Tin Dioxide Thin Film with UV-enhanced Acetone Detection in Microwave Frequency Range

In this paper, the UV illumination effect for microwave gas sensors based on the tin dioxide was verified. A UV LED with emission wavelength close to the absorption edge of the SnO2 gas-sensing layer was selected as the UV source. The developed gas sensors were tested under exposure to acetone in the 0–200 ppm range at room temperature. The sensor’s complex reflection coefficient corresponding to target gas concentration was measured with the use of a five-port reflectometer system exhibiting enhanced uncertainty distribution, which allows for the detection of low gas concentration. The UV illumination significantly emphasizes the sensors’ response in terms of both magnitude and phase for low gas concentrations, in contrast to previously reported results, in which only the reflection coefficient’s phase was affected. The highest responses were obtained for modulated UV illumination.

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Study of properties of electrical conductivity of Tin dioxide thin films treated with Xenon impulse radiation used as Gas sensors

Baghdad Science Journal ◽

10.21123/bsj.6.4.693-697 ◽

2009 ◽

Vol 6 (4) ◽

pp. 693-697

Author(s):

Baghdad Science Journal

Keyword(s):

Thin Films ◽

Electrical Conductivity ◽

Short Duration ◽

Gas Sensors ◽

Tin Dioxide ◽

Experimental Result ◽

Gas Sensitivity ◽

Gas Concentration ◽

Similar Character

During of Experimental result of this work , we found that the change of electrical conductivity proprieties of tin dioxide with the change of gas concentration at temperatures 260oC and 360oC after treatment by photons rays have similar character after treatment isothermally. We found that intensive short duration impulse annealing during the fractions of a second leads to crystallization of the films and to the high values of its gas sensitivity.

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Applications of Nanostructured Materials as Gas Sensors

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.201.131 ◽

2013 ◽

Vol 201 ◽

pp. 131-158 ◽

Cited By ~ 2

Author(s):

Ravi Chand Singh ◽

Manmeet Pal Singh ◽

Hardev Singh Virk

Keyword(s):

Metal Oxide ◽

Gas Sensors ◽

Tin Dioxide ◽

Gas Sensing ◽

Dominant Role ◽

Low Cost ◽

Critical Role ◽

Health And Safety ◽

Chemical Route ◽

Metal Oxide Sensors

Gas detection instruments are increasingly needed for industrial health and safety, environmental monitoring, and process control. To meet this demand, considerable research into new sensors is underway, including efforts to enhance the performance of traditional devices, such as resistive metal oxide sensors, through nanoengineering. The resistance of semiconductors is affected by the gaseous ambient. The semiconducting metal oxides based gas sensors exploit this phenomenon. Physical chemistry of solid metal surfaces plays a dominant role in controlling the gas sensing characteristics. Metal oxide sensors have been utilized for several decades for low-cost detection of combustible and toxic gases. Recent advances in nanomaterials provide the opportunity to dramatically increase the response of these materials, as their performance is directly related to exposed surface volume. Proper control of grain size remains a key challenge for high sensor performance. Nanoparticles of SnO2have been synthesized through chemical route at 5, 25 and 50°C. The synthesized particles were sintered at 400, 600 and 800°C and their structural and morphological analysis was carried out using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The reaction temperature is found to be playing a critical role in controlling nanostructure sizes as well as agglomeration. It has been observed that particle synthesized at 5 and 50°C are smaller and less agglomerated as compared to the particles prepared at 25°C. The studies revealed that particle size and agglomeration increases with increase in sintering temperature. Thick films gas sensors were fabricated using synthesized tin dioxide powder and sensing response of all the sensors to ethanol vapors was investigated at different temperatures and concentrations. The investigations revealed that sensing response of SnO2nanoparticles is size dependent and smaller particles display higher sensitivity. Table of Contents

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Nanocrystalline Materials as Potential Gas Sensing Elements

MRS Proceedings ◽

10.1557/proc-501-33 ◽

1997 ◽

Vol 501 ◽

Cited By ~ 3

Author(s):

G. S. V. Coles ◽

G. Williams

Keyword(s):

Gas Sensors ◽

Nanocrystalline Materials ◽

Tin Dioxide ◽

Gas Sensing ◽

Electronics Industry ◽

Laser Evaporation ◽

Foreseeable Future ◽

Specific Context ◽

Semiconductor Gas Sensors ◽

Cost Of Materials

ABSTRACTSensors and Transducers, and in the specific context of this paper gas sensors, are currently amongst the largest growth areas in the modem electronics industry and this seems likely to continue for the foreseeable future. Nanocrystalline materials posses many properties that could make them ideal as potential gas sensing elements with many advantages over their microcrystalline counterparts. Most importantly these include increased surface area coupled with reduced sintering temperatures and times. However, it should also be noted that there are several disadvantages including the comparatively high cost of materials and increased electrical resistance.This paper reviews the operating mechanisms of semiconductor gas sensors and the possible advantages of using nano sized powders to produce gas sensitive devices. Results are presented which have been obtained from several materials produced by laser evaporation including alumina (Al2O3), zirconia (ZrO2), and tin dioxide (SnO2) in contaminated atmospheres incorporating carbon monoxide, hydrogen and methane.

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Embedded Transdermal Alcohol Detection via a Finger Using SnO2 Gas Sensors

Sensors ◽

10.3390/s21206852 ◽

2021 ◽

Vol 21 (20) ◽

pp. 6852

Author(s):

Fatima Ezahra Annanouch ◽

Virginie Martini ◽

Tomas Fiorido ◽

Bruno Lawson ◽

Khalifa Aguir ◽

...

Keyword(s):

Gas Sensors ◽

Tin Dioxide ◽

Gas Sensing ◽

Low Cost ◽

High Sensitivity ◽

Rf Magnetron Sputtering ◽

Alcohol Concentration ◽

Invasive Technique ◽

Clear Correlation ◽

Wide Range

In this paper, we report the fabrication and characterization of a portable transdermal alcohol sensing device via a human finger, using tin dioxide (SnO2) chemoresistive gas sensors. Compared to conventional detectors, this non-invasive technique allowed us the continuous monitoring of alcohol with low cost and simple fabrication process. The sensing layers used in this work were fabricated by using the reactive radio frequency (RF) magnetron sputtering technique. Their structure and morphology were investigated by means of X-ray spectroscopy (XRD) and scanning electron microscopy (SEM), respectively. The results indicated that the annealing time has an important impact on the sensor sensitivity. Before performing the transdermal measurements, the sensors were exposed to a wide range of ethanol concentrations and the results displayed good responses with high sensitivity, stability, and a rapid detection time. Moreover, against high relative humidity (50% and 70%), the sensors remained resistant by showing a slight change in their gas sensing performances. A volunteer (an adult researcher from our volunteer group) drank 50 mL of tequila in order to realize the transdermal alcohol monitoring. Fifteen minutes later, the volunteer’s skin started to evacuate alcohol and the sensor resistance began to decline. Simultaneously, breath alcohol measurements were attained using a DRAGER 6820 certified breathalyzer. The results demonstrated a clear correlation between the alcohol concentration in the blood, breath, and via perspiration, which validated the embedded transdermal alcohol device reported in this work.

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Enhanced Gas Sensing of Tin Dioxide Based Sensor for Indoor Formaldehyde Application

Journal of Nanoelectronics and Optoelectronics ◽

10.1166/jno.2021.2937 ◽

2021 ◽

Vol 16 (2) ◽

pp. 337-342

Author(s):

Gaoqi Zhang ◽

Fan Zhang ◽

Kaifang Wang ◽

Shanyu Liu ◽

Ying Wang ◽

...

Keyword(s):

Gas Sensors ◽

Tin Dioxide ◽

Gas Sensing ◽

Fast Response ◽

Sensing Material ◽

Gas Sensing Properties ◽

Recovery Times ◽

Response And Recovery ◽

Formaldehyde Sensing ◽

Gas Response

Indoor formaldehyde detection is of great important at present. Using efficient solvothermal method, nanosheet-constructed and nanorod-constructed hierarchical tin dioxide (SnO2) microspheres were successfully synthesized in this work and used for the gas sensing material for indoor formaldehyde application. The as-prepared two kinds of SnO2 gas sensing materials were applied to fabricate the gas sensors and formaldehyde gas sensing experiments were carried out. The HCHO gas sensing tests indicate that the gas response of the nanosheet-constructed SnO2 microspheres is about 1.7 times higher than that of the nanorod-constructed SnO2 microspheres. In addition, both of the two SnO2 based gas sensors show almost fast response and recovery time to HCHO gas. For the nanosheet-constructed microspheres, the response value is estimated to be 32.0 at 350 °C to 60 ppm formaldehyde gas, while the response and recovery times are 7 and 5 s, respectively. The simple and efficient preparation method and improved gas sensing properties show that the as-synthesized hierarchical SnO2 microsphere that is constructed by a large amount of nanosheets exhibits significant potential application for the indoor formaldehyde sensing.

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Formation of Highly Porous Gas-sensing Films by In-situ Thermophoretic Deposition of Nanoparticles from Aerosol Phase

MRS Proceedings ◽

10.1557/proc-0915-r07-03 ◽

2006 ◽

Vol 915 ◽

Author(s):

Thorsten Sahm ◽

Weizhi Rong ◽

Nicolae Barsan ◽

Lutz Mädler ◽

Sheldon K. Friedlander ◽

...

Keyword(s):

Gas Sensors ◽

Tin Dioxide ◽

Gas Sensing ◽

High Sensitivity ◽

High Catalytic Activity ◽

Flame Spray ◽

Ceramic Substrates ◽

Pd Doping ◽

Sensor Signals

AbstractGas sensors based on tin dioxide nanoparticles show high sensitivity to reducing and oxidizing gases. Dry aerosol synthesis applying the flame spray pyrolysis was used for manufacture and directly (in-situ) deposit nanoparticles on sensor substrates. For the first time this technique has been used to synthesize a combination of two stacked porous layers for gas sensor fabrication. Compared to state-of-the-art techniques, aerosol technology provides a direct and versatile method to produce homogeneous nanoparticle films. Two different sensing layers were deposited directly on interdigital ceramic substrates. These porous bottom layers consisted either of pure tin dioxide or palladium doped tin dioxide. The top layer was a palladium doped alumina nanoparticle film which served as a chemical filter. The fabricated gas sensors were tested with methane, CO and ethanol. In case of CH4 detection, the pure tin dioxide sensor with the Pd/Al2O3 filter layer showed higher sensor signals and significantly improved analyte selectivity with respect to water vapor compared to single tin dioxide films. At temperatures up to 250°C the Pd-doping of the tin dioxide strongly increased the sensitivity to all gases. At higher temperatures the sensor signal significantly decreased for the Pd/SnO2 sensor with a Pd/Al2O3 filter on top indicating high catalytic activity.

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Spay Pyrolyzed Nanostructured Tin Dioxide Thin Films Doped by Cobalt: Correlation between Structural and Gas Sensing Characteristics

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.377.180 ◽

2013 ◽

Vol 377 ◽

pp. 180-185

Author(s):

Ghenadii Korotcenkov ◽

Iulia Boris ◽

Vladimir Brinzari ◽

Beongki Cho

Keyword(s):

Thin Films ◽

Spray Pyrolysis ◽

Structural Properties ◽

Gas Sensors ◽

Tin Dioxide ◽

Gas Sensing ◽

Co Doping ◽

Low Levels ◽

Sensing Characteristics ◽

Operation Characteristics

Effect of Co-doping on gas sensing, electrophysical and structural properties of the SnO2films deposited by spray pyrolysis has been studied. It is found that the influence of Co-doping on parameters of the SnO2-based gas sensors depends on the concentration of doping additives and could be accompanied by either improvement of sensor parameters at low levels of doping (CCo< 2-4 %) or degradation of the gas sensor operation characteristics while the concentration of additives exceeds 2-4%. An explanation of observed effects is given.

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UV-enhanced NO2 gas sensors based on In2O3/ZnO composite material modified by polypeptides

Nanotechnology ◽

10.1088/1361-6528/ac46b2 ◽

2021 ◽

Author(s):

Zhihua Ying ◽

Teng Zhang ◽

Chao Feng ◽

Fei Wen ◽

Lili Li ◽

...

Keyword(s):

Composite Material ◽

Gas Sensor ◽

Gas Sensors ◽

Active Sites ◽

High Performance ◽

Gas Sensing ◽

Uv Light ◽

Gas Concentration ◽

One Step ◽

Strong Linear Relationship

Abstract This present study reported a high-performance gas sensor, based on In2O3/ZnO composite material modified by polypeptides, with a high sensibility to NO2, where the In2O3/ZnO composite was prepared by a one-step hydrothermal method. A series of results through material characterization technologies showed the addition of polypeptides can effectively change the morphology and size of In2O3/ZnO crystals, and effectively improve the sensing performance of the gas sensors. Due to the single shape and small size, In2O3/ZnO composite modified by polypeptides increased the active sites on the surface. At the same time, the gas sensing properties of four different ratios of polypeptide-modified In2O3/ZnO gas sensors were tested. It was found that the In2O3/ZnO-10 material showed the highest response, excellent selectivity, and good stability at room temperature under UV light. In addition, the response of the In2O3/ZnO-10 gas sensor showed a strong linear relationship with the NO2 gas concentration. When the NO2 gas concentration was 20 ppm, the response time was as quick as 19s, and the recovery time was 57s. Finally, based on the obtained experimental characterization results and energy band structure analysis, a possible gas sensing mechanism is proposed.

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Metal Oxide Thin Films Prepared by Magnetron Sputtering Technology for Volatile Organic Compound Detection in the Microwave Frequency Range

Materials ◽

10.3390/ma12060877 ◽

2019 ◽

Vol 12 (6) ◽

pp. 877 ◽

Cited By ~ 12

Author(s):

Artur Rydosz ◽

Andrzej Brudnik ◽

Kamil Staszek

Keyword(s):

Thin Films ◽

Magnetron Sputtering ◽

Metal Oxide ◽

Gas Sensors ◽

Biomedical Applications ◽

Tin Dioxide ◽

Microwave Frequency ◽

Oxide Thin Films ◽

Metal Oxide Thin Films ◽

Volatile Organic

Metal oxide thin films such as copper oxide, titanium dioxide, and tin dioxide deposited by magnetron sputtering technology were verified as a gas-sensitive layer in microwave-based gas sensors operated at 2.4 GHz. The developed gas sensors were tested at room temperature (23 °C) and 50% relative humidity (RH) under exposure to 0–200 ppm of selected volatile organic compounds (acetone, ethanol, and methanol) that are of high interest in industry and biomedical applications. The highest responses to acetone were obtained for CuO-based gas sensors, to ethanol for SnO2-based gas sensors, while for methanol detection both dioxides, SnO2 and TiO2, exhibited good sensitivity.

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