InAs基室温中波红外探测器的液相外延生长

材料质量好坏对于获得高性能红外探测器至关重要。提出决定材料质量的关键点在于精准控制材料结构中层与层之间的晶格失配度，报道了晶格失配对材料质量和器件暗电流性能的影响。实验结论表明在液相外延技术生长的InAs/InAsSbP材料体系中，InAs和InAsSbP间的晶格失配不是越小越好，而是有一个最佳值。如果晶格失配偏离这个值，不管是偏大还是偏小，材料的质量都会恶化。阐述了如何调整生长参数以获得合适的晶格失配度。制备了具有适宜晶格失配度的红外探测器件，该探测器零偏压下的室温峰值探测率为6.8×10⁹ cm Hz^1/2W^-1，与国际商用InAs探测器的指标相当。     

InAs/GaSb II类超晶格中波红外探测器

InAs/GaSb II类超晶格探测器是近年来国际上发展迅速的红外探测器,其优越性表现在高量子效率和高工作温度,以及良好的均匀性和较低的暗电流密度,因而受到广泛关注。报道了InAs/GaSb超晶格中波材料的分子束外延生长和器件性能。通过优化分子束外延生长工艺,包括生长温度和快门顺序等,获得了具原子级表面平整的中波InAs/GaSb超晶格材料,X射线衍射零级峰的双晶半峰宽为28.8,晶格失配a/a=1.510-4。研制的p?鄄i?鄄n单元探测器在77 K温度下电流响应率达到0.48 A/W,黑体探测率为4.541010 cmHz1/2W,峰值探测率达到1.751011 cmHz1/2W。     

InAs/GaSb II型超晶格红外探测器的研究进展

InAs/GaSb Ⅱ型超晶格材料理论上性能优于HgCdTe、InSb等红外探测材料,基于成熟的Ⅲ-V族化合物材料与器件工艺,使得Ⅱ型超晶格材料容易满足均匀大面阵、双色或多色集成等红外探测器的要求,因而InAs/GaSb Ⅱ型超晶格材料将逐步替代HgCdTe、InSb等材料成为第三代红外探测器的首选材料。本文阐述了InAs/GaSb超晶格红外探测器的基本原理、以及材料生长和器件结构,并对其研究进展进行了综述性介绍。     

InAs/GaSb超晶格中波焦平面材料的分子束外延技术

报道了InAs/GaSb超晶格中波材料的分子束外廷生长技术研究.通过改变GaSb衬底上分子束外延InAs/GaSb超晶格材料的衬底温度,以及界面的优化等,改善超晶格材料的表面形貌和晶格失配,获得了晶格失配△a/a=1.5×10-4,原子级平整表面的InAs/GaSb超晶格材料,材料77 K截止波长为4.87 μm.     

2～5μm InAs/GaSb超晶格红外探测器

采用分子束外延方法在GaSb和GaAs衬底上生长了不同周期厚度的InAs/GaSb高质量Ⅱ型能带结构超晶格红外探测器,其探测波长覆盖2～5 μm红外波段.采用高分辨透射电子显微镜、原子力显微镜、X射线衍射测试、室温与低温光电流响应谱及室温与低温光荧光谱等多种测试手段检验了分子束外延生长在不同衬底上的超晶格材料质量与光学...     

势垒型InAs/InAsSb II类超晶格红外探测器研究进展（特邀）

红外探测技术在卫星侦察、军事制导、天文观测、医疗检测、现代通信等重要领域发挥着关键作用。II类超晶格（T2SLs）红外探测器作为继碲镉汞探测器之后的新一代红外探测材料,在稳定性、可制造性和成本等方面具有独特优势。势垒型InAs/InAsSb T2SLs红外探测器是最具潜力的T2SLs红外探测器之一,近年来其关键性能得到了稳步提高,但仍受吸收系数低、异质外延生长困难和暗电流大等因素的制约。文中综述了III-V族T2SLs的发展历程,分析了势垒型InAs/InAsSb T2SLs红外探测器的不同势垒结构、关键性能和发展趋势,指出了势垒型InAs/InAsSb T2SLs红外探测器需要解决的关键问题和未来发展方向。     

新型热释电单晶材料与红外探测器的研究

主要阐述了当前热释电红外探测器的发展状况,并重点介绍了我国尤其是我们在新型热释电材料以及红外探测器方面的主要进展和成果。弛豫铁电单晶是一类具有优异压电性能的新型材料,同时我们发现该类晶体还具有优异的热释电性能。我们所生长的PMNT单晶的热释电系数超过15.3×10^-4cm^-2.K^-1,Mn-PMNT的介电损耗降至0.0005,探测优值达到40.2×10^-5Pa^-1/2,高居里温度点单晶PIMNT的居里温度达到180℃以上。与合作单位一起利用该类晶体研制的红外探测器的性能远优于利用传统热释电材料（如LiTaO₃）制作的探测器,其比探测率达到1.07×10⁹ cm·Hz^1/2/·W^-1,说明利用该新型弛豫铁电单晶制作的红外探测器具有广阔的应用前景。     

晶格失配度达2.6%的波长扩展InGaAs/InP光电探测器结构

利用气态源分子束外延,采用相对较高的1.1%μm-1失配度变化速率,在InAlAs递变缓冲层上生长了晶格失配度高达2.6%的InP基InGaAs变形晶格探测器结构,并与采用相同结构而晶格失配度为1.7%和2.1%的探测器样品进行了比较。通过原子力显微镜、X射线衍射、光致发光和器件特性测试对样品进行了表征。结果显示该晶格失配度达2.6%的探测器结构具有较好的表面形貌、较大的晶格弛豫度和理想的光学特性。器件室温截止波长约为2.9μm,直径为300μm的器件室温下在反向偏压10mV时的暗电流为2.56μA。     

短波红外铟镓砷探测器材料表面缺陷研究

短波红外铟镓砷(InGaAs)探测器材料的表面缺陷是发展大规模小像元焦平面阵列的核心问题之一,其中与衬底晶格失配的延伸波长探测器材料的表面缺陷控制起来尤为困难。优化了分子束外延(Molecular Beam Epitaxy, MBE) In束源炉的温度设置。结果表明,In炉上下温差为130℃时所生长的短波红外晶格失配In_0.83Ga_0.17As材料的表面缺陷密度最小,由此有效地将材料的表面缺陷密度由3000 cm^-2左右降至约500 cm^-2。结合短波红外晶格失配InGaAs材料的室温光致发光测试,经分析可知,In束源炉上下温差存在最优值的现象是由于In金属液滴和炉子顶部杂质引起卵形缺陷这两种机制的共同作用而引起的。本文制备的低缺陷密度晶格失配InGaAs探测器材料为发展高性能延伸波长短波红外焦平面阵列打下了基础。     

MBE生长InAs/GaSbⅡ类超晶格材料的界面控制方法分析

本文系统地介绍了MBE外延生长InAs/GaSb Ⅱ类超晶格材料的界面控制方法,主要包括生长中断法、表面迁移增强法、Ⅴ族元素浸润法和体材料生长法。短波（中波）InAs/GaSb超晶格材料界面采用混合（mixed-like）界面,控制方法以生长中断法为主;长波（甚长波）超晶格材料界面采用InSb-like界面,控制方法采用表面迁移增强法（migration-enhanced epitaxy, MEE）或Sb soak法及体材料生长相结合。讨论分析了InAs/GaSb超晶格材料界面类型选择的依据,简述了界面控制具体实施理论,以及相关研究机构对于不同红外探测波段的超晶格材料界面类型及控制方法的选择。通过界面结构外延生长工艺设计即在界面控制方法的基础上进行快门顺序实验设计,有效地提高界面层的应力补偿效果,这对于长波、甚长波及双色（甚至多色）超晶格材料的晶体质量优化和器件性能提升具有重要意义。     

Effect of multicomponent InAsSbP matrix surface on formation of InSb quantum dots at MOVPE growth

Indium-antimonide quantum dots (7–9 × 10⁹ cm²) are produced on an InAs(001) substrate by metal-organic vapor-phase epitaxy at a temperature of T = 440°C. Epitaxial deposition occurred simultaneously onto an InAs binary matrix and an InAsSbP quaternary alloy matrix layer lattice-matched to the InAs substrate in terms of the lattice parameter. Transformation of the quantum-dot shape and size is studied in relation to the chemical composition of the working matrix surface, onto which the quantum dots are deposited. The use of a multicomponent layer makes it possible to control the lattice parameter of the matrix and the strains produced in the system during the formation of self-assembled quantum dots.     

Electroluminescence of InAs/InAs(Sb)/InAsSbP LED heterostructures in the temperature range 4.2–300 K

The electroluminescence of InAs/InAsSbP and InAsSb/InAsSbP LED heterostructures grown on InAs substrates is studied in the temperature range T = 4.2–300 K. At low temperatures (T = 4.2–100 K), stimulated emission is observed for the InAs/InAsSbP and InAsSb/InAsSbP heterostructures with an optical cavity formed normal to the growth plane at wavelengths of, respectively, 3.03 and 3.55 μm. The emission becomes spontaneous at T > 70 K due to the resonant “switch-on” of the CHHS Auger recombination process in which the energy of a recombining electron–hole pair is transferred to a hole, with hole transition to the spin–orbit-split band. It remains spontaneous up to room temperature because of the influence exerted by other Auger processes. The results obtained show that InAs/InAs(Sb)/InAsSbP structures are promising for the fabrication of vertically emitting mid-IR lasers.     

用液相外延法生长3～7μm波段InAs/InAs1-ySby及其光学和电学性质

用液相外延(LPE)法在InAs衬底上生长了3～7μm波段的InAs1-ySby外延层,研究了外延多层的组份与禁带宽度和晶格常数的关系。用光学显微镜、傅立叶变换红外(FTIR)透射、光荧光(PL)谱测试以及偏振光椭圆仪研究了外延材料的光学特性。电学性质是将计算值与实测有效霍尔(Hall)参数的厚度关系拟合得到的。结果表明,本文生长的材料在中红外光伏型探测器上具有良好的应用前景。     

长波InAsSb材料的结构特性研究

用熔体外延(ME)法在InAs衬底上生长了InAsSb外延层,用扫描电子显微镜(SEM)观察了样品的横截面,并测量出外延层的厚度达到100μm,用X-射线衍射(XRD)谱研究了InAsSb外延层的结构性质。测量结果表明,InAs/InAs0.023Sb0.977单晶具有相当完美的晶体取向结构及良好的结晶质量,这可能得益于100μm的外延层厚度基本消除了外延层与衬底之间晶格失配的影响。电子探针微分析(EPMA)测量的元素分布图像显示,Sb(锑)元素在外延层中的分布相当均匀。     

Radiative recombination via direct optical transitions in In1 −x GaxAs (0≤x≤0.16) solid solutions

Photoluminescence from In_1?x Ga_xAs (0≤x≤0.16) solid solution epilayers LPE-grown on (111)InAs substrates and electroluminescence from p-n junctions on their bases have been studied in the temperature range 77–450 K. Despite the negative lattice mismatch between epilayer and substrate, radiative recombination in epilayers occurs via direct optical transitions ensuring a high internal quantum efficiency of luminescence (6% at 295 K).     

Epitaxial growth and characterization of DyP/GaAs, DyAs/GaAs, and GaAs/DyP/GaAs heterostructures

There is a significant interest in the area of improving high temperature stable contacts to III-V semiconductors. Two attractive material systems that offer promise in this area are dysprosium phosphide/gallium arsenide (DyP/GaAs) and dysprosium arsenide/gallium arsenide (DyAs/GaAs). Details of epitaxial growth of DyP/GaAs and DyAs/GaAs by molecular beam epitaxy (MBE), and their characterization by x-ray diffraction, transmission electron microscopy, atomic force microscopy, Auger electron spectroscopy, Hall measurements, and high temperature current-voltage measurements is reported. DyP is lattice matched to GaAs, with a room temperature mismatch of less than 0.01% and is stable in air with no sign of oxidation, even after months of ambient exposure. Both DyP and DyAs have been grown by solid source MBE using custom designed group V thermal cracker cells and group III high temperature effusion cells. High quality DyP and DyAs epilayer were consistently obtained for growth temperatures ranging from 500 to 600°C with growth rates between 0.5 and 0.7 μm/h. DyP epilayers are n-type with electron concentrations of 3 × 10²⁰ to 4 × 10²⁰ cm⁻³, room temperature mobilities of 250 to 300 cm²/V·s, and a barrier height of 0.81 eV to GaAs. DyAs epilayers are also n-type with carrier concentrations of 1 × 10²¹ to 2 × 10²¹ cm⁻³, and mobilities between 25 and 40 cm²/V·s.     

320×256 InAs/GaSb超晶格中/短波双色探测器组件研制

InAs/GaSb超晶格材料制备的新型红外器件在最近十几年得到了迅速发展。文中开展了InAs/GaSb二类超晶格中/短波双色焦平面探测器组件研制,设计了中/短波双色叠层背靠背二极管芯片结构,用分子束外延技术生长出结构完整、表面平整、低缺陷密度的PNP结构超晶格材料,制备出性能优良的320×256双色焦平面探测器组件,对探测器组件进行了测试分析。结果显示,在77 K下中波二极管RA值达到26.0 kΩ·cm2,短波的RA值为562 kΩ·cm2。光谱响应特性表明短波响应波段为1.7~3 μm,中波为3~5 μm,满足设计要求。双色峰值探测率达到中波3.12×1011 cm·Hz1/2W-1,短波1.34×1011 cm·Hz1/2W-1。响应非均匀性中波为9.9%,短波为9.7%。中波有效像元率为98.46%,短波为98.06%。     

Modeling InAs/GaSb and InAs/InAsSb Superlattice Infrared Detectors

InAs/GaSb and InAs/InAsSb type II superlattices have been proposed as promising alternatives to HgCdTe for the photon-absorbing layer of an infrared detector. When combined with a barrier layer based on an InAs/AlSb superlattice or an AlSbAs alloy, respectively, they can be used to make diffusion-limited “barrier” detectors with very low dark currents. In this work we compare theoretical simulations with experimental bandgap and photoabsorption data for such superlattices, spanning from the mid to the long-wave infra-red (2.3–12 μm). The spectral response of detectors based on these materials is also simulated. The simulations are based on a version of the k · p model developed by one of the authors, which takes interface contributions and bandgap bowing into account. Our results provide a way of assessing the relative merits of InAs/GaSb and InAs/InAsSb superlattices as potential detector materials.     

The temperature dependence of internal parameters of disc laser diodes InAs/InAsSbP

For disc lasers based on the InAs/InAsSbP heterostructure with a generation wavelength of 3.03–3.06 μm, the internal quantum yield of luminescence and rates of radiative and nonradiative recombination in a temperature range of 85–120 K are determined. It is established that as the temperature increases, the relative contribution of the rate of nonradiative recombination to the density of the threshold current increases from 89.9 to 92.8%. It is shown that the most probable mechanisms of nonradiative transitions in the InAs/InAsSbP disc heterolasers can be the CHCC and CHSH Auger processes with involvement of phonons. Coefficients of total losses for two experimentally observed generation bands are determined, and the maximum level of the internal optical losses is estimated. The figure of merit of the resonator of the InAs/InAsSbP disc heterolaser is ～10⁴.