнях освещения проводимость тонкой пленки диоксида олова при напуске газовых проб увеличивается, а при высоких уровнях освещения-уменьшается. Выполнен численный расчет концентрационных и люксамперных характеристик газочувствительных структур. Обсуждение. Результаты проведенных расчетов по предложенной модели показали, что увеличение или уменьшение проводимости образцов при напуске детектируемого газа определяется положением уровня Ферми в зерне поликристаллического образца до напуска анализируемого газа, которое может контролироваться интенсивностью освещения. Заключение. Полученные результаты могут быть использованы при создании мультисенсорных систем на основе полупроводниковых слоев для детектирования и распознавания примесей газов в окружающей атмосфере.

Technical Physics

The effect of temperature on the vertical growth rate of functional tin dioxide nanostructures fo... more The effect of temperature on the vertical growth rate of functional tin dioxide nanostructures formed by physical vapor deposition from a gas phase is studied. A model is proposed to describe the formation of tin dioxide nanocrystals. This model adequately describes the experimentally detected effect of the deposition zone temperature on the nanocrystal growth rate in the temperature range under study. An analytical relation between the growth rate of a nanowhisker, its geometric parameters, the nanowhisker material, the substrate material, and the technological parameters of its formation is revealed. The crystal growth rate is found to increase with the deposition zone temperature, which can be caused by an activation character of nucleation processes and precursor mass transport along the substrate surface and the lateral nanocrystal surface.

Technical Physics Letters, 2000

... A differential quantum efficiency ηd = 40% was obtained with a 1.9-mm-long Fabry–Perot resona... more ... A differential quantum efficiency ηd = 40% was obtained with a 1.9-mm-long Fabry–Perot resonator. The internal optical losses of the heterostructures are reduced to 2.6–4.2 cm–1. © 2000 MAIK “Nauka/Interperiodica”. Eg D = 1 µm N n N P P+ x Fig. ...

Sensors and Actuators B: Chemical, 2009

Semiconductors, 2000

The effect of oxygen adsorption on the conductivity of a thin homogeneous film of tin dioxide was... more The effect of oxygen adsorption on the conductivity of a thin homogeneous film of tin dioxide was studied. The concentration of free electrons in the film as a function of the partial oxygen pressure in the atmosphere is described using a model formulated within the framework of a flat band approximation. The results of calculations are compared to experimental data.

The experimental current-voltage (I-U) curves of thin-film structures based on tin dioxide (SnO 2... more The experimental current-voltage (I-U) curves of thin-film structures based on tin dioxide (SnO 2) exhibit nonlinearity in the range of strong applied electric fields. The results of I-U measurements are interpreted within the framework of a model that assumes the drift of adsorbed ions over the film surface. The observed phenomenon can be used both for detecting the impurities in air and for recognizing the types of adsorbed species.

Semiconductors, 2006

Symmetric and asymmetric separate-confinement AlGaAs/GaAs heterostructures have been grown by MOC... more Symmetric and asymmetric separate-confinement AlGaAs/GaAs heterostructures have been grown by MOCVD in accordance with the concept of design of high-power semiconductor lasers. High-power laser diodes with a 100-µ m aperture, emitting in the 808-850-nm range, were fabricated from these structures. The internal optical loss in asymmetric separate-confinement heterostructures with broadened waveguide is reduced to 0.5 cm -1 . In the lasers with 1.7-µ m-thick waveguide, the output optical power of 7.5 W in CW mode was achieved owing to reduction of the optical emission density at the cavity mirror to 4 mW/cm 2 .

Russian Journal of Electrochemistry, 2005

Current-voltage curves for sensor structures based on thin tin oxide films are examined in variou... more Current-voltage curves for sensor structures based on thin tin oxide films are examined in various gases. Conditions favoring symmetrical nonlinear curves in the voltage range-30 to 30 V are found.

Abstract book of the 2nd International Scientific Conference "Plants and Microbes: the Future of Biotechnology" PLAMIC2020, 2020

The use of polymer films modified by plasma treatment is proposed as a carrier for immobilizing c... more The use of polymer films modified by plasma treatment is proposed as a carrier for immobilizing cells at create biosensors.

Nano- i Mikrosistemnaya Tehnika, 2017

Solid-state electrochemical cells containing an alkali metal/organic semiconductor direct contact... more Solid-state electrochemical cells containing an alkali metal/organic semiconductor direct contact are studied using a potentiodynamic method. Both ionic and electronic charge transfer processes are possible in heterostructures based on direct contact of alkali metals with p-type semiconductors. The multistage processes proceeding in the systems studied involve chemical reactions and changes in the resistance of both the initial cathode material and the cathodic reduction products.

Instruments and Experimental Techniques, 2009

Technical Physics Letters, 2006

Variation of the current-voltage (I-U) characteristics of thin-film gas sensors based on tin diox... more Variation of the current-voltage (I-U) characteristics of thin-film gas sensors based on tin dioxide (SnO 2) in the presence of various gases has been studied in a range of working temperatures from 200 to 450 ° C. The experimental I-U curves are interpreted assuming that various forms of adsorbed oxygen species are present on the tin dioxide surface and that the adsorbed ions can migrate over the surface with different mobilities. Features of the observed phenomena can be used for selecting working temperatures at which an analysis of the I-U curves can provide a basis for the identification of various species adsorbed on the same sensor.

Technical Physics Letters, 2006

Variation of the conductivity of a thin film of tin dioxide (SnO 2) in response to a stepwise cha... more Variation of the conductivity of a thin film of tin dioxide (SnO 2) in response to a stepwise change in the content of various impurities present in the gas phase has been studied in a broad range of concentrations. The experimental data are interpreted within the framework of the Roginskii-Elovich model of adsorption kinetics. A gas-pressure-independent parameter characterizing the sensor conductivity variation is established. Using the phenomenon under consideration, it is possible to identify adsorbed gas species.

Technical Physics, 1999

ABSTRACT The deposition of tin oxide films by reactive sputtering of a stoichiometric target is i... more ABSTRACT The deposition of tin oxide films by reactive sputtering of a stoichiometric target is investigated. Conditions are determined for the formation of a crystal layer structure and the acquisition of gas sensitivity without subsequent high-temperature annealing.

Russian Journal of Electrochemistry, 2007

Solid-state ionics, based on fast ionic transport in solids and characterized by anomalously larg... more Solid-state ionics, based on fast ionic transport in solids and characterized by anomalously large diffusion coefficients of ions at room temperature and unipolar conductivity (0.05–0.1 S cm−1), assumed in the last few years great importance in the context of creation and subsequent explanation of mechanisms and kinetics of electrode processes during the work of chemical power sources (CPS). It is demonstrated that products of cathodic reactions possess ionic conduction in a solid phase.

Sensors and Actuators B: Chemical, 2006

The nonlinearity of the current-voltage characteristics has been observed in thin films of the ti... more The nonlinearity of the current-voltage characteristics has been observed in thin films of the tin oxide exposed to strong electric fields. The experimental data are discussed assuming the drift-type behavior of the absorbed ions along the surface. The observed phenomena allow application for both air contamination detection and the contamination identification.

Physical and Chemical Aspects of the Study of Clusters, Nanostructures and Nanomaterials, Dec 15, 2017

Рецензирование статей осуществляется на основания Положения об рецензировании статей и материалов... more Рецензирование статей осуществляется на основания Положения об рецензировании статей и материалов для опубликования в Межвузовском сборнике научных трудов «Физико-химические аспекты изучения кластеров, наноструктур и наноматериалов». Официальный сайт издания в сети Интернет: www.physchemaspects.ru Ф50 Физико-химические аспекты изучения кластеров, наноструктур и наноматериалов [Текст]: межвуз. сб. науч. тр. / под общей редакцией

Applied Biochemistry and Microbiology, 2020

It is shown that microbial cells can be immobilized on polymer matrices modified via plasma treat... more It is shown that microbial cells can be immobilized on polymer matrices modified via plasma treatment. On the example of microbial cells Azospirillum brasilense Sp 7, A. lipoferum Sp59b, and Escherichia coli XL-1, it was found that the immobilization efficiency of biological objects depends on the film processing time in plasma. Treatment of a polystyrene film in a high-frequency discharge plasma allowed a significant increase in the lifetime of microbial cells immobilized on its surface. It was shown that the optimal time for film processing in plasma was 30 s, the time to immobilize microbial cells was ~ 20 min, and bacteria remained viable for up to 6 months after immobilization. The use of matrices modified with plasma treatment as a carrier for immobilized the microbial cells to production biosensors is proposed.

Physical and chemical aspects of the study of clusters, nanostructures and nanomaterials

Рецензирование статей осуществляется на основании Положения о рецензировании статей и материалов ... more Рецензирование статей осуществляется на основании Положения о рецензировании статей и материалов для опубликования в Межвузовском сборнике научных трудов «Физико-химические аспекты изучения кластеров, наноструктур и наноматериалов». Официальный сайт издания в сети Интернет: https://www.physchemaspects.ru Ф50 Физико-химические аспекты изучения кластеров, наноструктур и наноматериалов [Текст].  Тверь: Твер. гос. ун-т, 2019.  Вып. 11.  680 с. Зарегистрирован Федеральной службой по надзору в сфере связи, информационных технологий и массовых коммуникаций, свидетельство о регистрации СМИ ПИ № ФС 7747789 от 13.12.2011. Издание составлено из оригинальных статей, кратких сообщений и обзоров теоретического и экспериментального характера, отражающих результаты исследований в области изучения физико-химических процессов с участием кластеров, наноструктур и наноматериалов физики, включая межфазные явления и нанотермодинамику. Сборник предназначен для научных и инженерно-технических работников, преподавателей ВУЗов, студентов и аспирантов. Издание подготовлено на кафедре общей физики Тверского государственного университета. Переводное название: Physical and chemical aspects of the study of clusters, nanostructures and nanomaterials Транслитерация названия: Fiziko-himičeskie aspekty izučeniâ klasterov, nanostruktur i nanomaterialov

Izvestiya VUZ. Applied Nonlinear Dynamics

Тема и цель исследования. В работе представлены результаты экспериментальных исследований влияния... more Тема и цель исследования. В работе представлены результаты экспериментальных исследований влияния паров воды и интенсивности освещения светодиодом на проводимость тонкой пленки диоксида олова при комнатной температуре. Известно, что использование освещения активных слоев сенсоров позволяет снизить их рабочую температуру, что расширяет область применения сенсоров и мультисенсорных систем на их основе. Целью работы является исследование совместного влияния освещения и воздействия паров воды на проводимость пленок диоксида олова. Методы и материалы. Изучалась газочувствительность сенсоров на основе тонких пленок диоксида олова, сформированных ВЧ магнетронным методом распыления стехиометрической мишени SnO2. Сенсор представлял собой прямоугольную пластину поликора, на которой были сформированы параллельные контакты из нержавеющей стали. Длина контактов 10 мм, зазор между контактами 50 мкм. Толщина активного слоя составляла 0.8 мкм. Газовые пробы, содержащие пары воды, составлялись путем барботирования деионизированной воды потоком синтетического воздуха. Содержание паров воды в газовой пробе определялось соотношением потоков паровоздушной смеси и синтетического воздуха. Результаты. Впервые показано, что при низких уровнях освещения проводимость тонкой пленки диоксида олова при напуске газовых проб увеличивается, а при высоких уровнях освещения-уменьшается. Выполнен численный расчет концентрационных и люксамперных характеристик газочувствительных структур. Обсуждение. Результаты проведенных расчетов по предложенной модели показали, что увеличение или уменьшение проводимости образцов при напуске детектируемого газа определяется положением уровня Ферми в зерне поликристаллического образца до напуска анализируемого газа, которое может контролироваться интенсивностью освещения. Заключение. Полученные результаты могут быть использованы при создании мультисенсорных систем на основе полупроводниковых слоев для детектирования и распознавания примесей газов в окружающей атмосфере.

Technical Physics

The effect of temperature on the vertical growth rate of functional tin dioxide nanostructures fo... more The effect of temperature on the vertical growth rate of functional tin dioxide nanostructures formed by physical vapor deposition from a gas phase is studied. A model is proposed to describe the formation of tin dioxide nanocrystals. This model adequately describes the experimentally detected effect of the deposition zone temperature on the nanocrystal growth rate in the temperature range under study. An analytical relation between the growth rate of a nanowhisker, its geometric parameters, the nanowhisker material, the substrate material, and the technological parameters of its formation is revealed. The crystal growth rate is found to increase with the deposition zone temperature, which can be caused by an activation character of nucleation processes and precursor mass transport along the substrate surface and the lateral nanocrystal surface.

Technical Physics Letters, 2000

... A differential quantum efficiency ηd = 40% was obtained with a 1.9-mm-long Fabry–Perot resona... more ... A differential quantum efficiency ηd = 40% was obtained with a 1.9-mm-long Fabry–Perot resonator. The internal optical losses of the heterostructures are reduced to 2.6–4.2 cm–1. © 2000 MAIK “Nauka/Interperiodica”. Eg D = 1 µm N n N P P+ x Fig. ...

Sensors and Actuators B: Chemical, 2009

Semiconductors, 2000

The effect of oxygen adsorption on the conductivity of a thin homogeneous film of tin dioxide was... more The effect of oxygen adsorption on the conductivity of a thin homogeneous film of tin dioxide was studied. The concentration of free electrons in the film as a function of the partial oxygen pressure in the atmosphere is described using a model formulated within the framework of a flat band approximation. The results of calculations are compared to experimental data.

The experimental current-voltage (I-U) curves of thin-film structures based on tin dioxide (SnO 2... more The experimental current-voltage (I-U) curves of thin-film structures based on tin dioxide (SnO 2) exhibit nonlinearity in the range of strong applied electric fields. The results of I-U measurements are interpreted within the framework of a model that assumes the drift of adsorbed ions over the film surface. The observed phenomenon can be used both for detecting the impurities in air and for recognizing the types of adsorbed species.

Semiconductors, 2006

Symmetric and asymmetric separate-confinement AlGaAs/GaAs heterostructures have been grown by MOC... more Symmetric and asymmetric separate-confinement AlGaAs/GaAs heterostructures have been grown by MOCVD in accordance with the concept of design of high-power semiconductor lasers. High-power laser diodes with a 100-µ m aperture, emitting in the 808-850-nm range, were fabricated from these structures. The internal optical loss in asymmetric separate-confinement heterostructures with broadened waveguide is reduced to 0.5 cm -1 . In the lasers with 1.7-µ m-thick waveguide, the output optical power of 7.5 W in CW mode was achieved owing to reduction of the optical emission density at the cavity mirror to 4 mW/cm 2 .