RECOGNITION OF GAS-AIR MIXTURES BY A SINGLE GAS SENSOR BASED ON TIN DIOXIDE NANOWHISKERS

Нитевидные нанокристаллы диоксида олова были выращены методом физического осаждения из паровой фазы и перенесены на контактную систему методом замороженной капли. Полученные сенсоры обладают газочувствительностью, воздействие паров газов-восстановителей приводит к увеличению их проводимости. Показано, что существует долговременный дрейф проводимости сенсора при воздействии пробы. Исследована концентрационная зависимость чувствительности сенсора к парам этанола, ацетона и пропанол-2 при температуре 300 °С. На основе анализа концентрационных зависимостей проводимости рассчитаны энергии десорбции частиц, а также положения донорных уровней, индуцированных при адсорбции газов-восстановителей, относительно акцепторного уровня кислорода. Показано, что рассчитанные параметры имеют существенно меньший по сравнению с проводимостью временной дрейф. Использование указанных параметров позволяет распознавать газовоздушные смеси, т.е. однозначно отнести одну из трех исследованных проб к её классу. Tin dioxide nanowhiskers were grown by physical vapor deposition and transferred to the contact system by the frozen drop method. The sensors demonstrate gas-sensitivity. Exposing sensors to the atmosphere contained vapors of reducing-gases leads to an increasing of their conductivity. A long-term drift of the sensor conductivity during reducing-gas exposition was shown. A sensitivity response vs concentration for ethanol, acetone, and propanol-2 vapors at temperature 300 °C was investigated. Desorption energies of the particles and the positions of the donor levels induced by adsorption of reducing gases particles were calculated by analysis of the conductivity vs concentration dependence. The calculated parameters had a significantly smaller time drift in comparison with the conductivity. Using of these parameters makes possible to recognize gas-air mixtures: classify the each of three studied samples to one of classes.

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DESINGN OF GAS SENSOR BASED ON TIN OXIDE NANOWHISKERS

Physical and Chemical Aspects of the Study of Clusters Nanostructures and Nanomaterials ◽

10.26456/pcascnn/2020.12.731 ◽

2020 ◽

pp. 731-737

Author(s):

Дмитрий Александрович Тимошенко ◽

Илья Владимирович Синёв ◽

Вячеслав Владимирович Симаков

Keyword(s):

Gas Sensor ◽

Tin Oxide ◽

Vapor Deposition ◽

Tin Dioxide ◽

Average Diameter ◽

Acetone Vapor ◽

Partial Pressure Of Oxygen ◽

Technological Parameters ◽

Gas Sensitivity ◽

Deposition Zone

Методом осаждения из паровой фазы были выращены нитевидные нанокристаллы диоксида олова. Исследовано влияние технологических параметров синтеза на морфологию выращенных наноструктур. Показано, что увеличение парциального давления кислорода в диапазоне от 0,06 мбар до 9,3 мбар и температуры зоны осаждения в диапазоне от 940 °С до 995 °С приводит к увеличению диаметра формируемых нитевидных нанокристаллов. В экспериментах установлено, что средний диаметр нитевидных нанокристаллов варьировался от 80 нм до 250 нм. На основе полученных нанокристаллов был сформирован активный слой газового сенсора, чувствительный к парам ацетона в воздухе. Величина газочувствительности и характерные времена отклика полученного сенсора достаточны для практического применения в газоанализаторах и системах распознавания газовых смесей и запахов. Tin dioxide nanowhiskers were grown by the vapor deposition. The effect of technological parameters on the morphology of the grown nanostructures was investigated. It is shown that an increase in the partial pressure of oxygen in the range from 0,06 mbar to 9,3 mbar and the temperature of the deposition zone in the range from 940 °C to 995 °C leads to an increase in the diameter of the formed nanocrystals. Experimentally it was shown that the average diameter of nanowhiskers varied from 80 nm to 250 nm. A gas sensor was formed with an active layer, based on the nanocrystals, sensitive to acetone vapor. The value of the gas sensitivity and the characteristic times of the sensor are sufficient for practical use in gas analyzers and systems for recognizing gas mixtures and odors.

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The Influence of Catalysts on the Gas Sensitivity of a Gas Sensor Based on SnO2 Films + 1 % at. Si

Nano Hybrids and Composites ◽

10.4028/www.scientific.net/nhc.28.161 ◽

2020 ◽

Vol 28 ◽

pp. 161-169

Author(s):

Tatyana Aleksandrovna Perepechina ◽

Stanislav Ivanovich Rembeza ◽

Tamara Vital'evna Svistova ◽

Еkaterina Stanislavovna Rembeza ◽

Vadim Aleksandrovich Buslov

Keyword(s):

Surface Modification ◽

Film Thickness ◽

Gas Sensor ◽

Tin Dioxide ◽

Operating Temperature ◽

Sensitive Layer ◽

Gas Sensitivity ◽

Microelectronic Technology

The paper is devoted to the study of the influence of surface modification by catalysts on the gas sensitivity of a gas sensor. The sample for the study is a gas sensor crystal with dimensions of 1 × 1 mm2, manufactured using microelectronic technology. Its design is represented by a film heater, two sensitive elements (SE) based on tin dioxide with the addition of 1 % at. Si (film thickness = 250 nm, the size of the SE area is 200 x 320 μm2) and contacts for the sensitive layer in the form of an interdigital platinum structure with a distance between contacts of 10 μm. It is established that doping increases the gas sensitivity and lowers the operating temperature.

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Stabilizer-Free Metal Nanoparticles and Metal-Metal Oxide Nanocomposites with Long-Term Stability Prepared by Physical Vapor Deposition into Ionic Liquids

Angewandte Chemie International Edition ◽

10.1002/anie.200901562 ◽

2010 ◽

Vol 49 (13) ◽

pp. 2431-2435 ◽

Cited By ~ 90

Author(s):

Kai Richter ◽

Alexander Birkner ◽

Anja-Verena Mudring

Keyword(s):

Ionic Liquids ◽

Metal Oxide ◽

Metal Nanoparticles ◽

Vapor Deposition ◽

Physical Vapor Deposition ◽

Term Stability ◽

Long Term Stability ◽

Metal Metal ◽

Free Metal

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Effect of temperature on the growth rate of tin dioxide whiskers formed by physical vapor deposition

Technical Physics ◽

10.1134/s1063784216040216 ◽

2016 ◽

Vol 61 (4) ◽

pp. 574-578 ◽

Cited By ~ 2

Author(s):

V. V. Simakov ◽

I. V. Sinev ◽

A. V. Smirnov ◽

A. I. Grebennikov

Keyword(s):

Growth Rate ◽

Vapor Deposition ◽

Physical Vapor Deposition ◽

Tin Dioxide ◽

Effect Of Temperature

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PRINCIPLES OF CREATING A VIRTUAL MULTI-SENSOR SYSTEM FOR RECOGNITION GAS MIXTURES

Physical and Chemical Aspects of the Study of Clusters Nanostructures and Nanomaterials ◽

10.26456/pcascnn/2020.12.827 ◽

2020 ◽

pp. 827-835

Author(s):

Максим Дмитриевич Корабель ◽

Илья Владимирович Синёв ◽

Дмитрий Алексеевич Шикунов ◽

Никита Александрович Клычков ◽

Дмитрий Александрович Тимошенко ◽

...

Keyword(s):

Concentration Dependence ◽

Power Law ◽

Tin Dioxide ◽

Operating Mode ◽

Operating Conditions ◽

Gas Sensitivity ◽

Wide Range ◽

Power Law Exponent ◽

Dioxide Film

В широком диапазоне концентраций газов различной химической природы (аммиака, ацетона, пропанола и этанола) исследовалась концентрационная зависимость газочувствительности сенсора газа на основе наноструктурированной пленки диоксида олова при различных режимах его работы. Экспериментально показано, что концентрационная зависимость газочувствительности носит степенной характер, показатель степени n различен для разных газовых проб, причем величина показателя степенного закона n зависит от режима работы сенсора и химической природы анализируемой пробы. Изученное явление позволяет распознавать газовые пробы, содержащие пары веществ различной химической природы. Вероятность классификации газовых проб аммиака, ацетона, пропанола и этанола методом ближайших соседей составила более 95 %. The concentration dependence of the gas sensitivity of a gas sensor based on a nanostructured tin dioxide film was studied under various operating conditions in a wide range of concentrations of gases of various nature (ammonia, acetone, propanol, and ethanol). It has been experimentally shown that the concentration dependence of the gas sensitivity is power-law, the exponent n is different for different gas samples, and the value of the power-law exponent n depends on the operating mode of the sensor and the chemical nature of the sample being analyzed. The studied phenomenon makes it possible to recognize gas samples containing vapors of different chemical substances. The probability of classification of gas samples of ammonia, acetone, propanol and ethanol by the method of nearest neighbors was more than 95 %.

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TEM characterization of WSix films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171973 ◽

1994 ◽

Vol 52 ◽

pp. 848-849

Author(s):

V. C. Kannan ◽

S. M. Merchant ◽

R. B. Irwin ◽

A. K. Nanda ◽

M. Sundahl ◽

...

Keyword(s):

Integrated Circuits ◽

Vapor Deposition ◽

High Purity ◽

Physical Vapor Deposition ◽

Thermal Treatments ◽

Rapid Thermal Anneal ◽

Tungsten Silicide ◽

Tem Characterization ◽

Metal Silicides

Metal silicides such as WSi2, MoSi2, TiSi2, TaSi2 and CoSi2 have received wide attention in recent years for semiconductor applications in integrated circuits. In this study, we describe the microstructures of WSix films deposited on SiO2 (oxide) and polysilicon (poly) surfaces on Si wafers afterdeposition and rapid thermal anneal (RTA) at several temperatures. The stoichiometry of WSix films was confirmed by Rutherford Backscattering Spectroscopy (RBS). A correlation between the observed microstructure and measured sheet resistance of the films was also obtained.WSix films were deposited by physical vapor deposition (PVD) using magnetron sputteringin a Varian 3180. A high purity tungsten silicide target with a Si:W ratio of 2.85 was used. Films deposited on oxide or poly substrates gave rise to a Si:W ratio of 2.65 as observed by RBS. To simulatethe thermal treatments of subsequent processing procedures, wafers with tungsten silicide films were subjected to RTA (AG Associates Heatpulse 4108) in a N2 ambient for 60 seconds at temperatures ranging from 700° to 1000°C.

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