Surface Morphology-Dependent Sensitivity of Thin-Film-Structured Indium Oxide-Based NO2 Gas Sensors

Jian, Li Yi; Lee, Hsin Ying; Lee, Ching-Ting

doi:10.1007/s11664-019-06945-w

Cited by 19 publications

(9 citation statements)

References 27 publications

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“…Further, the enhanced roughness may also provide more adsorption sites to the target gas on the ZnO nanorod surface. 29 , 30 The enhanced view of ZnO nanorods in the 5 μm × 5 μm AFM surface image (left panel) suggests the surface variation for these nanorods, which should be useful for additional adsorption sites.…”

Section: Resultsmentioning

confidence: 99%

“…It is also expected that the enhanced surface roughness of ZnO NRs may provide a dynamic carrier path, which is used in lowering its free energy for ZnO nanorods. Further, the enhanced roughness may also provide more adsorption sites to the target gas on the ZnO nanorod surface. , The enhanced view of ZnO nanorods in the 5 μm × 5 μm AFM surface image (left panel) suggests the surface variation for these nanorods, which should be useful for additional adsorption sites.…”

Section: Resultsmentioning

confidence: 99%

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Low-Temperature Highly Robust Hydrogen Sensor Using Pristine ZnO Nanorods with Enhanced Response and Selectivity

et al. 2022

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We report the hydrogen-sensing response on low-cost-solution-derived ZnO nanorods (NRs) on a glass substrate, integrated with aluminum as interdigitated electrodes (IDEs). The hydrothermally grown ZnO NRs on ZnO seed-layer-glass substrates are vertically aligned and highly textured along the c -axis (002 plane) with texture coefficient ∼2.3. An optimal hydrogen-sensing response of about 21.46% is observed for 150 ppm at 150 °C, which is higher than the responses at 100 and 50 °C, which are ∼12.98 and ∼10.36%, respectively. This can be attributed to the large surface area of ∼14.51 m 2 /g and pore volume of ∼0.013 cm 3 /g, associated with NRs and related defects, especially oxygen vacancies in pristine ZnO nanorods. The selective nature is investigated with different oxidizing and reducing gases like NO 2 , CO, H 2 S, and NH 3 , showing relatively much lower ∼4.28, 3.42, 6.43, and 3.51% responses, respectively, at 50 °C for 50 ppm gas concentration. The impedance measurements also substantiate the same as the observed surface resistance is initially more than bulk, which reduces after introducing the hydrogen gas during sensing measurements. The humidity does not show any significant change in the hydrogen response, which is ∼20.5 ± 1.5% for a large humidity range (from 10 to 65%). More interestingly, the devices are robust against sensing response, showing no significant change after 10 months or even more.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Low-Temperature Highly Robust Hydrogen Sensor Using Pristine ZnO Nanorods with Enhanced Response and Selectivity

et al. 2022

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“…Among the different methods employed for depositing gas sensing MOX thin films, magnetron sputtering [ 11 ] is a reliable and environmentally clean technique. It allows for manufacturing sensing layers with tailored morphologic characteristics, such as grain size, porosity and surface roughness, by opportunely tuning deposition parameters as oxygen (O 2 ) flow ratio, power and working pressure, deposition time and substrate bias voltage [ 11 , 12 , 13 ].…”

Section: Introductionmentioning

confidence: 99%

“…Limiting the scope to NO 2 sensors based on thin films, those prepared exploiting In 2 O 3 show very good performances, as they exhibit a high sensitivity to oxidizing gases such as NO x , even at low working temperatures, and particularly to NO 2 [ 12 , 26 , 27 , 28 , 29 ].…”

Section: Introductionmentioning

confidence: 99%

Characterization of the Response of Magnetron Sputtered In2O3−x Sensors to NO2

Panzardi

Calisi

Enea

et al. 2023

Sensors

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The response of resistive In2O3−x sensing devices was investigated as a function of the NO2 concentration in different operative conditions. Sensing layers are 150 nm thick films manufactured by oxygen-free room temperature magnetron sputtering deposition. This technique allows for a facile and fast manufacturing process, at same time providing advantages in terms of gas sensing performances. The oxygen deficiency during growth provides high densities of oxygen vacancies, both on the surface, where they are favoring NO2 absorption reactions, and in the bulk, where they act as donors. This n-type doping allows for conveniently lowering the thin film resistivity, thus avoiding the sophisticated electronic readout required in the case of very high resistance sensing layers. The semiconductor layer was characterized in terms of morphology, composition and electronic properties. The sensor baseline resistance is in the order of kilohms and exhibits remarkable performances with respect to gas sensitivity. The sensor response to NO2 was studied experimentally both in oxygen-rich and oxygen-free atmospheres for different NO2 concentrations and working temperatures. Experimental tests revealed a response of 32%/ppm at 10 ppm NO2 and response times of approximately 2 min at an optimal working temperature of 200 °C. The obtained performance is in line with the requirements of a realistic application scenario, such as in plant condition monitoring.

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“…In recent years, n-type semiconducting metal oxides, for instance, tin oxide (SnO 2 ), zinc oxide (ZnO), indium oxide (In 2 O 3 ), copper oxide (CuO), titanium oxide (TiO 2 ), and tungsten oxide (WO 3 ), have occupied a pivotal place in the field of gas sensing because of low cost, high sensitivity, simplicity, and easy integration in electronics . Among them, tungsten oxide (WO 3 ) with a wide band gap of 2.6–2.8 eV is attracting more and more attention because of structural diversity, facile preparation, outstanding stability under extreme circumstances, and prominent gas sensing for NO 2 and volatile organic compounds. ,,, Hence, WO 3 is a very prospective n-type semiconductor material for the detection of NO 2 .…”

Section: Introductionmentioning

confidence: 99%

Bilayer Polyaniline–WO₃ Thin-Film Sensors Sensitive to NO₂

Zhao²,

Xiong

2020

ACS Omega

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In this work, a novel bilayer polyaniline–WO3 (PANI–WO3) thin film on the fluorine-doped tin oxide (FTO) glass substrate was prepared by hydrothermal synthesis and in situ chemical oxidative polymerization methods. Until now, no one has ever made attempts to use the PANI–WO3 composite on the FTO glass substrate to detect NO2 gas. The composite showed excellent sensing performance for NO2 detection at an operation temperature of 50 °C and a detection limit of 2 ppm. With regard to the PANI–WO3 hybrid, the response value for NO2 at 30 ppm is 60.19 and is three times higher than that for pure WO3 at 50 °C. Besides, the PANI–WO3 hybrid had excellent stability. The improvement of gas sensing was assigned to the creation of p–n heterojunctions between p-type PANI and n-type WO3, larger specific surface, increase of oxygen vacancies, and a wide conduction channel provided by PANI.

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Surface Morphology-Dependent Sensitivity of Thin-Film-Structured Indium Oxide-Based NO2 Gas Sensors

Cited by 19 publications

References 27 publications

Low-Temperature Highly Robust Hydrogen Sensor Using Pristine ZnO Nanorods with Enhanced Response and Selectivity

Low-Temperature Highly Robust Hydrogen Sensor Using Pristine ZnO Nanorods with Enhanced Response and Selectivity

Characterization of the Response of Magnetron Sputtered In2O3−x Sensors to NO2

Bilayer Polyaniline–WO₃ Thin-Film Sensors Sensitive to NO₂

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Surface Morphology-Dependent Sensitivity of Thin-Film-Structured Indium Oxide-Based NO2 Gas Sensors

Cited by 19 publications

References 27 publications

Low-Temperature Highly Robust Hydrogen Sensor Using Pristine ZnO Nanorods with Enhanced Response and Selectivity

Low-Temperature Highly Robust Hydrogen Sensor Using Pristine ZnO Nanorods with Enhanced Response and Selectivity

Characterization of the Response of Magnetron Sputtered In2O3−x Sensors to NO2

Bilayer Polyaniline–WO3 Thin-Film Sensors Sensitive to NO2

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Bilayer Polyaniline–WO₃ Thin-Film Sensors Sensitive to NO₂