超薄层AlGaAs样品的光调制反射谱研究

用调制光谱的方法对分子束外延（MBE）生长在GaAs（100）衬底上的一组超薄层本征型Al_xGa_1-xAs层进行了原位的研究．对厚度在35nm以下的一组样品观察到了若干个跃迁峰，而对厚度在100nm的样品只观察到了一个跃迁峰．观察到的各峰随厚度的改变而变化．用台阶势模型很好地解释了实验结果 关键词：     

量子限制受主的光致发光研究

对一系列δ掺杂浅受主铍（Be）原子的GaAs/AlAs多量子阱和均匀掺杂Be受主的GaAs体材料中Be原子的能级间跃迁进行了光致发光（PL）研究.实验中所用的样品是通过分子束外延技术生长的均匀掺杂Be受主的GaAs外延单层样品和一系列GaAs/AlAs多量子阱样品,并在每量子阱中央进行了Be原子的δ掺杂,量子阱宽度为30 到200 ?.在4.2 K温度下测量了上述系列样品的光致发光谱,清楚地观察到了束缚激子的受主从基态1s_3/2（Γ₆）到第一激发态 关键词： 量子限制受主 光致发光 多量子阱 δ掺杂     

ZnCdSe／ZnSe多量子阱的生长和激光光学性质的研究

用分子束外延在GaAs衬底上生长了ZnCdSe/ZnSe多量子阱结构,利用X射线衍射（XRD）、变温度PL光谱和ps发光衰减等研究了ZnCdSe/ZnSe多量子阱结构和激子复合特性,由变温PL光谱讨论了随温度升高辐射线宽展宽和辐射复合效率降低的机理。     

GaAIAs／GaAs非均匀阱宽多量子阱超辐射发光管材料制备及表征

超辐射发光二极管（SLD）具有不同于半导体激光器和普通发光二极管的优异性能。为了制备高功率半导体超辐射发光管，并且得到比较大的光谱宽度、大的单程增益和抑制电流饱和，我们研究设计了具有850nm辐射波长的GaAlAs／GaAs非均匀阱宽多量子阱超辐射发光二极管结构，采用分子束外延（MBE）方法进行了材料制备。同时利用X射线双晶衍射，变温（10～300K）光致发光（PL）等方法检测分析了外延薄膜的结构和光电特性。在光致发光谱线中我们得到了发射波长850nm的谱峰，谱峰范围跨跃800～880nm，双晶回摆曲线结果显示了设计的结构得到实现。在注入电流140mA时，器件输出光谱的半峰全宽可以达到26nm，室温下连续输出功率达到6mw。     

InGaAs/GaAs单量子阱PL谱的温度变化特性

采用分子束外延方法制备了InGaAs/GaAs单量子阱,利用自组装的光致荧光探测系统,对其进行了光致荧光谱研究。考察了不同温度下荧光峰波长、峰形的影响。研究结果表明:高温时荧光主要是源于带—带间载流子跃迁,而在低温时则来源于束缚在量子阱中激子的跃迁。     

InGaAsSb量子阱的MBE生长和光致发光特性研究

采用分子束外延(MBE)技术生长InGaAsSb多量子阱结构,利用光致发光光谱对材料的生长特性进行了研究.研究了衬底温度对材料激发光谱强度的影响,探索了发光波长与有源层量子阱厚度的关系.发现外延生长时衬底温度对材料的质量有重要影响;在一定范围内,量子阱厚度不断增加会导致材料的光致发光波长增加.     

InAs/GaAs柱形岛的制备及特性研究

利用固源分子束外延（MBE）的方法经SK模式自组装生长由多层InAs／GaAs量子点组成的柱形岛.具体分析了GaAs间隔层厚度，生长停顿时间以及InAs淀积量对发光峰波长的影响.原子力显微镜（AFM）结果显示柱形岛表面的形状和尺寸都比较均匀；室温下不同高度的柱形岛样品的发光波长分别达到1.32和1.4μm，而单层量子点的发光波长仅为1.1μm，充分说明了量子点高度对发光波长的决定性影响，这为调节量子点发光波长提供了一种直观且行之有效的方法. 关键词： 柱形岛 生长停顿 间隔层厚度 PL谱     

快速热退火引起GaAs/AlGaAs双量子阱中铝原子的扩散研究

用分子束外延生长了GaAs/AlGaAs双量子阱激光器结构样品，并对不同温度快速热退火导致量子阱组分无序即阱和垒中三族元素的扩散过程进行了实验和理论研究.用光荧光技术测量退火样品的n=1量子阱能级跃迁峰值位置，结果表明退火前后样品量子阱能级位置发生蓝移，蓝移量随温度的提高而增大.对退火过程中GaAs/AlGaAs量子阱中三族元素的扩散过程进行了理论分析，并与实验结果相比较，获得了不同退火温度下铝原子的扩散系数和扩散过程的激活能.950℃，30s退火条件下，铝原子的扩散系数为6.6×10^{-16相似文献}   

分子束外延生长的(GaAs1－xSbx/InyGa1－yAs)/GaAs量子阱光致发光谱研究

报道了(GaAs_1-xSb_x/In_yGa_1-yAs)/Ga As量子阱结构的分子束外延生长与光致发光谱研究结果.变温与变激发功率光致发光谱的研究表明了此结构 为二型量子阱发光性质.讨论了光谱双峰结构的跃迁机制.通过优化生长条件，获得了室温1 31μm发光. 关键词： 分子束外延 量子阱 二型发光     

压电调制反射光谱研究GaAs/Al0.29Ga0.71As单量子阱

报道了压电调制反射测量系统的建立，应用该系统获得了势阱宽度分别为5nm和25nm的两个G aAs/Al_0.29Ga_0.71As单量子阱的压电调制反射谱. 从图谱中可以看 出，在室 温下能够较容易地分辨出和轻、重空穴相关联的子带跃迁. 在阱宽25nm的样品中还观察到了 自旋-轨道跃迁. 利用有效质量理论近似计算，对量子阱样品的图谱结构进行了指认，发现 实验值和计算值能够较好地符合. 关键词： 压电调制反射光谱 单量子阱 分子束外延     

稳定的GaAs (2 5 1 1)高密勒指数表面的电子结构

采用格林函数方法对具有稳定结构的GaAs(2 5 11)(1×1)表面的电子结构特性进行了计算. 结果表明：对于理想的GaAs(2 5 11)表面，基本带隙内的表面态主要处在三个能量区域，即 -0.1—0.1eV，085—10eV和1.4—1.6eV之间；吸附两个As原子形成(1×1)再构后，表面态的变化主要表现在0.85—1.0eV之间的表面态完全消失.结合电子数目规则，可以确定处在 - 0.1—0.1eV之间的表面态为全部填满的阴离子悬挂键态或再构引起的As As二聚体键的表 面态，而处在1.4— 关键词： 高密勒指数表面 电子结构 电子数目规则     

Structural and optical properties of high-density (>10/cm) InAs QDs with varying Al(Ga)As matrix layer thickness

We have obtained high-density (>10¹¹/cm²) InAs quantum dot (QD) structures by using an Al(Ga)As matrix layer. With increase of the AlAs matrix layer thickness, the density of QDs increases a little and the luminescence intensity emitted from InAs QDs decreases. We have used a thin GaAs insertion layer (IL) for the reason of keeping InAs QDs from an aluminum intermixing towards QDs. As the thickness of GaAs IL increases, the density of QDs decreases slightly due to the reduction of the roughness of an AlAs matrix layer. However, the luminescence intensity increases with increase in the thickness of GaAs IL resulting from the efficient blocking of an aluminum intermixing towards QDs.     

Optical and electronic properties of single modulation doped GaAs/AlGaAs V-grooved quantum wire modified by ion implantation

1 Introduction Recently, there is considerable interest in the fabrication and study of quasi-one di-mensional quantum wires (QWRs) due to their potential application for novel optoelec-tronic devices such as QWR laser array [1,2] etc. Among the various techniques devel-oped for producing quasi-one dimensional (quasi-1D) QWRs, the self-organized growth on patterned substrates has been proven to be one of the most promising methods, due to the simplicity of fabrication[3―5]. The QWR is fa…     

Alloy formation at the Ni–Al interface for nickel films deposited on Al(110) surfaces

Alloy formation at the Ni–Al interface for thin nickel films deposited on Al(110) surfaces has been studied using high-energy ion scattering/channeling (HEIS) and X-ray photoelectron spectroscopy (XPS). For nickel atoms deposited at room temperature on Al(110), a large amount of nickel–aluminum intermixing occurs at the interface. For the first two monolayers (ML) of deposited nickel, an NiAl-like compound is formed. The intermixing continues with a different rate, forming an Ni₃Al-like compound for nickel coverages from 2 to 8 ML, at which point a nickel metal film begins to grow on the surface. Nickel atoms deposited at 250°C on the Al(110) surface exhibit no surface compound formation, but diffuse up to 400 Å into the aluminum substrate. Interatomic potentials based on the embedded-atom method (EAM) are used in a Monte Carlo approach to simulate the evolution of the Ni–Al(110) interface as a function of the nickel coverage. The calculated ion-scattering yields and X-ray photoelectron intensities from nickel and aluminum atoms in these simulated interfaces are in good quantitative agreement with the experimental results. The simulations show a high-density Ni–Al alloy forming at the Al(110) surface which apparently inhibits outward diffusion of aluminum, leading to the more nickel-rich alloy and finally nickel film growth. The ion-scattering simulations show an unusually large amount of backscattering occurring below the Ni–Al(110) interface, apparently associated with defocusing of the incident ion beam.     

InGaAs(P)/InP MQW mixing by Zn diffusion,Ge and S implantation for optoelectronic applications

There is a growing interest in impurity-induced layer disordering for the technologically important InGaAs(P)/InP system. More complicated than in the AlGaAs/GaAs ternary system, which concerns only interdiffusion of group III atoms, interdiffusion in this quaternary system can occur for both group III (Ga,In) and group V (P,As) atoms, which may or may not result in a strain-free alloy lattice-matched to InP, a major concern for device applications. After a brief review on the thermal stability of InP/ InGaAs quantum well structures, we show that Zn diffusion at moderate temperature leads to intermixing on the group III sublattice, only, with subsequent lattice mismatch. On the other hand, either Ge or S implantation of InGaAs/InP quantum wells results in intermixing involving both the group III and the group V sublattice and approximating the lattice-matched condition.     

红光InAlAs量子点的结构和光学性质

利用ＭＢＥ方法在（００１）衬底上成功地生长密度大、尺寸小、发红光的ＩｎＡｌＡｓ／ＡｌＧａＡｓ量子点结构。通过原子力显微镜观察表明,ＩｎＡｌＡｓ量子的密度和大小都随覆盖厚度的增加而增大;发现Ａｌ原子的表面迁移率决定ＩｎＡｌＡｓ量子点的形貌,光荧光谱证实了量子点的发光峰值在红光范围,并结合形貌的统计得到了量子点的发光峰展宽主要昌受量子点的横向尺寸影响。     

Sb/As intermixing in self-assembled GaSb/GaAs type II quantum dot systems and control of their photoluminescence spectra

The intermixing of Sb and As atoms induced by rapid thermal annealing (RTA) was investigated for type II GaSb/GaAs self-assembled quantum dots (QD) formed by molecular beam epitaxy growth. Just as in InAs/GaAs QD systems, the intermixing induces a remarkable blueshift of the photoluminescence (PL) peak of QDs and reduces the inhomogeneous broadening of PL peaks for both QD ensemble and wetting layer (WL) as consequences of the weakening of quantum confinement. Contrary to InAs/GaAs QDs systems, however, the intermixing has led to a pronounced exponential increase in PL intensity for GaSb QDs with annealing temperature up to 875 °C. By analyzing the temperature dependence of PL for QDs annealed at 700, 750 and 800 °C, activation energies of PL quenching from QDs at high temperatures are 176.4, 146 and 73.9 meV. The decrease of QD activation energy with annealing temperatures indicates the reduction of hole localization energy in type II QDs due to the Sb/As intermixing. The activation energy for the WL PL was found to drastically decrease when annealed at 800 °C where the QD PL intensity surpassed WL.     

Photoemission study of the interaction of Al with a GaAs (110) surface

A room-temperature reaction between Al adsorbate atoms and a GaAs (110) surface is observed by means of soft X-ray photoemission techniques. Evidence of two states of Al which are distinct from the bulk Al metal is seen at submonolayer coverages. The sequential appearance of these states suggest that both Al chemisorbed on the surface and Al replacing Ga in the surface lattice are present. The possible influence of surface lattice reconstruction and Al proximity effects on the replacement reaction is discussed. The replacement reaction is important in the context of metal contacts to GaAs (both ohmic and Schottky barriers) as well as for GaAs—AlGaAs heterojunctions.     

Si杂质扩散诱导InGaAs/AlGaAs量子阱混杂的研究（英文）

光学灾变损伤(COD)常发生于量子阱半导体激光器的前腔面处,极大地影响了激光器的出光功率及寿命。通过杂质诱导量子阱混杂技术使腔面区波长蓝移来制备非吸收窗口是抑制腔面COD的有效手段,也是一种高效率、低成本方法。本文选择了Si杂质作为量子阱混杂的诱导源,使用金属有机化学气相沉积设备生长了InGaAs/AlGaAs量子阱半导体激光器外延结构、Si杂质扩散层及Si 3 N 4保护层。热退火处理后,Si杂质扩散诱导量子阱区和垒区材料互扩散,量子阱禁带变宽,输出波长发生蓝移。退火会影响外延片的表面形貌,而表面形貌则可能会影响后续封装工艺中电极的制备。结合光学显微镜及光致发光谱的测试结果,得到825℃/2 h退火条件下约93 nm的最大波长蓝移量,也证明退火对表面形貌的改变,不会影响波长蓝移效果及后续电极工艺。     

组合注入质子导致不对称耦合双量子阱截面混合效应研究

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