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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
  • electropolymerization
  • polyporphyrin films
  • quartz crystal microbalance method
  • oxygen electroreduction.
应用领域
  • Applied Chemistry
机构单位
  • G.A. Krestov Institute of Solution Chemistry of RAS
  • University Union Nicola Tesla
  • Ivanovo State University of Chemistry and Technology
61 条数据
?? 中文（中国） ▾

  • Rooma??Temperature Partial Conversion of ?±a??FAPbI <sub/>3</sub> Perovskite Phase via PbI <sub/>2</sub> Solvation Enables Higha??Performance Solar Cells

    摘要： The two-step conversion process consisting of metal halide deposition followed by conversion to hybrid perovskite has been successfully applied toward producing high-quality solar cells of the archetypal MAPbI3 hybrid perovskite, but the conversion of other halide perovskites, such as the lower bandgap FAPbI3, is more challenging and tends to be hampered by the formation of hexagonal nonperovskite polymorph of FAPbI3, requiring Cs addition and/or extensive thermal annealing. Here, an efficient room-temperature conversion route of PbI2 into the α-FAPbI3 perovskite phase without the use of cesium is demonstrated. Using in situ grazing incidence wide-angle X-ray scattering (GIWAXS) and quartz crystal microbalance with dissipation (QCM-D), the conversion behaviors of the PbI2 precursor from its different states are compared. α-FAPbI3 forms spontaneously and efficiently at room temperature from P2 (ordered solvated polymorphs with DMF) without hexagonal phase formation and leads to complete conversion after thermal annealing. The average power conversion efficiency (PCE) of the fabricated solar cells is greatly improved from 16.0(±0.32)% (conversion from annealed PbI2) to 17.23(±0.28)% (from solvated PbI2) with a champion device PCE > 18% due to reduction of carrier recombination rate. This work provides new design rules toward the room-temperature phase transformation and processing of hybrid perovskite films based on FA+ cation without the need for Cs+ or mixed halide formulation.

    关键词： FAPbI3,two-step conversion,high performance,hybrid perovskite solar cells,quartz-crystal microbalance,in situ grazing incidence wide angle x-ray scattering

    更新于2025-09-16 10:30:52

  • [IEEE 2019 Joint Conference of the IEEE International Frequency Control Symposium anEuropean Frequency and Time Forum (EFTF/IFC) - Orlando, FL, USA (2019.4.14-2019.4.18)] 2019 Joint Conference of the IEEE International Frequency Control Symposium and European Frequency and Time Forum (EFTF/IFC) - Laser Treatment of Quartz Crystal Blanks for the Modification of Properties of Resonators

    摘要： It is known that quartz crystal blanks have to go through many procedures of mechanical processing for the exact configuration to ensure precise geometry for expected involving mechanical performance. processing are widely used for the shaping and reduction in sizes could be done with laser beams to satisfy the objectives. Given the fact laser beams can be speedy and cleaner in the process, it is imaginable that some mechanical processing procedures can be replaced by laser radiation or other energy methods at a lower cost. To this goal, we use laser with different strengths and durations to scan the selected surface areas of blanks of quartz crystal to change the property of exposed portions with noticeable changes. After validation of the laser processing, we started scanning quartz crystal blanks of resonators for improvements. The experiments showed that with properly designed radiation pattern and areas, we should be able to use the laser treatment as part of the manufacturing process to innovate the existing process and products.

    关键词： Quartz,Laser,Radiation,Resonator,Ablation

    更新于2025-09-12 10:27:22

  • Quartz Optical Fibers with Increased Content of Fluorine for Fluorimeter Probes

    摘要： A method to fabricate quartz optical fibers for probes employed in fluorescence diagnostics of tumors is proposed. It is shown that the sensitivity of fluorimeters in the near-IR spectral range can be increased using quartz–quartz optical fiber probes with the core made of the Heraeus glass and the SiO2–F cladding with an increased content of fluorine in the glass of up 7 wt %. The numerical aperture of such optical fibers amounts to 0.32. The optical fibers are used to develop a prototype of a multifiber high-aperture probe for a laser oncofluorimeter with a relatively high sensitivity in a spectral interval of 900–1100 nm.

    关键词： fluorimeter probes,fluorescence diagnostics,quartz optical fibers,fluorine,near-IR spectral range

    更新于2025-09-12 10:27:22

  • Implementation of a tunable hybrid system with coupled high Q-factor resonators based on mode localization for sensing purposes

    摘要： There has been a growing interest in the development of MEMS devices based on Anderson mode localization to increase the sensitivity to mass perturbation in the last decade [1–7]. Mode localization occurs within an array of weakly coupled identical resonators in which a mass or sti?ness perturbation is introduced. The main strengths of mode localization are its high sensitivity to the perturbation and the common mode rejection [8]. However, taking advantage of this phenomenon requires to have an array of perfectly identical resonators and a low coupling sti?ness, but high enough to avoid mode aliasing [9]. As a consequence, microfabrication defects are often an obstacle to the implementation of such sensitive sensors. In addition, the devices geometry and the chosen excited mode are limited by the implementation of the coupling (for instance the ?rst mode of double-ended tuning forks [4] or cantilevers [5]). Therefore, we hereby suggest an alternative with a system based on a ?rst mechanical resonator coupled to a second resonator having a di?erent physical nature that allows to tune it. Such a hybrid approach has already been investigated for MEMS characterization using electrical resonators [10] having a Q-factor of 1000 and we previously demonstrated the possibility to generate modes in a system made of an electrical resonator having a Q-factor of 20 and a digital device [11]. In this work and for the ?rst time to our knowledge, we set up a two-degree-of-freedom (DoF) coupled system made of piezoelectric resonators (QCM) with Q-factors exceeding 105. The coupling and one of the coupled resonators are replaced by their digital equivalent (based on dynamic equations) and implemented in a hardware performing real time calculations. This method enables to tune the design parameters of one resonator and the coupling coe?cient in order to reach the optimal conditions for mode localization, and to get rid of the geometric constraints imposed by the design of the coupling (thus allowing to work with a QCM for instance). Since such piezoelectric resonators are broadly used the ?eld of mass sensors for agro-food, environment, safety or health applications [12], these results pave the way to a new generation of ultrasensitive biosensors.

    关键词： ?eld programmable gate array,Tunable hybrid system,weak coupling,quartz crystal microbalance,mode localization,digital resonator

    更新于2025-09-12 10:27:22

  • [IEEE 2019 IEEE/MTT-S International Microwave Symposium - IMS 2019 - Boston, MA, USA (2019.6.2-2019.6.7)] 2019 IEEE MTT-S International Microwave Symposium (IMS) - Miniaturized Quartz Waveguide Filter using Double-Folded Structure

    摘要： A miniaturized 28 GHz quartz waveguide band-pass filter using a double-folded structure has been developed. The double-folded structure is used for a footprint reduction less than half of a current single-folded quartz waveguide filter. Some analyses using EM simulation were carried out for studying an electromagnetic coupling between the waveguide resonators. For the double-folded structure, an inductive coupling is appropriate for a main coupling in the vertical direction. The fabricated filter, an 8-pole Chebyshev BPF, has a size of 6.9 × 7.2 × 3.1 mm3 and measured insertion loss was very low such as 0.74 dB which is same as the current single-folded type. Besides, an 8-pole quasi-elliptic BPF was simulated and its attenuation performance was remarkably improved.

    关键词： TE mode,cross-coupling,double-folded waveguide filter,millimeter wave,transmission zero,quartz

    更新于2025-09-12 10:27:22

  • Phototransferred thermoluminescence of annealed synthetic quartz: Analysis of illumination-time profiles, kinetics and competition effects

    摘要： Phototransferred thermoluminescence (PTTL) induced from annealed synthetic quartz using 470 nm blue light is reported. The quartz was annealed at 900oC for 10, 30 and 60 minutes prior to use. A glow curve of conventional TL measured at 1oC s-1 following irradiation to 200 Gy for the sample annealed for 10 minutes shows six peaks at 90, 122, 176, 210, 240 and 340oC. The sample annealed for 30 minutes has peaks at 80, 110, 136, 196, 240 and 330oC. Similarly, the sample annealed for 60 minutes also has six peaks at 80, 120, 134, 188, 235 and 340oC. For ease of reference, these are labelled I-VI respectively. Peaks observed under PTTL are referred to as A1 onwards. Of the six peaks, only the first three are reproduced under phototransfer for the sample annealed for 60 minutes. When the duration of annealing was reduced to 10 minutes, PTTL is induced only at peaks A1 and A3. Interestingly, for the intermediate duration of annealing of 30 minutes, the only peak that appears under phototransfer is the first one, A1. For quartz annealed for 10 minutes, the PTTL appears as long as the preheating temperature does not exceed 560oC. On the other hand, in the quartz annealed for 30 and 60 minutes, PTTL only appears for preheating to and below 450oC. This shows that the occupancy of deep electron traps at temperatures beyond 450 or 560oC is low in the said samples. The activation energy for peaks A1 and A3 was found to be about 0.68 eV. The PTTL peaks were studied for thermal quenching and peaks A1 and A3 were determined to be subject to this effect. The activation energy for thermal quenching was determined as 0.62 ± 0.04 eV in analysis using peak A1. In all cases, the PTTL intensity goes through a peak as a function of illumination time. The experimental dependence of PTTL intensity on illumination time is modelled using sets of coupled linear differential equations based on systems of donors and acceptors whose number is determined by preheating temperature. Competition effects involved in the PTTL have been discussed.

    关键词： competition effects,phototransferred thermoluminescence,synthetic quartz,Annealing,thermal quenching

    更新于2025-09-12 10:27:22

  • Phototransferred thermoluminescence from natural quartz annealed at 1000?°C: Analysis of time-dependent evolution of intensity and competition effects

    摘要： Phototransferred thermoluminescence (PTTL) related to multiple acceptors and donors in natural quartz is reported. A glow curve measured at 1 °C s?1 after beta irradiation to 300 Gy has four peaks labelled I, II, III, and IV at 70, 124, 170, and 298 °C respectively. Preparatory to measurement of PTTL, these peaks were removed in turn by preheating to 100, 140, 250 and 500 °C. PTTL is observed for peak I after any of these preheating temperatures. This means that peak I is reproduced, under phototransfer, when any of peak I, II, III or IV has been removed. Peak II is only reproduced after preheating to 250 °C to remove peaks I, II and III. Peak II does not re-appear after any preheating beyond 250 °C. Peak III re-appears under phototransfer following preheating to either 250 or 500 °C. No PTTL was observed for peak IV at all. The behaviour of peaks II and IV are suggestive of competition effects that merit investigation. This is addressed in this report. The dependence of PTTL intensity on the duration of illumination is studied for all PTTL peaks corresponding to various preheating temperatures. Peak I shows an initial increase in intensity followed by a decrease with illumination for preheating to 100, 140 and 500 °C. However when the sample is preheated to 250 °C, the intensity decreases monotonically. The PTTL intensity for peaks II and III go through a slow and extended growth up to 1500 s before the onset of any decrease. The change of intensity with illumination time is modelled using coupled first-order linear differential equations on the basis of systems of acceptors and donors whose number depends on the preheating temperature.

    关键词： Models,Donors,Acceptors,Competition effects,Phototransferred thermoluminescence,Natural quartz

    更新于2025-09-12 10:27:22

  • [IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Photoacoustic Spectroscopy Sensor with a Small-Gap Quartz Tuning Fork

    摘要： Quartz tuning fork (QTF), a mature electric device which is widely used in electronic circuits for timing reference, has been investigated in photoacoustic spectroscopy in recent years. Due to the excellent immunity, high Q-factor, and compactness, utilizing a QTF for acoustic wave detection in photoacoustic spectroscopy, namely quartz-enhanced photoacoustic spectroscopy (QEPAS), is a significant innovative spectroscopy. In a QEPAS system, the QTF’s distance of the fork tines, the so-called gap, determines the space for acoustic wave generation. Traditional QTFs with a gap of 300 μm can satisfy the requirement when the excitation source which locates in the near-infrared spectrum range. While, some custom-made QTFs has been investigated to accommodate the mid-infrared laser with beam larger than ~400-500 μm [1,2]. Nevertheless, in the near-infrared range, the diameter of the laser beam is far smaller than that in the mid-infrared spectral range. When a QTF applied in the QEPAS system, the laser beam passes through the fork valley and excites the gas molecules. Notably, the acoustic wave generated by the reaction between the laser beam and the gas molecules can be viewed as spherical wave oscillation. The spherical wave propagation decreases with the cube of the distance, which suggests that the energy of the sound wave will diminish rapidly as the distance from the generation source point of the sound wave increases. So, employing a small-gap QTF can avoid energy losses and therefore improve the signal level of the QEPAS sensor. In this paper, a custom-made QTF with a small-gap of 200 μm used in the QEPAS sensor was demonstrated. A simulation of the optimal vertical position with respect to the QTF and the length of micro-resonator were developed by using the COMSOL Multiphysics. The experiment was also conducted and indicated that such a small-gap QTF has an improved performance in the QEPAS sensor system.

    关键词： photoacoustic spectroscopy,acoustic wave detection,QEPAS,quartz tuning fork,small-gap

    更新于2025-09-12 10:27:22

  • A model for real time, <i>in situ</i> estimation of cesium coverage on metal substrate using infrared imaging under vacuum

    摘要： The present work is to develop an infra-red (IR) camera based in situ diagnostic tool for the determination of cesium (Cs) coverage suitable for ion source applications. Cs seeding is done to reduce the surface work function that enhances the surface assisted negative hydrogen ion production. The temporal Cs deposition on a metal surface (for, e.g., tungsten or molybdenum) follows Langmuir adsorption isotherm (LAI) kind of behavior. The surface temperature varies while the Cs deposition is reflected in the IR camera temperature measurements for a constant surface emissivity value. In this paper, a model on the relationship between Cs coverage in correlation with surface emissivity and temperature variation based on the theory of LAI is presented. A surface ionization probe (SIP) in the form of a cathode-anode assembly together with an IR camera viewing arrangement is designed to measure the Cs flux and the surface temperature simultaneously to test our model. In the present experiment, the Cs flux measurement using SIP is validated with a standard quartz crystal microbalance (QCM). The proposed model would be useful to correlate Cs coverage on plasma grid-like surface conditions under negative ion source relevant vacuum conditions.

    关键词： surface ionization probe,infra-red camera,cesium coverage,quartz crystal microbalance,Langmuir adsorption isotherm

    更新于2025-09-12 10:27:22

  • Application of Quartz Tuning Fork in Photodetector Based on Photothermal Effect

    摘要： A photodetector with a commercial quartz tuning fork (QTF) based on photothermal effect was demonstrated. Unlike the commonly used thermosensitive elements, a QTF with the mechanical resonance ability and the piezoelectric effect was used to amplify the photothermal signal. Operating at the optimal operating distance and modulation signal duty ratio selected for the photodetector, the photodetector achieved a good linear response at the wavelength of 1550 nm and 980 nm. And the photoresponsivity of the photodetector reach up to 515 mV/mW at the wavelength of 1550 nm. More important, the detection sensitivity of 0.75 pW at 203 s integration time has been achieved by using the Allan deviation analysis.

    关键词： photothermal effect,Photodetector,quartz tuning fork

    更新于2025-09-12 10:27:22