Preparation and characterization of room-temperature ferromagnetism GaMnN based on ion implantation

This paper reports the fabrication of GaMnN ferromagnetic semiconductor on GaN substrate by high-dose Mn ion implantation. Both the structural and optical properties for Mn+-implanted GaN material were studied by X-ray diffraction, Raman scattering and photolumi-nescence. The results reveal that the implanted manganese incorporates on Ga site and GaMnN ternary phase is formed in the substrate. The magnetic behavior has been characterized by superconducting quantum interference device. The material shows room-temperature ferromagnet-ism. The temperature-dependent magnetization indicates different mechanism for ferromagnetism in Mn+-implanted GaN.     

纳米结构的制备及单电子器件研究

建立了单电子器件的制备工艺和单电子器件的分析、测量系统,研究了有潜在应用价值的纳米结构加工技术,制备了适合光电集成的多种纳米结构,发展了常规光刻法制备单电子器件的多种技术.其中,在生命科学和信息领域有着广泛应用的“纳米电极对”引起了国内外专家的重视.发展以“纳米电极对”为基础的单电子器件及其应用是我们目前的主要研究方向.目前我们正在探索这种单电子器件在生命芯片、微电子系统集成方面的应用.     

H在Al(111)面上吸附的多重散射X_α自洽计算

利用多重散射X_α自洽场方法研究了H在Al(111)表面吸附的桥位和顶位模型。结果表明顶位吸附的结合能优于桥位。顶位吸附中H的1s电子与Al相互作用形成不同形式的σ键,本文分析了这些成键细节,并给出了顶位吸附的态密度。     

STUDY OF THE FOUR-WAVE MIXING DIFFRACTION EFFICIENCY OF LONGITUDINAL-FIELD MULTIPLE-QUANTUM-WELL PHOTOREFRACTIVE DEVICE GROWN AT LOW TEMPERATURE

We investigate the relationship between the beam intensity and the four-wave mixing diffraction efficiency of longitudinal-field multiple-quantum-well(LMQW) photorefractive device grown at low temperature. The optimum beam intensity is found. We also explain the different mechanisms of the effect of beam intensity on the diffraction efficiency of the LMQW device and the transverse-field MQW device. Some advice on how to improve the diffraction efficiency is given.     

分子束外延材料从基础研究到产业化

文章计概述了分子束外延技术和材料从实验室走向产业化的成功之路,为读者提供了一个了解高技术发展的全过程：由物理学家从理论上提出人工超晶格量子阱材料;再由器件物理学家制备出若干具有重要应用价值的器件与电路,如微波毫米波高电子迁移率晶体管及电路、量子阱激光器,从而促进了分子束外延技术的发展与完善。移动通信、移动互联肉、地面宽带无结通信、汽车防碰撞雷达、高效太阳能电池等对分子束外延材料的需求为其产业化带来     

GaAs/AlxGa1-xAs量子阱能级结构设计与光谱分析

通过理论计算对用于量子阱红外探测器的GaAs/AlxGa1-xAs量子阱能级结构进行模拟设计,将不同生长结构的量子阱材料的光响应谱和光致荧光谱(PL)与计算结果进行比较.说明量子阱生长结构与量子阱能级结构的关系.欲使量子阱红外探测器的响应峰值在8μm附近,则需量子阱结构中阱宽为47nm,垒中Al含量为029.理论计算与测试结果符合得较好. 关键词：     

采用多量子阱器件的无线光通信差拍接收方案研究

研究一种采用光折变多量子阱器件的无线光通信自差拍接收方案。与寻常相干接收方案相比,省去了中频跟踪电子系统;与量子阱器件零拍方案相比,采用中频窄带滤波器,提高了接收端机的输出信噪比。理论上研究了自差拍相干接收方案,从其物理机制出发,结合信噪比分析,探讨了影响相干接收方案的主要因素。建立了该方案的实验系统,并开展了有意义的实验研究。理论分析及实验结果表明,该方案对激光大气传输所引起的诸多不利影响皆有一定的抑制作用,因而有可能应用于卫星地面激光通信和地面无线光通信系统。     

GaAs/AlGaAs量子线的制备和光致荧光谱

利用分子束外延材料的化学选择腐蚀和再生长制备出了GaAs/AIGaAs量子线并且测量了77K的光致荧光谱.也得到透射电子显微镜的照片. 关键词：     

InGaAs/InAlAs多量子阱结构的量子限制Stark效应研究

通过吸收光电流谱的测量.观察到用国产MBE设备生长的与InP衬底晶格匹配的In-GaAs/InAlAs多量子阱结构的量子限制Stark效应及其与光偏振方向有关的各向异性电吸收特性.报道了可用于波导型调制器制作的MQW样品材料的X射线双晶衍射结果,并用计算机模拟出与实测十分相似的曲线,得到了可靠的量子阱结构参数,证明样品材料具有优良的外延质量.利用等效无限深阱模型进行的理论计算表明,应考虑样品p-i-n结内建电场的影响,才能使算出的吸收边红移与实验值符合. 关键词：     

Properties of InGaP／GaAs Grown by Solid-Source Molecular Beam Epitaxy with a GaP Decomposition Source

Lattice-matched InGaP on GaAs (001) was successfully grown by solid-source molecular beam epitaxy witha GaP decomposition source. A 0.5-μm-thick InGaP epilayer shows photoluminescence peak energy as large as 1.991eV at 15K, the full width at half maximum as small as 9.4meV and x-ray diffraction rocking curve linewidth as narrow as 25 arcsec. The electron mobilities of undoped and Si-doped InGaP layers obtained by Hall measurements are comparable to similar InGaP/GaAs heterojunction grown by solid-source molecular beamepitaxy with other sources or other growth techniques. The results reveal that the InGaP/GaAs heterojunction grown bY the present growth way have great potential applications for semiconductor devices.