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Chinese Annals of Mathematics,Series B 2003年第2期24卷 167-190页

作者： P.DEGOND ZHANGKAIJUN Mathematiquespourl‘IndustrieetlaPhysique UMRCNRS5640UniversitePaulSabatier118routedeNarbonne31062ToulousecedexFrance. DepartmentofMathematics NortheastNormalUniversityChangchun130024China.

The authors first establish a quantum microscopic scattering matrix model in multidimen-sional wave-vector space, which relates the phase space density of each superlattice cell withthat of the neighbouring cells. Then, in the limit of a large number of cells, a SHE (SphericalHarmonics Expansion)-type model of diffusion equations for the particle number density in theposition-energy space is obtained. The crucial features of diffusion constants on retaining thememory of the quantum scattering characteristics of the superlattice elementary cell (like *** resonances) are shown in order. Two examples are treated with the analyticallycomputation of the diffusion constants.

关键词： superlattices Scattering matrix model Diffusion approximation Spherical harmonics expansion Drift-diffusion Energy transport Transmission resonance

Optical transmission through basic-structural-unit superlattices

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Chinese Physics B 2010年第9期19卷 627-633页

作者：张国刚杨湘波 MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science South China Normal University

In this paper, by the transparent-component-decimation （TCD） method we obtain three kinds of new basic- components （BCs） through simplifying and decomposing the BCs of three-component Thue-Morse （3CTM） sequence. Based on these new BCs we propose a type of basic-structural-units （BSUs） and investigate the optical transmission of the one-dimensional （1D） superlattices composed of these BSUs. It is found that if the substrates of the 1D BSU superlattices are certain, the optical transmission at the central wavelength （CW） will be determined completely by the number and the type of BSUs and has nothing to do with the marshalling sequence. In particular, if the substrates are identical, the numbers of different types of BSUs are all the same and the middle two elements of BSUs constitute a cycle, then no matter whether the system is periodic, or quasiperiodic, or aperiodic, or unordered, or even random, it will be transparent at the CW. The conclusion is confirmed by the numerical results. Similar to the even layers of neighbourhood identical elements in TCD method, such a kind of optical BSU subsystem can also be decimated from the chain in the process of transmission investigation. There would be a potential application in the designing of some interesting optical devices.

关键词： optical transmission basic-structural-units superlattices

Laser molecular-beam epitaxy and second-order optical nonlinearity of BaTiO_3/SrTiO_3 superlattices

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Science China Mathematics 2000年第7期43卷 760-766页

作者：赵彤陈凡吕惠宾杨国桢陈正豪 Laboratory of Optical Physics Institute of Physics & Center for Condensed Matter Physics Chinese Academy of Sciences Beijing 100080 China

A series of c-axis oriented BaTiO3/SrTiO3 superlattices with the atomic-scale precision were epitaxially grown on single-crystal SrTiO3(100) substrates using laser molecular-beam epitaxy (LMBE). A periodic modulation of the intensity of reflection high-energy electron diffraction (RHEED) in BaTiO3 and SrTiO3 layers was observed and attributed to the lattice-misfit-induced periodic variation of the terrace density in film surface. The relationship between the second-order nonlinear optical sus-ceptibilities and the superlattice structure was systematically studied. The experimental and theoretical fitting results indicate that the second-order nonlinear optical susceptibilities of BaTiO3/SrTiO3 superlattices were greatly enhanced with the maximum value being more than one order of magnitude larger than that of bulk BaTiO3 crystal. The mechanism of the enhancement of the second-order optical non-linearity was discussed by taking into account the stress-induced lattice distortion and polarization enhancement.

关键词： BaTiO3/SrTiO3 superlattices laser molecular-beam epitaxy reflection high-energy electron diffrac-tion lattice misfit second-order optical nonlinearity.

Growth and fabrication of a mid-wavelength infrared focal plane array based on type-II InAs/GaSb superlattices

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Journal of Semiconductors 2013年第11期34卷 74-78页

作者：王国伟向伟徐应强张亮彭振宇吕衍秋司俊杰王娟邢军亮任正伟牛智川 State Key Laboratory of superlattices and Microstructures Institute of Semiconductors Chinese Academy of Sciences Luoyang Optical Electronics Development Center

We present the fabrication of a mid-wavelength infrared focal plane array （FPA） based on type-II InAs/GaSb strain layer superlattices （SLs）. The detectors contain a 400-period 8 ML InAs/8 ML GaSb SL active layer, which is grown by solid source molecular beam epitaxy on GaSb （100） N type substrates. Lattice mismatch between the superlattices and GaSb substrate achieves 148.9 ppm. The full width at half maximum of the first or- der satellite peak from X-ray diffraction was 28 arcsec. Single element detectors and FPA with a 128 x 128 pixels were fabricated using citric acid based solution wet chemical etching. Chemical and physical passivation effectively reduces the surface leakage and this process was characterized by I-V measurement. The devices showed a 50% cut-off wavelength of 4.73 μm at 77 K. The photodiode exhibited an RoA of 103 f2. cm2. The FPA was characterized with an integration time of 0.5 ms and F/2.0 optics at 77 K and the average blackbody detectivity of the detectors is 2.01 × 10^9 ***^1/2/W.

关键词： superlattices GaSb focal plane array infrared detector

Van der Waals integration of artificial heterostructures and highorder superlattices

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National Science Open 2023年第1期2卷 52-61页

作者： Qi Qian Zhong Wan Xiangfeng Duan Department of Chemistry and Biochemistry University of CaliforniaLos Angeles CA 90095USA California NanoSystems Institute University of California Los AngelesLos Angeles CA 90095USA

The recent blossom in 2D atomic crystals(2DACs)has ignited intense interest in a new type of bond-free van der Waals heterostructures(vdWHs),in which distinct material components are physically brought together within a vdW distance and held together by weak vdW *** direct chemical bonding between the constituent materials,the vdWHs negate the lattice matching requirements in typical epitaxially bonded *** we briefly summarize the key advances in the construction and fundamental investigation of versatile vdWHs from diverse 2DACs and beyond,and highlight a unique class of vdW superlattices(vdWSLs)consisting of alternating 2D atomic layers and/or self-assembled molecular layers,with tailored structural symmetry,electronic band modulation,interlayer coupling,and ***,we conclude with a brief outlook on the opportunities in exploring such artificial materials to unlock previously inaccessible physical limits and enable new device concepts beyond the reach of the existing materials.

关键词： van der Waals integration heterostructures high-order superlattices

Band structure engineering through van der Waals heterostructing superlattices of two-dimensional transition metal dichalcogenides

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InfoMat 2021年第2期3卷 201-211页

作者： Xin-Gang Zhao Zhiming Shi Xinjiang Wang Hongshuai Zou Yuhao Fu Lijun Zhang State Key Laboratory of Integrated Optoelectronics Key Laboratory of Automobile Materials of MOECollege of Materials Science and EngineeringJilin UniversityChangchunJilinChina State Key Laboratory of Luminescence and Applications Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchunJilinChina College of Physics Jilin UniversityChangchunJilinChina

The indirect-to-direct band-gap transition in transition metal dichalcogenides(TMDCs)from bulk to monolayer,accompanying with other unique properties of two-dimensional materials,has endowed them great potential in optoelectronic *** easy transferability and feasible epitaxial growth pave a promising way to further tune the optical properties by constructing van der Waals ***,we performed a systematic high-throughput first-principles study of electronic structure and optical properties of the layerby-layer stacking TMDCs heterostructing superlattices,with the configuration space of[(MX2)n(M0X02)10−n](M/M0=Cr,Mo,W;X/X0=S,Se,Te;n=0-10).Our calculations involving long-range dispersive interaction show that the indirect-to-direct band-gap transition or even semiconductor-to-metal transition can be realized by changing component compositions of *** analysis indicates that the indirect-to-direct band-gap transition can be ascribed to the in-plane strain induced by lattice *** semiconductor-to-metal transition may be attributed to the band offset among different components that is modified by the in-plane *** superlattices with direct band-gap show quite weak band-gap optical transition because of the spacial separation of the electronic states *** general,the layers stacking-order of superlattices results in a small up to 0.2 eV band gap fluctuation because of the built-in *** results provide useful guidance for engineering band structure and optical properties in TMDCs heterostructing superlattices.

关键词： heterostructures indirect-to-direct band-gap transition superlattices transition metal dichalcogenides two-dimensional materials

Interfaces in InAs/GaSb superlattices Grown by Molecular Beam Epitaxy

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Chinese Physics Letters 2009年第4期26卷 221-224页

作者：郭杰孙维国彭震宇周志强徐应强牛智川 Material School NorthWest Polyteehnical University Xi'an 710000 Luoyang Optical Electronic Center PO Box 030 Luoyang 471009 Institute of Semiconductors Chinese Academy of Sciences Beijing 100083

Short period InAs（4ML）/GaSb（SML） superlattices （SLs） with InSb- and mixed-like （or Ga1-xInxAs1-ySby- like） interfaces （IFs） are grown by molecular-beam epitaxy （MBE） on （001） GaSh substrates at optimized growth temperature. Raman scattering reveals that two kinds of IFs can be formed by controlling shutter sequences. X-ray diffraction （XRD） and atomic force microscopy （AFM） demonstrate that SLs with mixed-like IFs are more sensitive to growth temperature than that with InSb-like IFs. The photoluminescence （PL） spectra of SLs with mixed-like IFs show a stronger intensity and narrower line width than with InSb-like IFs. It is concluded that InAs/GaSb SLs with mixed-like IFs have better crystalline and optical properties.

关键词： INTERFACES (Physical sciences) superlattices MOLECULAR beam epitaxy RAMAN effect PHOTOLUMINESCENCE OPTICAL properties CRYSTAL growth

Controllable Growth of Ni Nanocrystals Embedded in BaTiO<sub>3</sub>/SrTiO<sub>3</sub>superlattices

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Modeling and Numerical Simulation of Material Science 2013年第1期3卷 4-8页

作者： Zhengwei Xiong Weidong Wu Science and Technology on Plasma Physics Laboratory Research Center of Laser Fusion China Academy of Engineering Physics Mianyan China

BaTiO3/SrTiO3 superlattices with embedded Ni nanocrystals (NCs) have been grown on SrTiO3 (001) substrate using laser molecular beam epitaxy (L-MBE). In situ reflection high-energy electron diffraction (RHEED) was employed to investigate the process of lattice strain in the self-organization of Ni NCs and the epitaxial growth of BaTiO3/SrTiO3 superlattices. The results indicated that the strain from large lattice mismatch drove the self-organization of Ni NCs. Also, the layer-by-layer growth of BaTiO3/SrTiO3 superlattices Keywords: Nanocrystal;superlattices;Self-organization 1. Introduction Oxide artificial superlattices, especially (001) oriented BaTiOsuperlattices and the island growth of Ni NCs were controllable ac-curately. The fine alternation of the two processes would provide a possible route to engineer controllably the nano-composite microstructure.

关键词： Nanocrystal superlattices Self-organization

NEW-TYPE ARTIFICIALLY FUNCTIONAL MATERIALS——METALLIC superlattices

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Progress in Natural Science:Materials International 1991年第3期 201-210页

作者：胡安蒋树声 Laboratory of Solid State Microstructures Nanjing University Nanjing 210008 PRC

Ⅰ.INTRODUCTIONThe metallic superlattices are a new type of artificial *** physical idea origi-nated from Esaki and *** periodicity of natural crystals,in some sense,dominatestheir physical *** that the original periodicity is artificially modulated by alarge periodicity which is one to two orders of magnitude larger than the original one,it is ex-pected that the new periodicity of a superlattice will change the electron and phonon struc-

关键词： functional materials superlattices high technology

Antireflection Coating at Metamaterial Waveguide Structure by Using superlattices (LANS)

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Journal of Modern Physics 2014年第8期5卷 633-642页

作者： H. M. Mousa Physics Department Al Azhar University Gaza Palestinian

The characteristics of electromagnetic wave reflection and transmission by multilayered structures consisting of a pair of left-handed material (LHM) and superlattices (LANS) slabs inserted between two semi-infinite dielectric media are investigated for photovoltaic and solar energy applications. Maxwell’s equations are used to determine the electric and magnetic fields of the perpendicular polarized wave incident at each layer. Snell’s law is applied and the boundary conditions are imposed at each layer interface to calculate the reflected and transmitted coefficients of the structure. The reflected, transmitted powers are determined using these coefficients by a recursive method. The reflected and transmitted powers are computed in both visible and microwave spectral band with the appropriate LHM for each band and appropriate location of LANS in the structure. They are illustrated as a function of the incident wavelength, angle of incidence, magnetic fraction of LANS and thickness of the slabs with the emphasis on the appropriate refractive indices. I found that, zero reflectance and maximum transmittance of the incident powers are achieved for visible spectral band at a single frequency if LHM and LANS have the same refractive index of opposite signs with the same width and more magnetic material of LANS while the reflected power is zero for less magnetic material of LANS in the microwave spectral band which realizes antireflection coating in this structure.

关键词： Angle of Incidence Magnetic Fraction Metamaterial Microwave Band Reflection Transmission superlattices Visible Band