检索结果-南通市图书馆

Electrical characterization of an individual nanowire using flexible nanoprobes fabricated by atomic force microscopy-based manipulation

在线全文

学校读者我要写书评

暂无评论

Nanotechnology and Precision Engineering 2023年第4期6卷 55-65页

作者： Yilin Wang enxiu wu Jirui Liu Mengke Jia Rui Zhang Sen wu State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China

Nanowires have emerged as promising one-dimensional materials with which to construct various nanocircuits and nanosensors.However,measuring the electrical properties of individual nanowires directly remains challenging because of their small size,thereby hindering the comprehensive understanding of nanowire-based device performance.A crucial factor in achieving reliable electrical characterization is establishing well-determined contact conditions between the nanowire sample and the electrodes,which becomes particularly difficult for soft nanowires.Introduced here is a novel technique for measuring the conductivity of an individual nanowire with the aid of automated nanomanipulation using an atomic force microscope.In this method,two nanowire segments cut from the same silver nanowire are positioned onto a pair of gold electrodes,serving as flexible nanoprobes to establish controllable contact with the sample.By changing the contact points along the nanowire sample,conductivity measurements can be performed on different regions,thereby eliminating the influence of contact resistance by analyzing multiple current–voltage curves.Using this approach,the resistivity of a 100-nm-diameter silver nanowire is determined to be 3.49×10^(−8)Ωm.

关键词： Electrical characterization Nanowire Flexible nanoprobe Nanomanipulation AFM

Flash memory based on MoTe_(2)/boron nitride/graphene semifloating gate heterostructure with non-volatile and dynamically tunable polarity

在线全文

学校读者我要写书评

暂无评论

Nano Research 2022年第7期15卷 6507-6514页

作者： Shijie Wang Guangyu Geng Yang Sun Sen wu Xiaodong Hu enxiu wu Jing Liu School of Precision Instruments and Opto-electronics Engineering Tianjin UniversityTianjin 300072China State Key Laboratory of Precision Measurement Technology and Instruments Tianjin 300072China

Atomically thin two-dimensional(2D)materials are promising candidates to develop flash memories with premium performances as compared to conventional bulk materials,because of their ultra-thin thickness and highly tunable electrical properties.So far,most of the reported 2D material based flash memories work in the uni-polar mode,which usually further integrate additional local gate to achieve bi-polar function.However,such approach is volatile,meaning that the gate bias has to be applied persistently to maintain the polarity change and thus increases the power consumption.Here,we report a bi-polar memory based on MoTe_(2)/h-BN/graphene semi-floating gate(SFG)heterostructure,which has non-volatile and dynamically tunable polarity.The SFG configuration has the channel layer of MoTe_(2) and dielectric layer of h-BN half-stacked on the floating gate layer of graphene.The off-graphene half of the MoTe_(2) channel can be tuned between n-type and p-type by simultaneously applying ultraviolet(UV)illumination and electrical field through the back gate,which maintains this polarity after the removal of both stimuli.As a result,the SFG memory can work in the non-volatile bi-polar mode,with a on/off ratio of~100 and switching speed of 1 ms.On the other hand,the on-graphene half of the MoTe_(2) channel remains n-type under UV illumination and electrical bias,so that the MoTe_(2) full floating gate memory maintains n-type,which implements the integration of both n-and p-type memories in a single 2D heterostructure.This capability provides great flexibility for memory devices adapting in various emerging applications.

关键词： polarity modulation ultraviolet light semi-floating gate nonvolatile

Non-volatile programmable homogeneous lateral MoTe2 junction for multi-bit flash memory and high-performance optoelectronics

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2020年第12期13卷 3445-3451页

作者： enxiu wu Yuan Xie Shijie Wang Daihua Zhang Xiaodong Hu Jing Liu State Key Laboratory of Precision Measurement Technology and Instruments School of Precision Instruments and Opto-electronics EngineeringTianjin UniversityNo.92 Weijin RoadTianjin300072China

Flash memories and semiconductor p-n junctions are two elementary but incompatible building blocks of most electronic and optoelectronic devices.The pressing demand to efficiently transfer massive data between memories and logic circuits,as well as for high data storage capability and device integration density,has fueled the rapid growth of technique and material innovations.Two-dimensional(2D)materials are considered as one of the most promising candidates to solve this challenge.However,a key aspect for 2D materials to build functional devices requires effective and accurate control of the carrier polarity,concentration and spatial distribution in the atomically thin structures.Here,a non-volatile opto-electrical doping approach is demonstrated,which enables reversibly writing spatially resolved doping patterns in the MoTe2 conductance channel through a MoTe2/hexagonal boron nitride(h-BN)heterostructure.Based on the doping effect induced by the combination of electrostatic modulation and ultraviolet light illumination,a 3-bit flash memory and various homojunctions on the same MoTe2/BN heterostructure are successfully developed.The flash memory achieved 8 well distinguished memory states with a maximum on/off ratio over 10^4.Each state showed negligible decay during the retention time of 2,400 s.The heterostructure also allowed the formation of p-p,n-n,p-n,and n-p homojunctions and the free transition among these states.The MoTe2 p-n homojunction with a rectification ratio of 10^3 exhibited excellent photodetection and photovoltaic performance.Having the memory device and p-n junction built on the same structure makes it possible to bring memory and computational circuit on the same chip,one step further to realize near-memory computing.

关键词： 3-bit flash memory p-n homojunctions MoTe2 opto-electrical doping near-memory computing photovoltaic

Epitaxial graphene gas sensors on SiC substrate with high sensitivity

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Semiconductors 2020年第3期41卷 2-6页

作者： Cui Yu Qingbin Liu Zezhao He Xuedong Gao enxiu wu Jianchao Guo Chuangjie Zhou Zhihong Feng National Key Laboratory of ASIC Hebei Semiconductor Research InstituteShijiazhuang 050051China College of Precision Instrument and Opto-electronics Engineering Tianjin UniversityTianjin 300072China

2D material of graphene has inspired huge interest in fabricating of solid state gas sensors.In this work,epitaxial graphene,quasi-free-standing graphene,and CVD epitaxial graphene samples on SiC substrates are used to fabricate gas sensors.Defects are introduced into graphene using SF6 plasma treatment to improve the performance of the gas sensors.The epitaxial graphene shows high sensitivity to NO2 with response of 105.1%to 4 ppm NO2 and detection limit of 1 ppb.The higher sensitivity of epitaxial graphene compared to quasi-free-standing graphene,and CVD epitaxial graphene was found to be related to the different doping types of the samples.

关键词： graphene high limit

在线全文

学校读者我要写书评

暂无评论

原子层制造的研究现状与科学挑战

中国科学基金 2024年第1期38卷 99-114页

作者：钱林茂陈蓉朱利民赵德文彭小强周平邓辉余家欣曹坤杜春阳武恩秀江亮石鹏飞陈磊西南交通大学机械工程学院华中科技大学机械科学与工程学院上海交通大学机械与动力工程学院清华大学机械工程系国防科技大学人工智能学院大连理工大学机械工程学院南方科技大学机械与能源工程系西南科技大学制造过程测试技术教育部重点实验室天津大学精密测试技术及仪器全国重点实验室

原子层制造是指加工精度达到原子层量级的可控制造技术，包括原子层去除、添加、迁移等。针对信息、能源、航空航天等领域核心零部件超高性能构建的发展需求，通过原子层可控去除制造全频段原子级精度无损表面，并结合原子层增材制造原... 详细信息

原子层制造是指加工精度达到原子层量级的可控制造技术，包括原子层去除、添加、迁移等。针对信息、能源、航空航天等领域核心零部件超高性能构建的发展需求，通过原子层可控去除制造全频段原子级精度无损表面，并结合原子层增材制造原子级新结构，有望实现特殊功能的有效创成，保证超高性能的安全可靠。另外，后摩尔时代先进芯片的制造工艺将迈入亚纳米物理极限，原子层制造需求贯穿芯片制造工艺的全流程。本文阐述了原子层制造技术的发展需求与研究进展，围绕原子层抛光、原子层沉积/刻蚀、原子层损伤控制、原子层工艺与装备等领域，梳理了原子层制造的发展方向及研究目标，凝练了原子层制造领域未来的关键科学问题及面临的挑战，探讨了前沿研究方向和发展战略。

关键词：原子层制造原子层抛光原子层沉积/刻蚀原子层损伤控制原子层制造工艺与装备

低氧胁迫对鲢心肌细胞凋亡及其调控基因Bax、Bcl-2表达的影响

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

淡水渔业 2018年第2期48卷 10-15页

作者：丁晨雨胡利双李云薛洋李虹吴荣华刘恩秀李晓洁西南大学动物科技学院重庆三峡生态渔业产业技术研究院重庆400715 西南大学淡水鱼类资源与生殖发育教育部重点实验室重庆400715 重庆市水产技术推广总站重庆400200

为了解低氧胁迫对鲢心脏的损伤及其机制,检测了不同低氧条件下鲢血清肌酸激酶(CK)活力和心肌细胞凋亡情况及凋亡调控基因Bax、Bcl-2的表达。结果显示:低氧胁迫下血清CK活性显著升高,表明低氧实验中鲢心肌细胞可能受到了损伤;TUNEL检测... 详细信息

为了解低氧胁迫对鲢心脏的损伤及其机制,检测了不同低氧条件下鲢血清肌酸激酶(CK)活力和心肌细胞凋亡情况及凋亡调控基因Bax、Bcl-2的表达。结果显示:低氧胁迫下血清CK活性显著升高,表明低氧实验中鲢心肌细胞可能受到了损伤;TUNEL检测显示低氧胁迫鲢心肌细胞发生了凋亡,且随着氧浓度的下降凋亡指数升高,组间差异极显著;qPCR显示,鲢心肌Bax基因和Bcl-2基因变化趋势相反,Bax基因随着处理时间的延长,氧浓度的下降,表达量升高,Bcl-2基因表达量降低,且实验结束时与常氧对照值(Normoxia group,NO)比较差异显著。结果表明,低氧胁迫通过升高鲢心肌Bax基因表达、降低Bcl-2基因表达,导致心肌细胞凋亡,从而造成鲢心脏损伤甚至鱼死亡。

关键词：低氧胁迫鲢(Hypophthalmichthys molitrix) 心肌细胞细胞凋亡 Bcl2 Bax

Anisotropic photoresponse of layered rhenium disulfide synaptic transistors

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第8期30卷 49-54页

作者：安春华徐志昊张璟武恩秀马新莉庞奕荻付晓胡晓东孙栋苗金水刘晶 State Key Laboratory of Precision Measurement Technology and Instruments School of Precision Instruments and Opto-electronics EngineeringTianjin UniversityTianjin 300072China State Key Laboratory of Infrared Physics Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai 200083China International Center for Quantum Materials School of PhysicsPeking UniversityBeijing 100871China

Layered ReS_(2) with direct bandgap and strong in-plane anisotropy shows great potential to develop high-performance angle-resolved photodetectors and optoelectronic devices.However,systematic characterizations of the angle-dependent photoresponse of ReS_(2) are still very limited.Here,we studied the anisotropic photoresponse of layered ReS_(2) phototransistors in depth.Angel-resolved Raman spectrum and field-effect mobility are tested to confirm the inconsistency between its electrical and optical anisotropies,which are along 120°and 90°,respectively.We further measured the angle-resolved photoresponse of a ReS_(2) transistor with 6 diagonally paired electrodes.The maximum photoresponsivity exceeds 0.515 A·W^(-1) along b-axis,which is around 3.8 times larger than that along the direction perpendicular to b axis,which is consistent with the optical anisotropic directions.The incident wavelength-and power-dependent photoresponse measurement along two anisotropic axes further demonstrates that b axis has stronger light-ReS_(2) interaction,which explains the anisotropic photoresponse.We also observed angle-dependent photoresistive switching behavior of the ReS_(2) transistor,which leads to the formation of angle-resolved phototransistor memory.It has simplified structure to create dynamic optoelectronic resistive random access memory controlled spatially through polarized light.This capability has great potential for real-time pattern recognition and photoconfiguration of artificial neural networks(ANN)in a wide spectral range of sensitivity provided by polarized light.

关键词： ReS2 in-plane anisotropy anisotropic photoresponse phototransistor