Vitreous Chalcogenide Semiconductors for Gas Sensing Application

2004 ◽  
Vol 828 ◽  
Author(s):  
Serghei V. Dmitriev ◽  
Igor V. Dementiev
Keyword(s):  
Thin Films ◽  
Gas Sensor ◽  
Solid Solutions ◽  
Gas Sensing ◽  
Flexible Substrate ◽  
Gas Sensitivity ◽  
New Class ◽  
Long Time ◽  
Chalcogenide Materials ◽  
Level 2

ABSTRACTReport presents results of research aimed the investigation of possibility to use such chalcogenide materials as vitreous As2S3, As2Se3 and their solid solutions for gas sensors applications. For a long time these materials were well-known as materials mostly used for optical information registration. Developed approach allows to widening the sphere of application of given materials and create new class of gas sensitive devices.Thin film gas sensitive elements on the base of solid solutions of (As2S3)x-(As2Se3)1−x (where x=0; 0.3; 0.5; 0.7 and 1.0) were obtained by means of the thermal evaporation under vacuum conditions 10−5 Torr. Thin films can be deposited on both hard and flexible substrate. Formed films had specific resistance on the level 1010–1014 Ohm.cm (on dependence on composition) at the thickness of 1–2 μm.It was established that CGS thin films possess gas sensitivity S, determined as S=(Ggas-Gait)/Gair, on the level 2–3 relative units for CO and 7–8 for hydrogen at the 100 ppm concentration levels of both gases in atmosphere already at the room temperature that allows to excluding the heater from the gas sensor construction decreasing through that both manufacturing and operational cost.It is concluded that chalcogenide semiconductor materials can be considered as perspective materials for gas sensor application, including space exploration application.

scholarly journals Chemically synthesized PbS Nano particulate thin films for a rapid NO2 gas sensor

2016 ◽  
Vol 34 (1) ◽  
pp. 204-211 ◽  
Author(s):  
Vishal V. Burungale ◽  
Rupesh S. Devan ◽  
Sachin A. Pawar ◽  
Namdev S. Harale ◽  
Vithoba L. Patil ◽  
...  
Keyword(s):  
Thin Films ◽  
Gas Sensor ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
Silar Method ◽  
Layer Adsorption ◽  
Gas Sensing Properties

AbstractRapid NO2 gas sensor has been developed based on PbS nanoparticulate thin films synthesized by Successive Ionic Layer Adsorption and Reaction (SILAR) method at different precursor concentrations. The structural and morphological properties were investigated by means of X-ray diffraction and field emission scanning electron microscope. NO2 gas sensing properties of PbS thin films deposited at different concentrations were tested. PbS film with 0.25 M precursor concentration showed the highest sensitivity. In order to optimize the operating temperature, the sensitivity of the sensor to 50 ppm NO2 gas was measured at different operating temperatures, from 50 to 200 °C. The gas sensitivity increased with an increase in operating temperature and achieved the maximum value at 150 °C, followed by a decrease in sensitivity with further increase of the operating temperature. The sensitivity was about 35 % for 50 ppm NO2 at 150 °C with rapid response time of 6 s. T90 and T10 recovery time was 97 s at this gas concentration.

BaZrO3Thin Films For Humidity Gas Sensor

2007 ◽  
Vol 1010 ◽  
Author(s):  
XiaoXin Chen ◽  
Michael Sorenson ◽  
Clayton Butler ◽  
Loren Rieth ◽  
Mark S. Miller ◽  
...  
Keyword(s):  
Thin Film ◽  
Crystal Structure ◽  
Thin Films ◽  
Electrical Properties ◽  
Gas Sensor ◽  
Ionic Conduction ◽  
Gas Sensing ◽  
Gas Sensitivity ◽  
Structure And Morphology ◽  
Deposited Films

AbstractMicroscale (MEMS) gas sensing devices for power plant and automobile exhaust gas are being developed. Bulk BaZrO3 has been previously found to be sensitive to H2O at high temperatures, but was never studied in a thin film form. This research thrust focuses on undoped BaZrO3 and doped BaZrO3 with Y.Thin films were deposited on oxidized n-type silicon substrates at room temperature from ceramic targets with an Ar sputtering ambient. Various deposition pressures and deposition powers were used for the initial investigation. The structural and electrical properties of the deposited films were characterized to investigate their relationships to the deposition process parameters. X-ray diffraction (XRD) was used to measure the crystal structure of the deposited films, and in particular was used to determine if any crystallographic texture is present in the films. XRD results indicate the as-deposited films are amorphous before annealing. Films sputtered with and without oxygen in the ambient were compared. The crystal structure and morphology of BaZrO3 and BaZrO3 doped with Y after annealing were also determined. The materials changed from amorphous to crystalline after annealing at temperatures of 800 °C and 1000 °C for 3 hours in forming gas (2% H2 balanced with Ar gas) and oxygen. Temperature was found to dominate over deposition conditions in determining the final film structure. Atomic force microscopy was used to examine the morphology of the thin films. Gas sensor test structures using a Pt thin film metallization for interdigitated electrode structures were fabricated for gas sensing measurements. The experiments with the completed test structures measured the materials¡¦ resistivity as a function of temperature and gas concentration. Both materials decrease in resistance with increasing temperature, which is consistent with ionic conduction. Some experiments tested the gas sensitivity and selectivity of the films to the target gas H2O vapor (humidity) and possible cross sensitive gases H2 and CO2. Both materials need further development to evaluate their suitability for thin film sensors. First, the films were found to be highly resistive, making characterization of the electrical properties very difficult. Second, O2 ambient annealing gas will be applied to compare the crystal structure and morphology of both films with an Ar ambient annealing process.

Metal-oxide based ammonia gas sensors: A review

2020 ◽  
Vol 10 ◽  
Author(s):  
Priya Gupta ◽  
Savita Maurya ◽  
Narendra Kumar Pandey ◽  
Vernica Verma
Keyword(s):  
Metal Oxide ◽  
Metal Oxides ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Review Paper ◽  
Gas Sensing ◽  
Gas Sensitivity ◽  
Ammonia Gas ◽  
Ammonia Sensing ◽  
Ammonia Gas Sensors

: This review paper encompasses a study of metal-oxide and their composite based gas sensors used for the detection of ammonia (NH3) gas. Metal-oxide has come into view as an encouraging choice in the gas sensor industry. This review paper focuses on the ammonia sensing principle of the metal oxides. It also includes various approaches adopted for increasing the gas sensitivity of metal-oxide sensors. Increasing the sensitivity of the ammonia gas sensor includes size effects and doping by metal or other metal oxides which will change the microstructure and morphology of the metal oxides. Different parameters that affect the performances like sensitivity, stability, and selectivity of gas sensors are discussed in this paper. Performances of the most operated metal oxides with strengths and limitations in ammonia gas sensing application are reviewed. The challenges for the development of high sensitive and selective ammonia gas sensor are also discussed.

A facile method for preparation of porous nitrogen-doped Ti Ti3C2Tx MXene for highly responsive acetone detection at high temperature

2021 ◽  
pp. 2151043
Author(s):  
Zijing Wang ◽  
Fen Wang ◽  
Angga Hermawan ◽  
Jianfeng Zhu ◽  
Shu Yin
Keyword(s):  
Gas Sensor ◽  
Recovery Time ◽  
Gas Sensing ◽  
Three Dimensional ◽  
Gas Sensitivity ◽  
Nitrogen Doped ◽  
Dimensional Network ◽  
Potential Applications ◽  
Response And Recovery ◽  
Acetone Detection

Porous nitrogen-doped Ti3C2T[Formula: see text] MXene (N-TCT) with a three-dimensional network structure is synthesized via a simple sacrifice template method and then utilized as an acetone gas sensor. By introducing nitrogen atoms as heteroatoms into Ti3C2T[Formula: see text] nanosheets, some defects generate around the doped nitrogen atoms, which can greatly improve the surface hydrophilicity and adsorption capacity of Ti3C2T[Formula: see text] Mxene nanosheets. It resulted in the enhanced gas sensitivity, achieving a response value of about 36 ([Formula: see text]/[Formula: see text] × 100%) and excellent recovery time (9s) at 150[Formula: see text]C. Compared with the pure Ti3C2T[Formula: see text]-based gas sensor (381/92s), the response and recovery time are both obviously improved, and the response value increased by 3.5 times. The gas-sensing mechanism of the porous N-TCT is also discussed in detail. Based on the excellent gas sensitivity of porous N-TCT for highly responsive acetone detection at high temperatures, the strategy of nitrogen-doped two-dimensional nanomaterials can be extended to other nanomaterials to realize their potential applications.

Palladium thin films on microfiber filtration paper as flexible substrate and its hydrogen gas sensing mechanism

2019 ◽  
Vol 44 (31) ◽  
pp. 17185-17194 ◽  
Author(s):  
Zahra Shahzamani ◽  
Mehdi Ranjbar ◽  
Elisabetta Comini ◽  
Mehdi Torabi Goodarzi ◽  
Hadi Salamati ◽  
...  
Keyword(s):  
Thin Films ◽  
Gas Sensing ◽  
Flexible Substrate ◽  
Hydrogen Gas ◽  
Sensing Mechanism

scholarly journals Gas-sensing features of nanostructured tellurium thin films

2020 ◽  
Vol 11 ◽  
pp. 1010-1018
Author(s):  
Dumitru Tsiulyanu
Keyword(s):  
Thin Films ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Active Surface ◽  
Active Surface Area ◽  
Gas Sensitivity ◽  
Nanocrystalline And Amorphous ◽  
Recovery Times ◽  
Order Of Magnitude ◽  
Response And Recovery

Nanocrystalline and amorphous nanostructured tellurium (Te) thin films were grown and their gas-sensing properties were investigated at different operating temperatures with respect to scanning electron microscopy and X-ray diffraction analyses. It was shown that both types of films interacted with nitrogen dioxide, which resulted in a decrease of electrical conductivity. The gas sensitivity, as well as the response and recovery times, differed between these two nanostructured films. It is worth mentioning that these properties also depend on the operating temperature and the applied gas concentration on the films. An increase in the operating temperature decreased not only the response and recovery times but also the gas sensitivity of the nanocrystalline films. This shortcoming could be solved by using the amorphous nanostructured Te films which, even at 22 °C, exhibited higher gas sensitivity and shorter response and recovery times by more than one order of magnitude in comparison to the nanocrystalline Te films. These results were interpreted in terms of an increase in disorder (amorphization), leading to an increase in the surface chemical activity of chalcogenides, as well as an increase in the active surface area due to substrate porosity.

scholarly journals Enhancement of SnO2 for gas sensing applications

2021 ◽  
Vol 32 (3) ◽  
pp. 63
Author(s):  
O. S. Mahdi ◽  
Nadheer Jassim Mohammed
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Gas Sensing ◽  
Rf Magnetron Sputtering ◽  
Ethanol Vapor ◽  
Gas Sensitivity ◽  
Sensing Applications ◽  
Sno2 Thin Films ◽  
The Rich ◽  
Reactive Rf Magnetron Sputtering

Thin films of SnO2 were deposited by reactive RF magnetron sputtering. It was shown that the films possess gas sensitivity to ethanol vapor at room temperature. XRD, SEM, and EDX measurements of thin films were investigated. Annealing of SnO2 thin films at 800 °С is polycrystalline and grain size of SnO2 in the range about 12 nm. The growth of SnO2 with annealing to 800 °C leads to the percolation nanorods structure. EDX clearly explains the rich of Sn reached 70% annealing. The conductivity of SnO2 nanorods has been increasing at room temperature for ethanol vapors. 

scholarly journals A Set of Platforms with Combinatorial and High-Throughput Technique for Gas Sensing, from Material to Device and to System

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 606 ◽  
Author(s):  
Zhenghao Mao ◽  
Jianchao Wang ◽  
Youjin Gong ◽  
Heng Yang ◽  
Shunping Zhang
Keyword(s):  
Gas Sensor ◽  
High Throughput ◽  
System Integration ◽  
Sensor Array ◽  
Gas Sensing ◽  
Parallel Synthesis ◽  
Testing Platform ◽  
Long Time ◽  
Sensitivity And Selectivity ◽  
Array Optimization

In a new E-nose development, the sensor array needs to be optimized to have enough sensitivity and selectivity for gas/odor classification in the application. The development process includes the preparation of gas sensitive materials, gas sensor fabrication, array optimization, sensor array package and E-nose system integration, which would take a long time to complete. A set of platforms including a gas sensing film parallel synthesis platform, high-throughput gas sensing unmanned testing platform and a handheld wireless E-nose system were presented in this paper to improve the efficiency of a new E-nose development. Inkjet printing was used to parallel synthesize sensor libraries (400 sensors can be prepared each time). For gas sensor selection and array optimization, a high-throughput unmanned testing platform was designed and fabricated for gas sensing measurements of more than 1000 materials synchronously. The structures of a handheld wireless E-nose system with low power were presented in detail. Using the proposed hardware platforms, a new E-nose development might only take one week.

Characterization and Gas Sensing Properties of Spin Coated WO3 Thin Films

2020 ◽  
Vol 234 (11-12) ◽  
pp. 1819-1834
Author(s):  
Sambhaji S. Shendage ◽  
Vithoba L. Patil ◽  
Sharadrao A. Vanalakar ◽  
Sarita P. Patil ◽  
Jalindar L. Bhosale ◽  
...  
Keyword(s):  
Thin Films ◽  
Monoclinic Phase ◽  
Gas Sensing ◽  
Gas Sensitivity ◽  
Film Sensor ◽  
Glass Substrates ◽  
Thin Film Sensors ◽  
Coating Method ◽  
Ft Raman Spectroscopy ◽  
Ft Raman

AbstractThe WO3 thin films have been synthesized on to the glass substrates by a simple and easy spin coating method at different deposition cycles and their sensor responses towards various concentrations of NO2 gas were investigated. The WO3 films were spin coated at a spinning rate of 2500–3000 rpm for 5, 10 and 15 deposition cycles, respectively. Then the films were annealed at 400 °C for 1 h in a furnace. The structural, morphological, optical and electrical properties of WO3 films were studied by different characterization techniques such as X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), FT-RAMAN Spectroscopy and electrical resistivity measurements by laboratory made two probe method respectively. It reveals a spherical grain – like morphology with a pure monoclinic phase of WO3. The FT-RAMAN spectra also confirm the pure monoclinic phase of WO3. The WO3-10 film sensor exhibits maximum gas sensitivity 21.93 and 102.4% to 5 and 100 ppm NO2 at 200 °C, respectively. The WO3-10 thin film sensors is highly sensitive and selective to NO2 over other gases.

Synthesize of Mesoporous ZnO Thin Films and Gas Sensing Property

2014 ◽  
Vol 960-961 ◽  
pp. 157-160
Author(s):  
Min Hee Hong ◽  
Yong June Choi ◽  
Tae Won Lee ◽  
Hee Yoon Chung ◽  
Hyung Ho Park
Keyword(s):  
Thin Films ◽  
Gas Sensing ◽  
Condensation Reaction ◽  
Sol Gel ◽  
Zno Thin Films ◽  
Gas Sensitivity ◽  
Complex Agent ◽  
Sol Gel Process ◽  
Sensor Properties ◽  
Mesoporous Zno

In this work, ordered mesoporous ZnO thin films was synthesized and gas sensor properties were introduced. Mesoporous ZnO thin films were successfully formed by sol-gel process. In ZnO structure, complex agent (MEA) was used for the hydration and condensation reaction. According to the change of MEA concentration, porosity and pore arrangement, specific surface area could be changed. As complex agent concentration decreased, pore ordering was increased and gas sensitivity has the high value (8.01).

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