scholarly journals High-Sensitive Numerical Gas Detection Using LSPR Effect and Fano Resonance in a Slotted MDM Structure

2021 ◽  
Author(s):  
Hai Liu ◽  
Benlei Zhao ◽  
Xu Zhang ◽  
Hancheng Zhang ◽  
Bo Wu ◽  
...  
Keyword(s):  
Fano Resonance ◽  
Gas Sensing ◽  
Field Enhancement ◽  
Fast Response ◽  
Gas Detection ◽  
Localized Surface Plasmon ◽  
Gas Sensitivity ◽  
Combined Use ◽  
Coherent Coupling ◽  
Lspr Effect

AbstractA high-sensitive numerical measurement of methane based on the combined use of the localized surface plasmon resonance (LSPR) and Fano resonance in a slotted metal-dielectric-metal (MDM) periodic structure is numerically investigated. A groove is etched in an original MDM structure to excite the diploe mode at both sides of the groove, and the coherent coupling of two dipole modes is enhanced to realize a fast response, which is beneficial to gas-sensing. The influence of geometric parameters on the reflection spectra and methane sensitivity are analyzed to obtain optimal geometry. Moreover, an etching ring is introduced on the top metal to further raise the coupling area and coupling strength. The Fano resonance is subtly integrated into the optimized structure with asymmetry to achieve greater gas sensitivity. After the introduction of the Fano resonance, the field enhancement caused by the LSPR effect becomes greater and the methane sensitivity can reach up to 8.421 nm/% in numerical calculations, which increases 56.8% more than that of the original one. The combined use of the LSPR and Fano resonance in an optimized MDM structure provides an effective method for high-sensitive gas detection.

scholarly journals Nanostructured ZnO/Ag Film Prepared by Magnetron Sputtering Method for Fast Response of Ammonia Gas Detection

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1899 ◽  
Author(s):  
Yiran Zheng ◽  
Min Li ◽  
Xiaoyan Wen ◽  
Ho-Pui Ho ◽  
Haifei Lu
Keyword(s):  
Magnetron Sputtering ◽  
Thermal Annealing ◽  
Physical Vapor Deposition ◽  
Gas Sensing ◽  
Volume Ratio ◽  
Fast Response ◽  
Gas Detection ◽  
Zno Films ◽  
Zno Film ◽  
Ammonia Gas

Possessing a large surface-to-volume ratio is significant to the sensitive gas detection of semiconductor nanostructures. Here, we propose a fast-response ammonia gas sensor based on porous nanostructured zinc oxide (ZnO) film, which is fabricated through physical vapor deposition and subsequent thermal annealing. In general, an extremely thin silver (Ag) layer (1, 3, 5 nm) and a 100 nm ZnO film are sequentially deposited on the SiO2/Si substrate by a magnetron sputtering method. The porous nanostructure of ZnO film is formed after thermal annealing contributed by the diffusion of Ag among ZnO crystal grains and the expansion of the ZnO film. Different thicknesses of the Ag layer help the formation of different sizes and quantities of hollows uniformly distributed in the ZnO film, which is demonstrated to hold superior gas sensing abilities than the compact ZnO film. The responses of the different porous ZnO films were also investigated in the ammonia concentration range of 10 to 300 ppm. Experimental results demonstrate that the ZnO/Ag(3 nm) sensor possesses a good electrical resistance variation of 85.74% after exposing the sample to 300 ppm ammonia gas for 310 s. Interestingly, a fast response of 61.18% in 60 s for 300 ppm ammonia gas has been achieved from the ZnO/Ag(5 nm) sensor, which costs only 6 s for the response increase to 10%. Therefore, this controllable, porous, nanostructured ZnO film maintaining a sensitive gas response, fabricated by the physical deposition approach, will be of great interest to the gas-sensing community.

Reduced Graphene Oxide Screen Printed Thick Film as NO2 Gas Sensor at Low Temperature

2021 ◽  
Vol 1167 ◽  
pp. 43-55
Author(s):  
Anil Patil ◽  
Umesh Tupe ◽  
Arun V. Patil
Keyword(s):  
Graphene Oxide ◽  
Thick Film ◽  
Reduced Graphene Oxide ◽  
Gas Sensing ◽  
Thick Films ◽  
Research Work ◽  
Fast Response ◽  
Gas Sensitivity ◽  
Reduced Graphene ◽  
Sensitivity And Selectivity

Most of the recent reduced graphene oxide (rGO) based sensors shows gas sensitivity above 50o to 150°C. The present investigation deals with the gas sensing at 50°C temperature. In the present research work, thick film sensors of rGO were developed on glass substrate by using standard screen-printing technique. The silver paste of rGO was used to make electrodes for contact on thick films for the electrical and gas sensing system. The electrical properties of rGO thick films such as resistivity, activation energy and temperature coefficient were studied. The resistivity of rGO thick films was found to be 84.84 Ω/m. The morphological, elemental and structural properties of rGO thick films were analyzed by SEM, EDS and XRD techniques respectively. The crystallite size of rGO thick films was found as 28.42 nm by using Scherer’s formula. The rGO thick films were prepared and exposed to Ethanol, NH3, NO2 and LPG gases to determine sensitivity and selectivity. The sensitivity of NO2 has been found to be maximum among other exposed gases. The maximum sensitivity of NO2 gas was 92.55 % at 50 °C found with fast response (~ 11 sec) and recovery (~ 19 sec) time.

scholarly journals Fast Response Isopropanol Sensing Properties with Sintered BiFeO3 Nanocrystals

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3829 ◽  
Author(s):  
Hongxiang Xu ◽  
Junhua Xu ◽  
Junlin Wei ◽  
Yamei Zhang
Keyword(s):  
Gas Sensing ◽  
Fast Response ◽  
Gas Detection ◽  
Detection Range ◽  
Sensing Properties ◽  
Working Temperature ◽  
Sensing Material ◽  
Gas Sensing Properties ◽  
Response And Recovery ◽  
Optimum Working

BiFeO3 nanocrystals were applied as the sensing material to isopropanol. The isopropanol sensor based on BiFeO3 nanocrystals shows excellent gas-sensing properties at the optimum working temperature of 240 °C. The sensitivity of as-prepared sensor to 100 ppm isopropanol is 31 and its response and recovery time is as fast as 6 and 17 s. The logarithmic curves of the sensitivity and concentration of BiFeO3 sensors are a very good linear in the low detection range of 2–100 ppm. In addition, the gas sensing mechanism is also discussed. The results suggest that the BiFeO3 nanomaterial can be potentially applied in isopropanol gas detection.

scholarly journals Synthesis and H2S Gas Sensing Characteritics of Nanostructured V2O5

2021 ◽  
Vol 31.2 (149) ◽  
pp. 115-118
Keyword(s):  
Gas Sensing ◽  
Fast Response ◽  
Gas Sensitivity ◽  
Orthorhombic Crystal ◽  
Xrd Pattern ◽  
Sem Image ◽  
Low Concentrations ◽  
H2s Gas Sensor ◽  
Response And Recovery ◽  
Material Good

In this study, V2O5 nanomaterials were successfully synthesized by a facile hydrothermal method and tested for application in preparing toxic H2S gas sensor. SEM image shows that the material has the shape of nanoplates with different sizes ranging from 100 to 500 nm. The XRD pattern shows that the material has a single phase of Orthorhombic crystal of V2O5. The results of the gas sensitivity survey show that the material good respond to H2S at low concentrations (2.5-20 ppm) with relatively fast response and recovery time. This study demonstrates the potential of application of V2O5 material in H2S gas sensors.

Tuning the Localized Surface Plasmon Resonance of Al-Al2O3 Nanosphere Towards NIR Region by Gold Coating

2020 ◽  
Vol 12 ◽  
Author(s):  
Jyoti Katyal ◽  
Shivani Gautam
Keyword(s):  
Electric Field ◽  
Field Distribution ◽  
Dielectric Layer ◽  
Electric Field Distribution ◽  
Active Material ◽  
Visible Region ◽  
Field Enhancement ◽  
Localized Surface Plasmon ◽  
Sers Substrate ◽  
Al Nanoparticles

Background: A relatively narrow LSPR peak and a strong inter band transition ranging around 800 nm makes Al strongly plasmonic active material. Usually, Al nanoparticles are preferred for UV-plasmonic as the SPR of small size Al nanoparticles locates in deep UV-UV region of the optical spectrum. This paper focused on tuning the LSPR of Al nanostructure towards infrared region by coating Au layer. The proposed structure has Au as outer layer which prevent the further oxidation of Al nanostructure. Methods: The Finite Difference Time Domain (FDTD) and Plasmon Hybridization Theory has been used to evaluated the LSPR and field enhancement of single and dimer Al-Al2O3-Au MDM nanostructure. Results: It is observed that the resonance mode show dependence on the thickness of Al2O3 layer and also on the composition of nanostructure. The Au layered MDM nanostructure shows two peak of equal intensities simultaneously in UV and visible region tuned to NIR region. The extinction spectra and electric field distribution profiles of dimer nanoparticles are compared with monomer to reveal the extent of coupling. The dimer configuration shows higher field enhancement ~107 at 1049 nm. By optimizing the thickness of dielectric layer the MDM nanostructure can be used over UV-visible-NIR region. Conclusion: The LSPR peak shows dependence on the thickness of dielectric layer and also on the composition of nanostructure. It has been observed that optimization of size and thickness of dielectric layer can provide two peaks of equal intensities in UV and Visible region which is advantageous for many applications. The electric field distribution profiles of dimer MDM nanostructure enhanced the field by ~107 in visible and NIR region shows its potential towards SERS substrate. The results of this study will provide valuable information for the optimization of LSPR of Al-Al2O3-Au MDM nanostructure to have high field enhancement.

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.

Scalable fabrication of in-plane microscale self-powered integrated systems for fast-response and highly selective dual-channel gas detection

Nano Energy ◽  
2021 ◽  
pp. 106253
Author(s):  
Xiaoyu Shi ◽  
Junyu Chang ◽  
Jieqiong Qin ◽  
Hanqing Liu ◽  
Xiong Zhang ◽  
...  
Keyword(s):  
Fast Response ◽  
Gas Detection ◽  
Integrated Systems ◽  
Dual Channel ◽  
Self Powered

scholarly journals Spatially Ordered Matrix of Nanostructured Tin–Tungsten Oxides Nanocomposites Formed by Ionic Layer Deposition for Gas Sensing

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4169
Author(s):  
Gennady Gorokh ◽  
Natalia Bogomazova ◽  
Abdelhafed Taleb ◽  
Valery Zhylinski ◽  
Timur Galkovsky ◽  
...  
Keyword(s):  
Tungsten Oxide ◽  
Gas Sensing ◽  
Oxide Films ◽  
High Sensitivity ◽  
Anodic Alumina ◽  
Film Deposition ◽  
Silicon Substrates ◽  
Layer By Layer ◽  
Gas Sensitivity ◽  
Nanoporous Anodic Alumina

The process of layer-by-layer ionic deposition of tin-tungsten oxide films on smooth silicon substrates and nanoporous anodic alumina matrices has been studied. To achieve the film deposition, solutions containing cationic SnF2 or SnCl2 and anionic Na2WO4 or (NH4)2O·WO3 precursors have been used. The effect of the solution compositions on the films deposition rates, morphology, composition, and properties was investigated. Possible mechanisms of tin-tungsten oxide films deposition into the pores and on the surface of anodic alumina are discussed. The electro-physical and gas-sensitive properties of nanostructured SnxWyOz films have been investigated. The prepared nanocomposites exhibit stable semiconductor properties characterized by high resistance and low temperature coefficient of electrical resistance of about 1.6 × 10−3 K−1. The sensitivity of the SnxWyOz films to 2 and 10 ppm concentrations of ammonia at 523 K was 0.35 and 1.17, respectively. At concentrations of 1 and 2 ppm of nitrogen dioxide, the sensitivity was 0.48 and 1.4, respectively, at a temperature of 473 K. At the temperature of 573 K, the sensitivity of 1.3 was obtained for 100 ppm of ethanol. The prepared nanostructured tin-tungsten oxide films showed promising gas-sensitivity, which makes them a good candidate for the manufacturing of gas sensors with high sensitivity and low power consumption.

Preparation of CuO Nanopowder in Aqueous Solution by Applying Ultrasonic and its CO Gas Sensitivity

2007 ◽  
Vol 544-545 ◽  
pp. 901-904 ◽  
Author(s):  
Ji Bum Yang ◽  
Tae Gyung Ko ◽  
Sang Jin Jung ◽  
Jae Hee Oh
Keyword(s):  
Aqueous Solution ◽  
Gas Sensing ◽  
Spherical Shape ◽  
Particle Morphology ◽  
High Yield ◽  
Ambient Conditions ◽  
Gas Sensitivity ◽  
Molar Ratios ◽  
Naoh Solution ◽  
Co Gas

We report on a process in which CuO nanopowder was produced in a high yield by adopting ultrasonic in aqueous solution. In our experiment, CuCl2 solution was reacted with NaOH solution and NaNO2, at ambient conditions applying ultrasonic for 5 min. Precipitation was performed by varying the molar ratios of NaOH/CuCl2 and NaNO2/CuCl2. CuO nanoparticles of ~ 5 nm and spherical shape were obtained at the NaOH/CuCl2 of 2.0 and the NaNO2/CuCl2 of 0.097. Without ultrasonication, an amorphous phase was formed at these conditions. This indicates that sonochemical reaction facilitates direct formation of the nanosized CuO particles. In addition, the particle morphology varied from sphere through ellipsoid to needle forms depending on pH. In thick films prepared with the CuO powder for gas sensing, the maximum CO gas sensitivity reached 93 % at the temperature of 250 °C and depended linearly on CO concentration in log scale over the range of 10 ~ 104 ppm.

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