共查询到20条相似文献,搜索用时 83 毫秒
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InGaAs/GaAs量子点红外探测器 总被引:1,自引:2,他引:1
与量子阱红外探测器相比,量子点红外探测器具有不制作表面光栅就能在垂直入射红外光照射下工作以及工作温度更高等优势。然而,目前阻碍量子点红外探测器性能提高的技术瓶颈主要来自组装量子点较差的大小均匀性、较低的量子点密度以及垂直入射下子带跃迁吸收效率低等原因。利用分子束外延技术研究了如何从量子点材料生长和器件设计两方面来克服这些困难,并且制作了几种不同结构的InGaAs/GaAs量子点红外探测器。 在77 K时,这些器件在垂直入射条件下观察到了很强的光电流信号。 相似文献
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报道调制掺杂AlGaAs/InGaAs/GaAs应变量子阱结构的分子束外延生长、变温霍尔效应和电化学c—v测量,并对输运性质进行了讨论。用这种材料研制的PM-HEMT(pseudomorphic high electron mobility transistors)器件,栅长0.4μm,在12GHz下噪声系数1.03dB,相关增益7.5dB。 相似文献
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Structural and infrared absorption properties of self-organized InGaAs/GaAs quantum dots multilayers
Q. D. Zhuang J. M. Li Y. P. Zeng L. Pan Y. H. Chen M. Y. Kong L. Y. Lin 《Journal of Electronic Materials》1999,28(5):503-505
Self-organized InGaAs/GaAs quantum dots (QDs) stacked multilayers have been prepared by solid source molecular beam epitaxy.
Cross-sectional transmission electron microscopy shows that the InGaAs QDs are nearly perfectly vertically aligned in the
growth direction [100]. The filtering effect on the QDs distribution is found to be the dominant mechanism leading to vertical
alignment and a highly uniform size distribution. Moreover, we observe a distinct infrared absorption from the sample in the
range of 8.6–10.7 μm. This indicates the potential of QDs multilayer structure for use as infrared photodetector. 相似文献
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Daniel C. Bertolet Jung-Kuei Hsu Farid Agahi Kei May Lau 《Journal of Electronic Materials》1990,19(9):967-974
In this paper we describe a study of strained quantum wells (QWs) as a means to experimentally observe the critical thickness
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c) for the formation of interfacial misfit dislocations. Two material systems were investigated: GaAs/In0.11Ga0.89As, in which the QW layers are under biaxialcompression, and Al0.35Ga0.65As/GaAs0.82P0.18, in which the QW layers are under biaxialtension. Samples were grown by atmospheric pressure organometallic chemical vapor deposition, and characterized by low-temperature
photoluminescence (PL), x-ray diffraction, optical microscopy, and Hall measurements. For both material systems, the observed
onset of dislocation formation agrees well with the force-balance model assuming a double-kink mechanism. However, overall
results indicate that the relaxation is inhomogeneous. Annealing at 800–850° C had no significant effect on the PL spectra,
signifying that even layers that have exceededh
c and have undergone partial relaxation are thermodynamically stable against further dislocation propagation. 相似文献
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Low pressure metalorganic vapor phase epitaxy grown strained InGaAs/GaAs quantum well structures have been characterized by
photoluminescence and x-ray diffraction. It is shown that beyond the pseudomorphic limit, these structures show considerable
gallium/indium interdiffusion at the interfaces and partial strain relaxation in the quantum well layers. 相似文献
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采用VarianGenⅡMBE生长系统研究了InGaAs/GaAs应变层单量子阶(SSQW)激光器结构材料。通过MBE生长实验,探索了In_xGa_(1-x)tAs/GaAsSSQW激光器发射波长(λ)与In组分(x)和阱宽(L_z)的关系,并与理论计算作了比较,两者符合得很好。还研究了材料生长参数对器件性能的影响,主要包括:Ⅴ/Ⅲ束流比,量子阱结构的生长温度T_g(QW),生长速率和掺杂浓度对激光器波长、阈值电流密度、微分量子效率和器件串联电阻的影响。以此为基础,通过优化器件结构和MBE生长条件,获得了性能优异的In_(0.2)Ga_(0.8)As/GaAs应变层单量子阱激光器:其次长为963nm,阈值电流密度为135A/cm ̄2,微分量子效率为35.1%。 相似文献
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InGaAs quantum dots formed in tetrahedral-shaped recesses on GaAs (111)B grown by metalorganic chemical vapor deposition 总被引:1,自引:0,他引:1
Yoshiki Sakuma Masashi Shima Yuji Awano Yoshiro Sugiyama Toshiro Futatsugi Naoki Yokoyama Kazuhito Uchida Noboru Miura Takashi Sekiguchi 《Journal of Electronic Materials》1999,28(5):466-480
Novel semiconductor quantum dots (QDs), grown in tetrahedral-shaped recesses (TSRs) formed on a (111)B GaAs substrate, are
described from both material science and device application points of view. After explaining the fabrication procedure for
TSRs, growth of InGaAs QDs and their optical properties are explained. It is revealed that an InGaAs QD of indium-rich chemical
composition is formed spontaneously at the bottom of each TSR. The mechanism of the QD formation is discussed in detail. It
is proved from magneto-photoluminescence that the QDs actually have optical properties peculiar to zero-dimensional confinement.
Several experimental results indicating excellent growth controllability of the QDs are presented. Finally, recent challenges
to apply the QDs to electronic memory devices are reported. Two kinds of devices, where the position of individual QD is artificially
controlled, are proposed for the first time and the preliminary experimental results are explained. 相似文献
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S. Rouvimov Z. Liliental-Weber W. Swider J. Washburn E. R. Weber A. Sasaki A. Wakahara Y. Furkawa T. Abe S. Noda 《Journal of Electronic Materials》1998,27(5):427-432
Vertical ordering in stacked layers of InAs/GaAs quantum dots is currently the focus of scientific research because of its
potential for optoelectronics applications. Transmission electron microscopy was applied to study InAs/GaAs stacked layers
grown by molecular-beam-epitaxy with various thicknesses of GaAs spacer. Thickness dependencies of quantum dot size and their
ordering were observed experimentally and, then, compared with the results of strain calculations based on the finite element
method. The vertical ordering did occur when the thickness of the GaAs spacer was comparable with the dot height. The ordering
was found to be associated with relatively large InAs dots on the first layer. Quantum dots tend to become larger in size
and more regular in plane with increasing numbers of stacks. Our results suggest that the vertical ordering is not only affected
by strain from the InAs dots on the lower layer, but by total strain configuration in the multi-stacked structure. 相似文献
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本文研究了斜切割(100)Ge衬底上InxGa1-xAs/GaAs量子阱结构的分子束外延生长(In组分为0.17或者0.3)。所生长的样品用原子力显微镜、光致发光光谱和高分辨率透射电子显微镜进行了测量和表征。结果发现,为了生长没有反相畴的GaAs缓冲层,必须对Ge衬底进行高温退火。在GaAs外延层和InxGa1-xAs/GaAs量子阱结构的生长过程中,生长温度是一个至关重要的参数。文中讨论了温度对于外延材料质量的影响机理。通过优化生长温度,Ge衬底上的InxGa1-xAs/GaAs量子阱结构的光致发光谱具有很高的强度、很窄的线宽,样品的表面光滑平整。这些研究表面Ge 衬底上的III-V族化合物半导体材料有很大的器件应用前景。 相似文献
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Molecular beam epitaxy growth of an InxGa1-xAs/GaAs quantum well(QW) structure(x equals to 0.17 or 0.3) on offcut(100) Ge substrate has been investigated.The samples were characterized by atomic force microscopy,photoluminescence(PL),and high resolution transmission electron microscopy.High temperature annealing of the Ge substrate is necessary to grow GaAs buffer layer without anti-phase domains.During the subsequent growth of the GaAs buffer layer and an InxGa1-xAs/GaAs QW structure,temperature plays a key role. The mechanism by which temperature influences the material quality is discussed.High quality InxGa1-x As/GaAs QW structure samples on Ge substrate with high PL intensity,narrow PL linewidth and flat surface morphology have been achieved by optimizing growth temperatures.Our results show promising device applications forⅢ-Ⅴcompound semiconductor materials grown on Ge substrates. 相似文献