检索结果-南通市图书馆

High-efficiency reflection phase tunable metasurface at near-infrared frequencies

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第5期30卷 650-654页

作者： Ce Li Wei Zhu Shuo Du Junjie Li changzhi gu Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences CAS Key Laboratory of Vacuum PhysicsUniversity of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Space Applied Physics and Chemistry Ministry of Education and Department of Applied PhysicsSchool of ScienceNorthwestern Polytechnical UniversityXi'an 710129China Songshan Lake Materials Laboratory Dongguan 523808China Collaborative Innovation Center of Quantum Matter Beijing 100871China

The realization of active modulation of reflection phase based on metasurfaces is of great significance for flexible control of electromagnetic wavefront,which makes metasurfaces have practical application values in polarization conversion,beam steering,metalens,*** this paper,a reflection phase tunable gap-surface plasmon(GSP)metasurface based on phase change materials Ge_(2)Sb_(2)Te_(5)(GST)is designed and experimentally *** virtue of the characteristics of large permittivities difference before and after GST phase transition and the existence of stable intermediate states,the continuous modulation of near-infrared reflection phase larger than 200°has been *** the same time,through the reasonable design of the structure sizes,the reflection has been maintained at about 0.4 and basically does not change with the GST phase transition,which improved the working efficiency of the metasurface *** addition,the coupled-mode theory(CMT)is introduced to make a full analysis of the modulation mechanism of the reflection phase,which proves that the phase transition of GST can induce the transition of metasurface working state from overcoupling mode to critical coupling *** improvement of the metasurface working efficiency has practical values for wavefront modulation.

关键词： active metasurface phase change materials phase modulation

The concept and realization of nanostructure fabrication using free-standing metallic wires with rapid thermal annealing

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2015年第4期58卷 84-90页

作者： CUI AJuan HAO TingTing LI Wu Xia SHEN TieHan LIU Zhe JIANG QianQing gu changzhi Beijing National Laboratory of Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Joule Physics Laboratory School of CSE College of Science and Technology University of Salford Collaborative Innovation Center of Quantum Matter

Free-standing metallic nanostructures are considered to be highly relevant to many branches of science and technology with applications of three dimensional metallic nanostructures ranging from optical reflectors,actuators,and antenna,to free-standing electrodes,mechanical,optical,and electrical resonators and ***-induced out-of-plane fabrication has emerged as an effective method which uses relaxation of strain-mismatched *** this work,we report a study of the thermal annealing-induced shape modification of free-standing nanostructures,which was achieved by introducing compositional or microstructural nonuniformity to the *** particular gradient,segmented and striped hetero-nanowires were grown by focused-ion-beam-induced chemical vapor deposition,followed by rapid thermal annealing in a N2 *** free-standing nanostructures were produced as a result of the crystalline/grain growth and stress relief.

关键词： thermal annealing strain.induced deformation free-standing three-dimensional nanofabrication

Field emission study of CNTs on metal tips

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2008年第1期53卷 17-21页

作者： guO DaBo YUAN guang SONG CuiHua gu changzhi WANG Qiang Deparlment of Physics Ocean University of China Qingdao 266100 China State Key Laboratory of Surface Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China

The field emission characteristics of multiwalled carbon nanotubes grown on metal tips are studied at various temperatures. It is found that emission current at a given applied electric field increased with the temperature, and the stability of the current did not change. The dependence upon temperature varies quite differently with the metal substrates. This may result from the asymmetry of the CNTs and the interface effect between CNT and underlay.

关键词：场发射碳纳米管温度特性电场

Fabrication technique of micro/nano-scale speckle patterns with focused ion beam

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2012年第6期55卷 1037-1044页

作者： LI YanJie XIE HuiMin LUO Qiang gu changzhi HU ZhenXing CHEN PengWan ZHANG QingMing AML Department of Engineering MechanicsTsinghua UniversityBeijing 100084China Institute of Physics Chinese Academy of SciencesBeijing 100190China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

The fabrication technique of micro/nano-scale speckle patterns with focused ion beam (FIB) system is studied for digital image correlation (DIC) measurement under a scanning electron microscope (SEM).The speckle patterns are fabricated by directly etching the counterpart of the specimen to the black part of a *** intensity gradient is used to evaluate the quality of these SEM images of speckle patterns fabricated based on different templates to select an optimum *** pattern size depending on the displacement measurement sensitivity is adjusted by altering the magnification of FIB according to the relation curve of the etching size versus *** influencing factors including etching time and ion beam current are *** body translation tests and rotation tests are carried out under SEM to verify the reliability of the fabricated speckle *** calculated values are in good agreement with the imposed ones.

关键词： speckle pattern digital image correlation (DIC) micro/nano-scale focused ion beam (FIB) scanning electron microscope (SEM)

A kind of double-sided porous anodic alumina membrane fabricated with the three-step anodic oxidation method

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2014年第2期57卷 293-297页

作者： ZHANG Chen WANG KaiGe GAO ZeYang WU JunJun REN JunYing ZHANG LiangLiang gu changzhi BAI JinTao Institute of Photonics & Photo-Technology Northwest University State Key Laboratory for Manufacturing Systems Engineering Xi'an Jiaotong University Institute of Physics Chinese Academy of Sciences

The porous anodic alumina membranes （PAAMs） have been successfully used as templates for the fabrication of functional nano-materials due to their outstanding regularity and physicochemical properties. In this paper, a transparent double-sided anodic alumina membrane with ultra-thin aluminum substrate was fabricated with the three-step anodic oxidation method in the oxalic acid electrolyte. The characters such as the top-surface morphology, membrane thickness, and depth of nanopores of this three-layer （A1203-A1-A1203） sandwiched nano-structure were controllable through regulating the main anodic oxidation conditions, e.g., anodic oxidation time of various steps, coating remove process. The experiments data revealed that the aluminum substrate is exponential declined with the oxidation time when it was approximately reduced by a few micrometers. This new double-sided anodic alumina membrane can be used as the high-quality functional field emission materials and templates.

关键词： double-sided porous anodic aluminum membrane three-step anodic oxidation method controllability anodic oxidation rate

Direct bandgap engineering with local biaxial strain in few-layer MoS2 bubbles

在线全文

学校读者我要写书评

暂无评论

Nano Research 2020年第8期13卷 2072-2078页

作者： Yang guo Bin Li Yuan Huang Shuo Du Chi Sun Hailan Luo Baoli Liu Xingjiang Zhou Jinlong Yang Junjie Li changzhi gu Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing100190China School of Physical Sciences CAS Key Laboratory of Vacuum PhysicsUniversity of Chinese Academy of SciencesBeijing100190China Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information&Quantum Physics(CAS) University of Science and Technology of ChinaHefei230026China Songshan Lake Materials Laboratory Dongguan523808China

Nano Research volume 13,pages2072–2078(2020)Cite this article 211 Accesses Metrics details Abstract Strain engineering provides an important strategy to modulate the optical and electrical properties of semiconductors for improving devices performance with mechanical force or thermal expansion ***,we present the investigation of the local strain distribution over few-layer MoS2 bubbles,by using scanning photoluminescence and Raman *** observe the obvious direct bandgap emissions with strain in the few-layer MoS2 bubble and the strain-induced continuous energy shifts of both resonant excitons and vibrational modes from the edge of the MoS2 bubble to the center(10μm scale),associated with the oscillations resulted from the optical interference-induced temperature *** understand these results,we perform ab initio simulations to calculate the electronic and vibrational properties of few-layer MoS2 with biaxial tensile strain,based on density functional theory,finding good agreement with the experimental *** study suggests that local strain offers a convenient way to continuously tune the physical properties of a few-layer transition metal dichalcogenides(TMDs)semiconductor,and opens up new possibilities for band engineering within the 2D plane.

关键词： two-dimensional(2D)layered materials transition metal dichalcogenides band engineering local strain

Dynamic observation of oxygen vacancies in hafnia layer by in situ transmission electron microscopy

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 2015年第11期8卷 3571-3579页

作者： Chao Li Yuan Yao Xi Shen Yanguo Wang Junjie Li changzhi gu Richeng Yu Qi Liu Ming Liu Beijing National Laboratory of Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China Laboratory of Nano-Fabfication and Novel Devices Integrated Technology Institute of Microelectronics Chinese Academy of Sciences Beijing 100029 China

The charge-trapping process, with HfO2 film as the charge-capturing layer, has been investigated by using in situ electron energy-loss spectroscopy and in situ energy-filter image under positive external bias. The results show that oxygen vacancies are non-uniformly distributed throughout the HfO2 trapping layer during the programming process. The distribution of the oxygen vacancies is not the same as that of the reported locations of the trapped electrons, implying that the trapping process is more complex. These bias-induced oxygen defects may affect the device performance characteristics such as the device lifetime. This phenomenon should be considered in the models of trapping processes.

关键词： charge-trapping flash in situ TEM electric field oxygen vacancy

Gap-surface-plasmon induced polarization photoresponse for MoS_(2)-based photodetector

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 2023年第7期16卷 10272-10278页

作者： Qinghu Bai Xin Huang Yang guo Shuo Du Chi Sun Leyong Hu Ruixuan Zheng Yang Yang Aizi Jin Junjie Li changzhi gu Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences CAS Key Laboratory of Vacuum PhysicsUniversity of Chinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China

Polarization-sensitive photodetectors based on two-dimensional(2D)materials have shown more attractive application prospects compared to traditional thin-film photodetectors due to their atomic thickness,tunable bandgap,high mobility and strong light-matter *** them,2D molybdenum disulfide(MoS_(2))has drawn numerous attentions in photodetection due to its wide spectral range,remarkable photoresponsivity and fast photo-switching ***,the isotropic crystal structure of MoS_(2)hampers its application in the polarization-sensitive detection,which is highly desired in military and civilian *** this paper,we demonstrated an integration of plasmonic nanocavity with monolayer MoS_(2)to achieve high photoresponsivity and polarization-sensitive *** the significant enhancement of electromagnetic field provided by the gap-surfaceplasmon(GSP),we achieved a significant photoluminescence(PL)enhancement of *** on the enhanced light absorption by our plasmonic nanocavity,which generally facilitates photo-generation of electron-hole pairs in MoS_(2),we achieved a high photoresponsivity of 1.88 A/W and degree of linear polarization(DOLP)of 0.8 at the excitation wavelength of 633 *** work provides a feasible and universal solution to realize polarization-sensitive photodetector of MoS_(2)for high-performance and polarization-sensitive photodetectors.

关键词： gap-surface-plasmon nanocavity MoS_(2) photodetector linear polarization

A VHF band HTS filter based on modified single-spiral resonators for radio astronomy application

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

Science China(Physics,Mechanics & Astronomy) 2013年第5期56卷 910-915页

作者： LI Chao SUN Liang WANG Jia BIAN YongBo YU Tao LI Fei LI Chunguang LI Hong gu changzhi HE YuSheng Institute of Physics Chinese Academy of Sciences

A 10-pole quasi-elliptic bandpass filter （BPF） with a relatively wide passband in the very high frequency （VHF） band was de- signed and fabricated using YBCO thin films deposited on both sides of a LaAIO3 substrate. Single-spiral resonators were modified to generate strong coupling and reduce the parasitic coupling, We analysed the coupling polarities between the modi- fied resonators. Two pairs of attenuation poles were introduced in the filter for sharp cut-off response. The measurements showed that the filter has a centre frequency of 255.8 MHz, fractional bandwidth of about 12.3%, insertion loss of smaller than 0.265 dB, and the return loss in the passband of better than 17.5 dB, in zood a^reement with computer simulations.

关键词： HTS filter spiral resonator fractional bandwidth coupling polarity parasitic coupling