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1.
We present electronic transport in n- and p-type modulation-doped GaInNAs/GaAs quantum well structures. The Hall mobility of electrons in the n-type material decreases dramatically with increasing nitrogen composition. The mobility of 2D holes in p-modulation-doped quantum wells is significantly higher than that of 2D electrons in n-modulation-doped material with similar nitrogen concentration. The mobility of 2D electrons is discussed using a S-matrix model for N-related alloy scattering. The results indicate that the electron mobility is intrinsically limited by scattering from nitrogen complexes. The high mobility of 2D holes is explained in terms of negligible effect of nitrogen on valance band and the absence of scattering with localized nitrogen complexes. 相似文献
2.
In this paper, we study the effect of the incorporation of nitrogen in strained GaInAs quantum well structures. We evaluate the influence of nitrogen on the conduction band energy by using the band anticrossing model. The incorporation of nitrogen appears to decrease the bandgap energy and increase the emission wavelength. The reduction of energy is due to the interaction of the energy of the conduction band with the level of nitrogen and more the concentration of nitrogen increases, more the energy of the band gap decreases. On the other hand, the emission wavelength increases, the advantage of the incorporation of nitrogen in such structures is to vary the wavelength between 0.980 and 1.3 μm while exploiting of course the composition of gallium, composition of nitrogen and the thickness of the quantum well. Less temperature insensitive devices are so intended to be fabricated. 相似文献
3.
I. K. Shmagin J. F. Muth R. M. Kolbas S. Krishnankutty S. Keller A. C. Abare L. A. Coldren U. K. Mishra S. P. Den Baars 《Journal of Electronic Materials》1997,26(3):325-329
Photoluminescence (PL) characteristics of GaN/lnGaN/GaN single quantum wells (QWs) and an InGaN/GaN single heterojunction were studied using continuous wave (CW) and pulsed photoluminescence in both edge and surface emitting configurations. Samples were grown on c-plane sapphire substrates by atmospheric pressure metalorganic chemical vapor deposition (MOCVD). Room temperature and 77K PL measurements were performed using a CW Ar-ion laser (305 nm) and a frequency tripled (280 nm), pulsed, mode-locked Ti: sapphire laser. CW PL emission spectra from the quantum wells (24, 30, 80Å) were all blue shifted with respect to the reference sample. The difference (i. e., the blue shift) between the measured value of peak emission energy from the QW and the band-edge emission from the reference sample was attributed to quantum size effects, and to strain arising due to a significant lattice mismatch between InGaN and GaN. In addition, stimulated emission was observed from an InGaN/GaN single heterojunction in the edge and surface emitting configu-ration at 77K. The narrowing of emission spectra, the nonlinear dependence of output emission intensity on input power density, and the observation of a strongly polarized output are presented. 相似文献
4.
Ananth Dodabalapur V. P. Kesan D. P. Neikirk B. G. Streetman M. H. Herman I. D. Ward 《Journal of Electronic Materials》1990,19(3):265-270
In this study, we describe the correlations between the photoluminescence (PL) spectra and electrical properties of pseudomorphic
modulation-doped AlGaAs/InGaAs/GaAs quantum wells (MDQWs) grown by molecular beam epitaxy. In MDQWs, the presence of a large
sheet carrier density contributes significantly to the PL linewidth. At low temperatures (4.2 K), free carrier induced broadening
of the PL linewidth is influenced by the material quality of the structure. At higher temperatures (77 K), differences in
the material quality do not affect the linewidth significantly, and under these conditions the PL linewidth is a good measure
of the sheet carrier density. The ratio of the 77 K to 4.2 K PL linewidths provides useful information about the crystalline
quality of the MDQW structures as illustrated by the correlation with 77 K Hall mobility data and a simple model. We present
results of Electron Beam Electroreflectance (EBER) to characterize MDQWs and undoped quantum wells in the AlGaAs/InGaAs/GaAs
material system. Several transitions have been observed and fitted to excitonic Lorentzian lineshapes, providing accurate
estimates of transition energy and broadening parameter at temperatures of 96 K and 300 K. 相似文献
5.
In this study, we describe the effects of rapid thermal annealing on the electrical and optical properties of modulation-doped
quantum wells (MDQWs). The sheet carrier concentration in MDQW structures which have been annealed in contact with a piece
of GaAs tends to decrease with increasing annealing time due to Si auto-compensation in the doped AlGaAs regions. The high
energy cut-off point of 4.2 K PL spectra, which occurs at the Fermi energy, and the 77 K PL linewidth are accurate measures
of sheet carrier density. These two parameters track variations in carrier density produced by annealing. Photoluminescence
spectra also provide additional insight into annealing-induced changes such as Si migration, which causes a degradation in
the mobility of the two-dimensional electron gas. 相似文献
6.
在研究新型高效GaAs基三结和四结太阳电池过程中,研究者努力寻找一种既满足能隙约为1eV,同时又与GaAs衬底晶格匹配的半导体材料。通过调节组分,GaInNAs可同时满足上述两个特性,因此GaInNAs被认为是制备新型高效多结GaAs基太阳电池的理想材料。但实际上,制备高晶体质量GaInNAs材料十分困难,造成所制备的器件性能低下,未能达到实际要求。探讨了导致GaInNAs材料生长困难的机理,并对当前GaAs基GaInNAs太阳电池材料的研究历程和技术现状进行了概述。在此基础上,展望了GaInNAs技术的未来走向。 相似文献
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GaInNAs是一种直接带隙半导体材料,在长彼长(1.30和 1.55μm)光通信系统 中具有广阔的应用前景.通过调节 In和 N的组分,既可获得应变 GaInNAs外延材料,也可制 备GaInNAs与GaAs匹配的异质结构,其波长覆盖范围为0.9-N2.0μm.GaInNAs/GaAs 量子阱激光器的特征温度为 200 K,远大于现行 GaInNAsP/InP激光器的特征温度(T0=50 K). GaInNAs光电子器件的此优异特性,对于提高光纤通信系统的稳定性、可靠寿命具有特 别重要的意义.由于GaInNAs和具有高反射率(高达99%)AI(Ga)As/GaAs的分布布拉格 反射镜(DBR)可生长在同-GaAs衬底上,因此它是长波长(1.30和 1.55 μm)垂直腔面 发射激光器(VCSEL)的理想材料.垂直腔面发射激光器是光纤通信、互联网和光信号处理的 关键器件. GaAs基的超高速集成电路(IC)已有相当成熟的工艺.如果 GaInNAs-VCSEL 与 GaAs-IC相结合,将使光电集成电路(OEIC)开拓出崭新的局面.本文还报道我们课题 组研制高质量 GaNAs/GaAs超晶格和大应变 InGaAs/GaAs量子阱结构取 相似文献
9.
本文用4.2K光致发光研究了LEC GaAs的热感生缺陷.热退火时样品分别为无包封,包封或用一个未掺杂的SI-GaAs片覆盖.退火温度为650-850℃,退火在不同气氛下进行(真空,H_2,N_2,H_2+N_2或H_2+As_2). 与缺陷有关的发光带有1.443eV,1.409ev和0.67eV发光带.1.443eV发光带不仅在富Ga的GaAs中出现,而且在富As的热稳定性好的SI-GaAs晶体并经过850℃(在H_2中)热退火的样品中也观测到此发光带.这可能是在退火过程中促进反位缺陷GaAs的形成.1.443eV发光带与GaAs有关.GaAs晶体在H_2中退火后1.409eV峰很强,但在真空中退火末探测到此发光带.文中提出它可能是热退火时氢原子扩散到GaAs晶体中并与某些缺陷结合成络合物的新观点. 相似文献
10.
研究了分子束外延GaAs/Si光致发光谱的激发强度和温度依赖关系。确定出2个本征发光峰,分别对应于导带至m_J=±3/2和m_J=±1/2价带的复合。这种价带的移动和分裂归因于由GaAs和Si的热膨胀系数不同所引起的GaAs层双轴张应力。还观测到4个非本征发光峰,分别为导带至m_J=±1/2碳受主态发光、可能与缺陷有关的发光以及可能由Mn和Cu受主杂质引起的发光。室温下将GaAs/Si和GaAs/GaAs材料的光反射谱进行比较,前者明显向低能移动约8meV,观测到3个特征谱结构,与光致发光结果相一致。 相似文献
11.
We have performed nitrogen atomic-layer doping into GaAs, AlGaAs, and AlGaAs/GaAs single quantum wells using atomic nitrogen
cracked by a hot tungsten filament. While the atomic-layer-doped GaAs layers show a series of sharp and strong photoluminescence
lines relating to excitons bound to nitrogen atoms at 8K, atomic-layer-doped AlGaAs layers show several broad nitrogen-related
lines. For the atomic-layer-doped single quantum well at the center of the GaAs layer, the quantum well luminescence itself
disappears and a dominant and sharp luminescence is observed at a longer wavelength. It is found that the As pressure during
the atomic-layer doping greatly affects the luminescence characteristics. 相似文献
12.
Wayne H. Knox 《Solid-state electronics》1989,32(12):1057-1063
Optical excitations near the bandedge of GaAs quantum wells have revealed interesting information about carrier scattering and renormalization. The extension of these studies to modulation-doped quantum wells is discussed. 相似文献
13.
S. Bürkner M. Maier E. C. Larkins W. Rothemund E. P. O’reilly J. D. Ralston 《Journal of Electronic Materials》1995,24(7):805-812
The dependence of the impurity-free interdiffusion process on the properties of the dielectric cap layer has been studied,
for both unstrained GaAs/AlxGa1−xAs and pseudomorphic Iny Ga1−yAs/GaAs MQW structures grown by molecular beam epitaxy. The influence of the cap layer thickness, composition, and deposition
technique on the degree of interdiffusion were all systematically investigated. Electron-beam evaporated SiO2 films of varying thickness, chemical-vapor-deposited SiOxNy films of varying composition, and spin-on SiO2 films were used as cap layers during rapid thermal annealing (850-950°C). Photoluminescence at 10K has been employed to determine
the interdiffusioninduced bandgap shifts and to calculate the corresponding Al-Ga and In-Ga interdiffusion coefficients. The
latter were found to increase with the cap layer thickness (e-beam SiO2) up to a limit determined by saturation of the outdiffused Ga concentration in the SiO2 caps. A maximum concentration of [Ga] = 4–7 ×1019 cm−3 in the SiO2 caps was determined using secondary ion mass spectroscopy profiling. Larger band-edge shifts are also obtained when the oxygen
content of SiOxNy cap layers is increased, although the differences are not sufficiently large for a laterally selective interdiffusion process
based on variations in cap layer composition alone. Much larger differences are obtained by using different deposition techniques
for the cap layers, indicating that the porosity of the cap layer is a much more important parameter than the film composition
for the realization of a laterally selective interdiffusion process. For the calculated In0.2Ga0.8As/GaAs interdiffusion coefficients, activation energies EA and prefactors Do were estimated to ranging from 3.04 to 4.74 eV and 5 × Kh−3 to 2 × 105 cm2/s, respectively, dependent on the cap layer deposition technique and the depth of the MQW from the sample surface. 相似文献
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报道了一种具有高速响应特性的GaAs基长波长谐振强增强型(RCE)光探测器,它采用分子束外延技术(MBE)在GaAs衬底上直接生长GaAs/AlAs布拉格反射镜(DBR)和GaInNAs/GaAs多量子阱吸收层而形成,解决了GaAs系材料只能对短波长光响应的问题,实现了GaAs基探测器对长波长光的响应。该器件在峰值响应波长1296.5nm处获得了17.4%的量子效率,响应谱线半宽为11nm,零偏置时的暗电流密度8.74×10-15A/μm2,具有良好的暗电流特性。通过RC常数测量计算得到器件的3dB带宽为4.82GHz。 相似文献
17.
Niu Zhichuan Han Qin Ni Haiqiao Yang Xiaohong Xu Yingqiang Du Yun Zhang Shiyong Peng Hongling Zhao Huan Wu Donghai Li Sh 《半导体学报》2005,26(9):1860-1864
Material growth and device fabrication of the first 1.3μm quantum well (QW) edge emitting laser diodes in China are reported.Through the optimization of the molecular beam epitaxy (MBE) growth conditions and the tuning of the indium and nitrogen composition of the GaInNAs QWs,the emission wavelengths of the QWs can be tuned to 1.3μm.Ridge geometry waveguide laser diodes are fabricated.The lasing wavelength is 1.3μm under continuous current injection at room temperature with threshold current of 1kA/cm2 for the laser diode structures with the cleaved facet mirrors.The output light power over 30mW is obtained. 相似文献
18.
采用室温Raman散射和低温光致发光(PL)谱,对以TMG,固体As和固体In作为分子束源的MOMBE法生长的GaAs/In_xGa_(1-x)As(x=0.3)单层异质结构和多量子阱结构中InGaAs应变层的临界厚度进行了实验研究。由应变引起的Raman散射峰位移,以及PL谱峰位置与应变和无应变状态下一维有限深势阱跃迁能量计算结果的比较可见,在In组分含量x=0.3的情况下,临界厚度H_c≤5nm,小于能量平衡理论的结果,而与力学平衡模型的理论值相近。 相似文献
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