scholarly journals Inhomogeneous Oxygen Vacancy Distribution in Semiconductor Gas Sensors: Formation, Migration and Determination on Gas Sensing Characteristics

Sensors ◽  
2017 ◽  
Vol 17 (8) ◽  
pp. 1852 ◽  
Author(s):  
Jianqiao Liu ◽  
Yinglin Gao ◽  
Xu Wu ◽  
Guohua Jin ◽  
Zhaoxia Zhai ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Gas Sensors ◽  
Gas Sensing ◽  
Vacancy Distribution ◽  
Semiconductor Gas Sensors ◽  
Sensing Characteristics

scholarly journals Influence of Oxygen Vacancy Behaviors in Cooling Process on Semiconductor Gas Sensors: A Numerical Analysis

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3929 ◽  
Author(s):  
Jianqiao Liu ◽  
Wanqiu Wang ◽  
Zhaoxia Zhai ◽  
Guohua Jin ◽  
Yuzhen Chen ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Oxygen Vacancy ◽  
Diffusion Equation ◽  
Gas Sensors ◽  
Gas Sensing ◽  
Cooling Process ◽  
Proposed Model ◽  
Vacancy Model ◽  
Vacancy Distribution ◽  
Semiconductor Gas Sensors

The influence of oxygen vacancy behaviors during a cooling process in semiconductor gas sensors is discussed by the numerical analysis method based on the gradient-distributed oxygen vacancy model. A diffusion equation is established to describe the behaviors of oxygen vacancies, which follows the effects of diffusion and exclusion in the cooling process. Numerical analysis is introduced to find the accurate solutions of the diffusion equation. The solutions illustrate the oxygen vacancy distribution profiles, which are dependent on the cooling rate as well as the temperature interval of the cooling process. The gas-sensing characteristics of reduced resistance and response are calculated. Both of them, together with oxygen vacancy distribution, show the grain size effects and the re-annealing effect. It is found that the properties of gas sensors can be controlled or adjusted by the designed cooling process. The proposed model provides a possibility for sensor characteristics simulations, which may be beneficial for the design of gas sensors. A quantitative interpretation on the gas-sensing mechanism of semiconductors has been contributed.

Time-dependent oxygen vacancy distribution and gas sensing characteristics of tin oxide gas sensitive thin films

2010 ◽  
Vol 150 (1) ◽  
pp. 330-338 ◽  
Author(s):  
Jianqiao Liu ◽  
Shuping Gong ◽  
Qiuyun Fu ◽  
Yi Wang ◽  
Lin Quan ◽  
...  
Keyword(s):  
Thin Films ◽  
Oxygen Vacancy ◽  
Tin Oxide ◽  
Gas Sensing ◽  
Time Dependent ◽  
Vacancy Distribution ◽  
Sensing Characteristics

Pure and Pr-doped Ce4W9O33 with superior hydroxyl scavenging ability: Humidity-independent oxide chemiresistors

2021 ◽  
Author(s):  
Jun-Sik Kim ◽  
Ki Beom Kim ◽  
Huayao Li ◽  
Chan Woong Na ◽  
Kyeorei Lim ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Oxide Semiconductor ◽  
Semiconductor Gas Sensors ◽  
First Time ◽  
Sensing Characteristics ◽  
Standing Problem

Water poisoning has been a long-standing problem in oxide semiconductor gas sensors. Herein, for the first time, we report that pure and Pr-doped Ce4W9O33 provide humidity-independent gas sensing characteristics. The...

Nanocrystalline Materials as Potential Gas Sensing Elements

1997 ◽  
Vol 501 ◽  
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.

Gas Sensing Characteristics of ZnO-doped SnO2 Sensors for Simulants of the Chemical Agents

2005 ◽  
Vol 486-487 ◽  
pp. 9-12 ◽  
Author(s):  
Kwang-Hyun Yun ◽  
Ky-Youl Yun ◽  
Geon-Young Cha ◽  
Bong Ho Lee ◽  
Jae Chang Kim ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Zinc Acetate Dihydrate ◽  
Chemical Agent ◽  
X Ray Diffraction ◽  
Tin Chloride ◽  
Chemical Agents ◽  
Phase Development ◽  
Semiconductor Gas Sensors ◽  
Sensing Characteristics ◽  
Glycol Methyl Ether

After the 9∙11 terrorism and America-Iraq war, apprehension of mass destruction weapons such as bio-chemical agents calls for much more sensitive sensors which can detect toxic gases. In this study, semiconductor gas sensors based on tin oxide were examined to detect chemical agent simulants: dimethyl-methyl-phosponate (DMMP), di(propylene glycol) methyl ether (DPGME), acetonitrile, and dichloromethane. DMMP((CH3O)3), DPGME(C7H16O3), acetonitrile(CH3CN), and dichloromethane(CH2Cl2) gases are the simulants of nerve agent-sarin, vesicant agent-HN(N(CH2CH2Cl)3), blood agent-AC(HCN), and choking agent-CG(COCl2) gases, repectively. The SnO2 powder was prepared by a coprecipitation method from the mixture of tin chloride and zinc acetate dihydrate. Zinc oxide was doped into SnO2 from 1 wt% to 4 wt% to improve its reliability and sensitivity. To fabricate a thick film, powders were made into paste with organic binder of ethyl cellulose and screen-printed on the alumina substrate. The phase development and morphology of ZnO-doped SnO2 film were investigated by XRD (X-ray diffraction analysis), BET (surface and pore size analyzer), and SEM (scanning electron microscope). The gas sensing characteristics for target gases were examined with a flow-type measurement system. The concentrations of simulants were controlled from 500 ppb to 1500 ppb, and working temperatures were regulated from 250 to 400 .

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

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.

scholarly journals Fabrication at wafer level of miniaturized gas sensors based on SnO2 nanorods deposited by PECVD and gas sensing characteristics

2011 ◽  
Vol 154 (2) ◽  
pp. 283-287 ◽  
Author(s):  
A. Forleo ◽  
L. Francioso ◽  
S. Capone ◽  
F. Casino ◽  
P. Siciliano ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Wafer Level ◽  
Sno2 Nanorods ◽  
Sensing Characteristics
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