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基于SPR的液晶填充双D型PCF双参量传感器设计

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光学学报 2024年第9期44卷 255-265页

作者：范振凯孟俊皓褚世超河北科技大学信息科学与工程学院

提出了一种基于表面等离子体共振（SPR）原理的液晶填充的双D型光子晶体光纤（PCF）传感器，用于温度和折射率（RI）的双重检测。选用金作为金属对PCF中的两个大开环以及第二包层的4个气孔进行镀膜以激发SPR现象，实现了外部传感与内部... 详细信息

提出了一种基于表面等离子体共振（SPR）原理的液晶填充的双D型光子晶体光纤（PCF）传感器，用于温度和折射率（RI）的双重检测。选用金作为金属对PCF中的两个大开环以及第二包层的4个气孔进行镀膜以激发SPR现象，实现了外部传感与内部传感的结合，并进一步增强了SPR效应。为了实现温度与RI的双重检测，将温敏材料液晶E7填入中央大气孔形成纤芯，进而提升温度传感性能，通过上下两侧的大开环与待测分析液的接触实现折射率传感。使用全矢量有限元法，在完美匹配层条件下对传感性能进行了分析，并研究了中央液晶孔、小气孔及普通气孔的大小对传感性能的影响。仿真结果表明，所设计的传感器在温度为15～50℃、折射率为1.48～1.55的检测范围内具有良好的温度和RI传感性能。

关键词：传感器光子晶体光纤表面等离子体共振双重检测传感器双D型液晶

Associative learning of a three-terminal memristor network for digits recognition

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Science China(Information Sciences) 2023年第2期66卷 209-218页

作者： Yiming REN Bobo TIAN Mengge YAN Guangdi FENG Bin GAO Fangyu YUE Hui PENG Xiaodong TANG Qiuxiang ZHU junhao chu chungang DUAN Key Laboratory of Polar Materials and Devices (MOE) Ministry of Education Department of ElectronicsEast China Normal University Zhejiang Lab Institute of Microelectronics Beijing Innovation Center for Future Chips (ICFC) Tsinghua University Collaborative Innovation Center of Extreme Optics Shanxi University

Imitating the associative intelligence of the biological brain is attractive but is poorly achieved in hardware because the complex tunable connection in neural networks is difficult to reproduce. We develop a circuit composed of a three-terminal memristor network to reproduce the biological conditioning process artificially. The synaptic weight between co-firing neurons is strengthened simultaneously by generating a feedback signal from the integrate-and-fire neuron to the gate of the synaptic memristor. The network allows the multi-associative capacity of recalling more than one digit in one circuit. Both single and multi-associative learning for recalling digital images are achieved. Furthermore, all 10 digital images from “0” to “9” are successfully recalled in an associative network with such paralleling circuits. Assisted by this associative layer, a typical classification network effectively improves the recognition rate for fragmentary digital images.Our work sheds light on brain-inspired artificial associative memory and provides a strategy for applications,such as object recognition with partial features and similar scenes.

关键词： artificial intelligence associative learning memristor classification network

Ultrathin NiO/Ni_(3)S_(2)Heterostructure as Electrocatalyst for Accelerated Polysulfide Conversion in Lithium-Sulfur Batteries

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Energy & Environmental Materials 2023年第6期6卷 182-190页

作者： chunqiao Jin Pengbo Zhai Jianli Tang Liuxiang Huo Qianqian He Yan Ye Lingxi Qiu Kai Jiang Liyan Shang Yawei Li Yongji Gong Zhigao Hu junhao chu Department of Materials School of Physics and Electronic ScienceTechnical Center for Multifunctional Magneto-Optical Spectroscopy(Shanghai)Engineering Research Center of Nanophotonics&Advanced Instrument(Ministry of Education)East China Normal UniversityShanghai 200241China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan Shanxi 030006China School of Materials Science and Engineering Beihang UniversityBeijing 100191China

The practical application of Lithium-Sulfur batteries largely depends on highly efficient utilization and conversion of sulfur under the realistic condition of high-sulfur content and low electrolyte/sulfur ratio.Rational design of heterostructure electrocatalysts with abundant active sites and strong interfacial electronic interactions is a promising but still challenging strategy for preventing shuttling of polysulfides in lithium-sulfur batteries.Herein,ultrathin nonlayered NiO/Ni_(3)S_(2)heterostructure nanosheets are developed through topochemical transformation of layered Ni(OH)_(2)templates to improve the utilization of sulfur and facilitate stable cycling of batteries.As a multifunction catalyst,NiO/Ni_(3)S_(2)not only enhances the adsorption of polysulfides and shorten the transport path of Li ions and electrons but also promotes the Li_(2)S formation and transformation,which are verified by both in-situ Raman spectroscopy and electrochemical investigations.Thus,the cell with NiO/Ni_(3)S_(2)as electrocatalyst delivers an area capacity of 4.8 mAh cm^(-2)under the high sulfur loading(6 mg cm^(-2))and low electrolyte/sulfur ratio(4.3 pL mg^(-1)).The strategy can be extended to 2D Ni foil,demonstrating its prospects in the construction of electrodes with high gravimetric/volumetric energy densities.The designed electrocatalyst of ultrathin nonlayered heterostructure will shed light on achieving high energy density lithium-sulfur batteries.

关键词： density functional theory simulation Li-S batteries multifunction electrocatalyst NiO/Ni_(3)S_(2)heterostructures ultrathin nonlayered nanosheets

Plasmonic semiconductor nanogroove array enhanced broad spectral band millimetre and terahertz wave detection

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Light(Science & Applications) 2021年第4期10卷 600-609页

作者： Jinchao Tong Fei Suo Tianning Zhang Zhiming Huang junhao chu Dao Hua Zhang School of Electrical and Electronic Engineering Nanyang Technological UniversityNanyang Avenue639798 SingaporeSingapore State Key Laboratory of Infrared Physics Shanghai Institute of Technical

High-performance uncooled millimnetre and terahertz wave detectors are required as a building block for a wide range of applications.The state-of-the art technologies,however,are plagued by low sensitivity,narrow spectral bandwidth,and complicated architecture.Here,we report semiconductor surface plasmon enhanced high-performance broadband millimetre and terahertz wave detectors which are based on nanogroove InSb array epitaxially grown on GaAs substrate for room temperature operation.By making a nanogroove array in the grown InSb layer,strong millimetre and terahertz wave surface plasmon polaritons can be generated at the InSb-air interfaces,which results in significant improvement in detecting performance.A noise equivalent power(NEP)of 2.2× 10^(-14)WHz^(-1/2) or a detectivity(D)of 2.7× 10^(12)cmHz^(1/2) W^(-1) at 1.75 mm(0.171 THz)is achieved at room temperature.By lowering the temperature to the thermoelectric cooling available 200 K,the corresponding NEP and D'of the nanogroove device can be improved to 3.8× 10^(-15)WHz^(-1/2) and 1.6× 10^(13) cm Hz^(-1/2) w^(-1),respectively.In addition,such a single device can perform broad spectral band detection from 0.9 mm(0.330 THz)to 9.4 mm(0.032 THz).Fast responses of 3.5μs and 780 ns are achieved at room temperature and 200 K,respectively.Such high-performance millimnetre and terahertz wave photodetectors are useful for wide applications such as high capacity communications,walk-through security,biological diagnosis,spectroscopy,and remote sensing.In addition,the integration of plasmonic semiconductor nanostructures paves a way for realizing high performance and multifunctional long-wavelength optoelectrical devices.

关键词： wave spectral terahertz

First-principles study on the alkali chalcogenide secondary compounds in Cu(In,Ga)Se_2 and Cu_2ZnSn(S,Se)_4 thin film solar cells

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Journal of Energy Chemistry 2018年第4期27卷 1140-1150页

作者： Xian Zhang Dan Han Shiyou Chen chungang Duan junhao chu Key Laboratory of Polar Materials and Devices (MOE) East China Normal University Collaborative Innovation Center of Extreme Optics Shanxi University

The beneficial effect of the alkali metals such as Na and K on the Cu（In.Ga）Se2 （CIGS） and Cu2ZnSn（S,Se）4 （CZTSSe） solar cells has been extensively investigated in the past two decades, however, in most of the studies the alkali metals were treated as dopants. Several recent studies have showed that the alkali metals may not only act as dopants but also form secondary phases in the absorber layer or on the surfaces of the films. Using the first-principles calculations, we screened out the most probable secondary phases of Na and K in CIGS and CZTSSe, and studied their electronic structures and optical properties. We found that all these alkali chalcogenide compounds have larger band gaps and lower VBM levels than CIGS and CZTSSe, because the existence of strong p-d coupling in CIS and CZTS pushes the valence band maximum （VBM） level up and reduces the band-gaps, while there is no such p-d coupling in these alkali chalcogenides. This band alignment repels the photo-generated holes from the secondary phases and prevents the electron-hole recombination. Moreover, the study on the optical properties of the secondary phases showed that the absorption coefficients of these alkali chalcogenides are much lower than those of CIGS and CZTSSe in the energy range of 0-3.4eV, which means that the alkali chalcogenides may not influence the absorption of solar light. Since the alkali metal dopants can passivate the grain boundaries and increase the hole carrier concentration, and meanwhile their related secondary phases have innocuous effect on the optical absorption and band alignment, we can understand why the alkali metal dopants can improve the CIGS and CZTSSe solar cell performance.

关键词： Cu（In,Ga）Se2 and Cu2ZnSn（S,Se）4 Thin film solar cells First-principles calculations Secondary phases Alkali dopants

Room temperature preparation of highly stable cesium lead halide perovskite nanocrystals by ligand modification for white lightemitting diodes

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Nano Research 2021年第8期14卷 2770-2775页

作者： Yu Zhang Guishun Li Changkun She Shaohua Liu Fangyu Yue Chengbin Jing Ya Cheng junhao chu Engineering Research Center for Nanophotonics and Advanced Instrument of Ministry of Education Key Laboratory of Polar Materials and Devices(Ministry of Education)The Extreme Optoelectromechanics LaboratoryDepartment of MaterialsSchool of Physics and Electronic ScienceEast China Normal UniversityShanghai 200241China

The poor stability of halide perovskite nanocrystals(NCs)has severely hindered future practical application.Herein,we proposed a facile and effective ligand modification route to synthesize stable CsPbBr_(3) nanocrystals by introducing a double-terminal ligand,namely 4,4'-Azobis(4-cyanovalericacid)(CA),to replace the conventional oleic acid(OA)ligand at room temperature.The as-synthesized CsPbBr_(3)-CA not only possesses high photoluminescence quantum yield(72%)related to the reduced trap defects,but also shows significantly improved stability exposure to water,ethanol,light,and/or heat benefiting from the CA ligand anchored to NC surfaces tightly.The photoluminescence intensity of CsPbBr_(3)-CA maintains about 80%and 75%of its initial emission intensity after immersed in water or ethanol for 360 min,respectively,whereas that of the CsPbBr_(3)-OA was quenched completely within a few minutes.Moreover,an all-inorganic white light-emitting diode(LED)covered 126%National Television System Committee(NTSC)standard and 92%Rec.2020 standard was fabricated by combining the green CsPbBr_(3)-CA and commercial red-emitting K2SiF6:Mn4+(KSF)phosphors onto a blue LED chip.Thus,the presented work initiates the development of the room temperature preparation of high quality CsPbBr_(3) and shows prospect for next-generation displays.

关键词： perovskite nanocrystals ligand modification stability white light-emitting diode

Stimulated emission at 1.54 μm from erbium/oxygen-doped silicon-based light-emitting diodes

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Photonics Research 2021年第5期9卷 714-721页

作者： JIN HONG HUIMIN WEN JIAJING HE JINGQUAN LIU YAPING DAN JENS W.TOMM FANGYU YUE junhao chu chuNGANG DUAN Key Laboratory of Polar Materials and Devices Ministry of EducationEast China Normal UniversityShanghai 200241China National Key Laboratory of Science and Technology on Micro/Nano Fabrication Laboratory Department of Micro/Nano ElectronicsUniversity of Michigan-Shanghai Jiao Tong University Joint InstituteShanghai Jiao Tong UniversityShanghai 200240China Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie 12489 BerlinGermany National Laboratory for Infrared Physics Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai 200083China

Silicon-based light sources, including light-emitting diodes(LEDs) and laser diodes(LDs) for information transmission, are urgently needed for developing monolithic integrated silicon photonics. Silicon with erbium ions(Er^(3+)) doped by ion implantation is considered a promising approach, but it suffers from an extremely low quantum efficiency. Here we report an electrically pumped superlinear emission at 1.54 μm from Er/O-doped silicon planar LEDs, which are produced by applying a new deep cooling process. Stimulated emission at room temperature is realized with a low threshold current of ~6 mA(~0.8 A∕cm^(2)). Time-resolved photoluminescence and photocurrent results have revealed the complex carrier transfer dynamics by relaxing electrons from the Si conduction band to the Er^(3+) ion. This picture differs from the frequently assumed energy transfer via electron–hole pair recombination of the silicon host. Moreover, the amplified emission from the LEDs is likely due to a quasi-continuous Er/O-related donor band created by the deep cooling technique. This work paves the way for fabricating superluminescent diodes or efficient LEDs at communication wavelengths based on rare-earth-doped silicon.

关键词： diodes pumped light

A study on ionic gated MoS2 phototransistors

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Science China(Information Sciences) 2019年第12期62卷 133-140页

作者： Binmin WU Xudong WANG Hongwei TANG Tie LIN Hong SHEN Weida HU Xiangjian MENG Wenzhong BAO Jianlu WANG junhao chu School of Physical Science and Technology Shanghai Tech University State Key Laboratory of Infrared Physics Shanghai Institute of Technical PhysicsChinese Academy of Sciences University of Chinese Academy of Sciences State Key Laboratory of ASIC and System School of Microelectronics Fudan University

Molybdenum disulfide(MoS2) holds great promise in the future applications of nanoelectronics and optoelectronic devices. Exploring those interesting physical properties of MoS2using a strong electric field provided by electrolyte-gel is a robust approach. Here, we fabricate an Mo S2 phototransistor gated by electrolyte-gel which is located on a fused silica substrate. Under the modulation of electrolyte-gel, the Schottky barrier between MoS2and source/drain electrodes can be widely regulated from 11 to 179 me V. The MoS2phototransistor exhibits excellent responsivity of 2.68 × 104A/W and detectivity of 9.6 × 1010 Jones under visible incident light at negative gate voltage modulation. We attribute the optoelectronic performance enhancement to the Schottky barrier modulation of electrolyte-gel gating. It makes the device suitable for applications in high-sensitive photodetectors.

关键词： MoS2 phototransistor electrolyte-gel gating Schottky barrier electric double layer two-dimensional materials

考虑多米诺效应的化工园区应急资源调配问题研究

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安全与环境学报 2024年第5期24卷 1658-1671页

作者：楚志勇张孝春蒋君豪陈钦佩国家消防救援局天津训练总队天津300000 广东工业大学环境科学与工程学院广州510000 应急管理部天津消防研究所天津300381

在多米诺效应的影响下,化工园区的危险化学品事故具有复杂性和不可预测性,以化工园区的危险化学品固定式危险源、应急设施、应急救援车辆及应急资源为研究对象,开展了定量风险评估、应急设施选址问题及应急资源调配问题的研究,采用理论... 详细信息

在多米诺效应的影响下,化工园区的危险化学品事故具有复杂性和不可预测性,以化工园区的危险化学品固定式危险源、应急设施、应急救援车辆及应急资源为研究对象,开展了定量风险评估、应急设施选址问题及应急资源调配问题的研究,采用理论推导、仿真分析与算例应用验证相结合的方法,并优化改进了数学模型。结果表明,多米诺效应将增加该石化工业园的整体风险,在应急救援车辆路径规划中考虑区域风险分布能够有效规避危险化学品事故所造成的高风险区域,可为化工园区应急管理数字化转型、智能化升级提供理论与方法支撑。

关键词：安全工程应急资源调配应急设施选址风险评估应急救援