Near Room Temperature Sensing by In₂O₃ Decorated Silicon Nanowires for Sensitive Detection of Ethanol
15 Mar 2021-IEEE Sensors Journal (Institute of Electrical and Electronics Engineers (IEEE))-Vol. 21, Iss: 6, pp 7275-7282
TL;DR: In this paper, the role of indium trioxide (In2O3) decorated Si nanowires (SiNWs) based resistive sensor for selective detection of ethanol vapors at near room temperature has been successfully demonstrated.
Abstract: The role of indium trioxide (In2O3) decorated Si nanowires (SiNWs) based resistive sensor for selective detection of ethanol vapors at near room temperature has been successfully demonstrated. SiNWs samples were synthesized using metal assisted chemical etching technique and these were decorated by a thin film of indium followed by annealing. The sensing response was captured by measuring the change in resistance of the sensing layer using a Cr-Au inter-digitated-electrode (IDE) structure formed on top of the sensing layers. All sensors were tested for ethanol, acetone, iso-propanol (IPA), xylene, benzene and toluene vapours in the wide concentration range of 5–500 ppm and at different temperatures. Sensors based on SiNWs alone had displayed higher response towards acetone vapours whereas after heterojunction formation with In2O3, significant sensitivity to ethanol was depicted. In2O3 decorated SiNWs resulted in significant enhancement of the sensor response% towards ethanol at near room temperature. Minimum detection of ethanol at 50 ppm and 10 ppm was portrayed by SiNWs and In2O3/SiNWs based sensors respectively. It was concluded that sensing behaviour was a consequence of combinatory effect produced by the presence of both SiNWs and In2O3. A simple explanation with device schematic and band diagrams of the material are proposed to describe the sensing mechanism. This study demonstrates the significance of surface treatment of SiNWs and the role of heterostructures for tuning the sensing properties and development of wafer scalable sensors.
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TL;DR: In this paper , a flexible silicon nanowires (SiNWs) sensor for detecting gaseous acetone with a concentration as low as 0.1 parts per million (ppm) at flat and bending states was presented.
Abstract: Acetone commonly exists in daily life and is harmful to human health, therefore the convenient and sensitive monitoring of acetone is highly desired. In addition, flexible sensors have the advantages of light-weight, conformal attachable to irregular shapes, etc. In this study, we fabricated high performance flexible silicon nanowires (SiNWs) sensor for acetone detection by transferring the monocrystalline Si film and metal-assisted chemical etching method on polyethylene terephthalate (PET). The SiNWs sensor enabled detection of gaseous acetone with a concentration as low as 0.1 parts per million (ppm) at flat and bending states. The flexible SiNWs sensor was compatible with the CMOS process and exhibited good sensitivity, selectivity and repeatability for acetone detection at room temperature. The flexible sensor showed performance improvement under mechanical bending condition and the underlying mechanism was discussed. The results demonstrated the good potential of the flexible SiNWs sensor for the applications of wearable devices in environmental safety, food quality, and healthcare.
4 citations
TL;DR: In this paper , the synthesis of a low-cost ultra-thin silicon nanowires (Si NWs)-based sensor is reported, which allows the detection of various dangerous gases such as acetone, ethanol, and the ammonia test as a proof of concept in a nitrogen-based mixture.
Abstract: Air quality monitoring is an increasingly debated topic nowadays. The increasing spillage of waste products released into the environment has contributed to the increase in air pollution. Consequently, the production of increasingly performing devices in air monitoring is increasingly in demand. In this scenario, the attention dedicated to workplace safety monitoring has led to the developing and improving of new sensors. Despite technological advancements, sensors based on nanostructured materials are difficult to introduce into the manufacturing flow due to the high costs of the processes and the approaches that are incompatible with the microelectronics industry. The synthesis of a low-cost ultra-thin silicon nanowires (Si NWs)-based sensor is here reported, which allows us the detection of various dangerous gases such as acetone, ethanol, and the ammonia test as a proof of concept in a nitrogen-based mixture. A modified metal-assisted chemical etching (MACE) approach enables to obtain ultra-thin Si NWs by a cost-effective, rapid and industrially compatible process that exhibit an intense light emission at room temperature. All these gases are common substances that we find not only in research or industrial laboratories, but also in our daily life and can pose a serious danger to health, even at small concentrations of a few ppm. The exploitation of the Si NWs optical and electrical properties for the detection of low concentrations of these gases through their photoluminescence and resistance changes will be shown in a nitrogen-based gas mixture. These sensing platforms give fast and reversible responses with both optical and electrical transductions. These high performances and the scalable synthesis of Si NWs could pave the way for market-competitive sensors for ambient air quality monitoring.
1 citations
TL;DR: In this paper , the authors presented an efficient, highly responsive and highly repeatable MoS 2 /SiNWs heterostructure based photodetector, which was constructed using a scalable fabrication process.
References
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TL;DR: In this paper, structural and Raman spectroscopy measurements of pure and Sn-doped In2O3 nanowires were performed to obtain the phonon modes and confirm compositional and structural information given by structural characterization.
Abstract: In this work we report on structural and Raman spectroscopy measurements of pure and Sn-doped In2O3 nanowires. Both samples were found to be cubic and high quality single crystals. Raman analysis was performed to obtain the phonon modes of the nanowires and to confirm the compositional and structural information given by structural characterization. Cubic-like phonon modes were detected in both samples and their distinct phase was evidenced by the presence of tin doping. As a consequence, disorder effects were detected evidenced by the break of the Raman selection rules.
151 citations
TL;DR: A dramatic enhancement in ethanol sensing characteristics of NiO hollow nanostructures via decoration with In2O3 nanoclusters is reported and the 90% recovery time was drastically reduced from 1880 to 23 s, and a selective detection of ethanol with negligible cross-response to other gases was achieved.
Abstract: In this work, we report a dramatic enhancement in ethanol sensing characteristics of NiO hollow nanostructures via decoration with In2O3 nanoclusters. The pure NiO and 1.64-4.41 atom % In-doped NiO and In2O3-decorated NiO hollow spheres were prepared by ultrasonic spray pyrolysis, and their gas sensing characteristics were investigated. The response (the ratio between the resistance in gas and air) of the In2O3-decorated NiO hollow spheres to 5 ppm ethanol (C2H5OH) was 9.76 at 350 °C, which represents a significant improvement over the In-doped NiO and pure NiO hollow spheres (3.37 and 2.18, respectively). Furthermore, the 90% recovery time was drastically reduced from 1880 to 23 s, and a selective detection of ethanol with negligible cross-response to other gases was achieved. The enhanced gas response and fast recovery kinetics were explained in relation to the thinning of the near-surface hole accumulation layer of p-type NiO underneath n-type In2O3, the change of charge carrier concentration, and the variation of oxygen adsorption.
144 citations
TL;DR: A chemical-sensitive field-effect transistor (CS-FET) platform based on 3.5-nm-thin silicon channel transistors demonstrates a low-power, sensitive, and selective multiplexed gas sensing technology by detecting H2S, H2, and NO2 at room temperature for environment, health, and safety in the oil and gas industry.
Abstract: There is great interest in developing a low-power gas sensing technology that can sensitively and selectively quantify the chemical composition of a target atmosphere. Nanomaterials have emerged as extremely promising candidates for this technology due to their inherent low-dimensional nature and high surface-to-volume ratio. Among these, nanoscale silicon is of great interest because pristine silicon is largely inert on its own in the context of gas sensing, unless functionalized with an appropriate gas-sensitive material. We report a chemical-sensitive field-effect transistor (CS-FET) platform based on 3.5-nm-thin silicon channel transistors. Using industry-compatible processing techniques, the conventional electrically active gate stack is replaced by an ultrathin chemical-sensitive layer that is electrically nonconducting and coupled to the 3.5-nm-thin silicon channel. We demonstrate a low-power, sensitive, and selective multiplexed gas sensing technology using this platform by detecting H2S, H2, and NO2 at room temperature for environment, health, and safety in the oil and gas industry, offering significant advantages over existing technology. Moreover, the system described here can be readily integrated with mobile electronics for distributed sensor networks in environmental pollution mapping and personal air-quality monitors.
142 citations
TL;DR: In this article, the authors developed a fast and highly sensitive chemiresistive sensor based on the nanocomposite of polysaccharide (guar gum) and gold nanoparticles for the room temperature detection of ammonia in the range of 0.1 parts-per-quadrillion (ppq) to 75,000 partsper-million (ppm).
Abstract: We have developed a fast and highly sensitive chemiresistive sensor based on the nanocomposite of polysaccharide (guar gum) and gold nanoparticles for the room temperature detection of ammonia in the range of 0.1 parts-per-quadrillion (ppq) to 75 000 parts-per-million (ppm). Sensor response, selectivity, and stability studies reveal excellent sensing of the nanocomposite. The room temperature operation under ambient conditions and the wide range sensing indicates that the composites can be explored for environmental as well as biomedical applications. We have for the first time quantified the ammonia level released from the urine and blood serum of human beings using the resisitive sensor. The urine ammonia level was found to be ∼24 000 ppm and is higher for patients with renal problems. This demonstrated the utility of the sensor for health monitoring.
141 citations
TL;DR: The enhanced NO2 sensing performances were attributed to the synergistic effect of uniformly distributed In2O3 cubes and graphene sheets in the unique hybrid architectures without the interfering of extra additives.
Abstract: In this report, we developed an additive-free synthesis of In2O3 cubes embedded into graphene networks with InN nanowires (InN-NWs) and graphene oxide (GO) as precursors by a facile one-step microwave-assisted hydrothermal method. In absence of GO, the InN-NWs maintained their chemical composition and original morphology upon the same treatment. At varying mass ratios of InN-NWs and GO, the different morphologies and distributions of In2O3 could be obtained on graphene sheets. The uniform distribution, which is usually considered favorable for enhanced sensing performance, was observed in In2O3 cubes/reduced graphene oxide (rGO) composites. The room-temperature NO2 sensing properties of the In2O3 cubes/rGO composites-based sensor were systematically investigated. The results revealed that the sensor exhibited a significant response to NO2 gas with a concentration lower to 1 ppm, and an excellent selectivity, even though the concentrations of interferential gases were 1000 times that of NO2. The enhanced NO2 sensing performances were attributed to the synergistic effect of uniformly distributed In2O3 cubes and graphene sheets in the unique hybrid architectures without the interfering of extra additives.
116 citations