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oe1(光电查) - 科学论文

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出版时间
  • 2018
研究主题
  • interdigital resonator
  • microwave gas sensor
  • PSE-coated
应用领域
  • Optoelectronic Information Science and Engineering
机构单位
  • King Mongkut’s University of Technology North Bangkok
  • Rajamangala University of Technology Suvarnabhumi
571 条数据
?? 中文(中国)
  • Progresses in Chemical Sensor || Air-Suspended Silicon Micro-Bridge Structures for Metal Oxide- Based Gas Sensing

    摘要: Maintaining specific temperature is a key parameter for most of the gas sensing materials, particularly for metal oxide-based thin film layers, to operate them more efficiently to detect different gaseous (or vapor) species at ppm and ppb concentration levels. For field applications, battery-operated micro-gas-sensors, power dissipation and the required temperature stability are to be maintained with a close tolerance for better signal stability and also to analyze the generated data from the sensing element. This chapter mainly focuses on several metal oxide films to highlight the base temperature and its creation on silicon-based platforms. Air-suspended structures are highlighted, and a comparison is drawn between simple and MEMS-based structures from the power dissipation point of view. Ease of fabrication and operation limitations are explained with fabrication issues.

    关键词: Platinum resistance thermometer,Gas sensing devices,Platinum micro-heater,Surface micromachining,MEMS,Metal oxide thin films

    更新于2025-09-09 09:28:46

  • [IEEE 2018 28th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) - Greifswald, Germany (2018.9.23-2018.9.28)] 2018 28th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) - Nitriding of Austenitic, Martensitic and Pearlitic Steels in Hydrogen-Contain Glow Discharge Plasma

    摘要: The effect of a working gas medium containing argon, nitrogen and hydrogen in the range of 10-30% is investigated for nitriding in a glow discharge on the microstructure and microhardness of the surface layer of austenitic, martensitic and pearlitic steels. It is shown that when up to 15% of hydrogen is added to the working gas mixture, it is possible to increase the kinetics of growth of the modified layer in the austenite and martensitic steels almost two times. It is found that when the concentration of hydrogen in the gas mixture is above 15%, it leads to the formation of microcracks in the near-surface areas of high-alloy steels after treatment.

    关键词: nitriding of steels,hydrogen contain gas mixture,surface ion modification

    更新于2025-09-09 09:28:46

  • Near-Room-Temperature Ethanol Gas Sensor Based on Mesoporous Ag/Zn-LaFeO <sub/>3</sub> Nanocomposite

    摘要: The rational design of heterojunction between different metal oxides with mesoporous structures has attracted tremendous attention due to their special physicochemical properties and vital importance for practical applications. In this paper, mesoporous Ag/Zn–LaFeO3 nanocomposite is successfully synthesized through a facile nanocasting technique using KIT-6 as a hard template in sol–gel route and used as sensing materials to achieve an exceptionally sensitive and selective detection of trace ppm-level ethanol. The obtained composite possesses high surface area and exhibits excellent sensing response (64.2 for 100 ppm) to ethanol at near-room with relatively fast response/recovery time. When tested with the concentrations as low as 5 ppm, it also shows a remarkably high selectivity to the ethanol, but only minor responses to other interfering gases. These enhanced gas-sensing properties are attributed to the combination of mesoporous nanostructure and Ag/Zn–LaFeO3 heterogeneous composites.

    关键词: mesoporous,ethanol,gas sensors,near-room temperature,Ag/Zn–LaFeO3 nanocomposite

    更新于2025-09-09 09:28:46

  • [IEEE 48th European Solid-State Device Research Conference (ESSDERC 2018) - Dresden (2018.9.3-2018.9.6)] 2018 48th European Solid-State Device Research Conference (ESSDERC) - Towards IC-based quantum sensing - recent achievements and future research trends

    摘要: This paper describes some of the recent trends in the use of integrated circuit (IC) technology for the design of smart quantum sensors. To this end, after a brief introduction into the topic of quantum sensing including its intrinsic advantages and associated challenges, a number of emerging applications including the fields of IC-based inductive electron and nuclear spin detection as well as Rydberg gas sensing and NV center based sensing are used to highlight the great potential of the IC-based quantum sensing approach.

    关键词: integrated circuit,quantum sensing,NV center based sensing,inductive electron and nuclear spin detection,smart quantum sensors,Rydberg gas sensing

    更新于2025-09-09 09:28:46

  • Aerosol synthesis of germanium nanoparticles supported by external seeding: Theoretical and experimental analysis

    摘要: In this work we present a detailed study of the effect of heterogeneous nucleation on the formation of germanium nanoparticles (Ge NPs) produced from monogermane (GeH4) in a hot wall reactor gas phase synthesis. As external seeding unit we use a hot wire generator (HWG) which produces a stable concentration of aerosol particles. The particle concentration and size of the seeds is easily controllable via the applied voltage and used metal. We demonstrate the importance of seed particles for the production of narrowly distributed Ge NPs with geometrical standard deviations (GSD) < 1.1 in our setup. Thereby, molybdenum and tungsten as wire metal show the best seeding results. The size of the final Ge NPs can be precisely controlled in the range of 20 to 60 nm. The expansion of Ge lattice seen in XRD and tiny amount of Mo probed by high-resolution STEM-EDXS analysis indicate that the Mo seed particles are most likely dissolved and incorporated in the Ge lattice during growth. Furthermore, we demonstrate an approach to investigate the effect of heterogeneous nucleation on the particle formation by population balance modeling. The results are in good agreement with experimental data. The seed concentration is the key parameter and has a major influence on the nucleation rate.

    关键词: Germanium,Nanoparticles,Simulation,Hot wire generator,Gas phase synthesis,Heterogeneous nucleation

    更新于2025-09-09 09:28:46

  • Gas Sensing Characterization of Single-Nanowire Sensor Array Systems Based on Non-Functionalized and Pt-Functionalized Tungsten Oxide

    摘要: Here we present the gas sensing characterization of single-nanowire sensor array systems based on either non-functionalized or Pt-functionalized single tungsten oxide nanowires towards various concentrations of nitrogen dioxide and ethanol. The sensor systems demonstrate stable and reproducible responses to the tested analytes, showing consistency with previous systems based on multiple-nanowire based films and validating the fabrication process of these devices.

    关键词: sensor array,single-nanowire,tungsten oxide,gas sensing

    更新于2025-09-09 09:28:46

  • Analytical Gate Capacitance Models for Large-Signal Compact Model of AlGaN/GaN HEMTs

    摘要: In this paper, analytical gate capacitance models for a large-signal compact model of AlGaN/GaN high-electron mobility transistors are proposed. Different from the MOSFET devices, different depletion regions on either side of the gate are fully considered for high-voltage GaN devices. The depletion regions are bias-dependent to implement the capacitance models into the large-signal compact model. A transfer function is proposed to characterize the switching behavior of the capacitances between on- and off-states, which is essential to describe all the states of a device, for example, operating at Class-B. Different from previous works, the current saturation phenomenon is taken into account in determining the intrinsic capacitances which are induced by nonstatic channel charge. The capacitance models can be easily implemented into the virtual-source-based model to accurately predict the S-parameters and large-signal output characteristics.

    关键词: intrinsic capacitances,2-D electron gas (2DEG)-electrode fringing capacitances,AlGaN/GaN high-electron mobility transistors (HEMTs),large-signal compact model

    更新于2025-09-09 09:28:46

  • Nitric Oxide Detector Based on WO <sub/>3</sub> -1wt%In <sub/>2</sub> O <sub/>3</sub> -1wt%Nb <sub/>2</sub> O <sub/>5</sub> with State-of-the-Art Selectivity and ppb-Level Sensitivity

    摘要: Fast, sensitive, and precise detection of nitric oxide (NO) is critical to many applications in environmental monitoring and early disease diagnosis via respiratory testing. An effective detection system requires a sensor to detect NO gas at the parts per billion (ppb) level, and this system should possess a high degree of anti-interference selectivity. To achieve these targets, a series of gas sensor thin films based on intrinsic WO3, one-additive-doped WO3 (prepared by doping In2O3 or Nb2O5), and two-additive-doped WO3 (synthesized by doping with In2O3 and Nb2O5) oxides were successfully grown. By analyzing the properties of sensitivity, selectivity, responsiveness, and recovery time of the gas sensors, we found that WO3-1wt%In2O3-1wt%Nb2O5 has overwhelming advantages over intrinsic WO3, WO3-In2O3, and WO3-Nb2O5. A sensing response value of 2.4 was observed for NO concentrations as low as 20 ppb from the WO3-1wt%In2O3-1wt%Nb2O5 sensor. With 100 ppb NO gas, the WO3-1wt%In2O3-1wt%Nb2O5 sensor achieved a high response of 56.1 at 70 °C, which is a state-of-the-art performance for NO detection at low working temperature settings. WO3-1wt%In2O3-1wt%Nb2O5 also yields significantly improved selectivity and stability over intrinsic WO3, WO3-In2O3, and WO3-Nb2O5. Studies on the sensing mechanism show that the grain size, rather than the n?n heterostructure effect, plays a dominant role in the observed results. By decreasing the grain size so that it is close to the thickness of the space-charge layer, the sensing response is enhanced. Although room remains to further improve the sensing properties, the performance of WO3-1wt%In2O3-1wt%Nb2O5 is sufficient for implementation in low-content NO detection devices.

    关键词: codoping,high selectivity,NO gas sensor,limit of detection (LOD),ppb-level response,pulsed laser deposition (PLD)

    更新于2025-09-09 09:28:46

  • Core-Shell Electrospun Polycrystalline ZnO Nanofibres for Ultra-Sensitive NO2 Gas Sensing

    摘要: This paper discusses the growth of polycrystalline, self-supporting ZnO nanofibres which can detect nitrogen dioxide (NO2) gas down to 1 part per billion (ppb), one of the smallest detection limits reported for NO2 using ZnO. A new and innovative method has been developed for growing polycrystalline ZnO nanofibres. These nanofibres have been created using core-shell electrospinning of inorganic metal precursor zinc neodecanoate, where growth occurs at the core of the nanofibres. This process produces contamination-free, self-supporting, polycrystalline ZnO nanofibres of the average diameter and grain size 50 nm and 8 nm respectively, which are ideal for gas sensing applications. This process opens up an exciting opportunity for creating nanofibres from a variety of metal oxides, facilitating many new applications especially in the areas of sensors and wearable technologies.

    关键词: NO2 gas sensing,polycrystalline fibres,ZnO nanofibres,Electrospinning

    更新于2025-09-09 09:28:46

  • Extreme-ultraviolet refractive optics

    摘要: Refraction is a well-known optical phenomenon that alters the direction of light waves propagating through matter. Microscopes, lenses and prisms based on refraction are indispensable tools for controlling light beams at visible, infrared, ultraviolet and X-ray wavelengths1. In the past few decades, a range of extreme- ultraviolet and soft-X-ray sources has been developed in laboratory environments2–4 and at large-scale facilities5,6. But the strong absorption of extreme-ultraviolet radiation in matter hinders the development of refractive lenses and prisms in this spectral region, for which reflective mirrors and diffractive Fresnel zone plates7 are instead used for focusing. Here we demonstrate control over the refraction of extreme- ultraviolet radiation by using a gas jet with a density gradient across the profile of the extreme-ultraviolet beam. We produce a gas- phase prism that leads to a frequency-dependent deflection of the beam. The strong deflection near to atomic resonances is further used to develop a deformable refractive lens for extreme-ultraviolet radiation, with low absorption and a focal length that can be tuned by varying the gas pressure. Our results open up a route towards the transfer of refraction-based techniques, which are well established in other spectral regions, to the extreme-ultraviolet domain.

    关键词: lens,refractive optics,extreme-ultraviolet,prism,gas jet

    更新于2025-09-09 09:28:46