基于锑化物二类超晶格的多色红外探测器研究进展

近年来InAs/GaSb二类超晶格红外探测器在材料晶体结构生长、器件结构设计与成像应用方面取得了飞速发展。尤其在多色红外探测方面,二类超晶格材料以其具备的带隙可调、暗电流小、量子效率高、材料均匀性高,以及成本低等优越性能,使其逐步成为第三代红外焦平面探测器的优选材料。本文阐述了锑化物窄带隙半导体研究中心的锑化物多色红外探测器研究进展。本团队成功实现了低噪声、高量子效率以及低光学串扰的短/中、短/长、中/长、长/长、中/长/甚长波等多种高性能多色红外探测器研制。     

新奇半导体低维结构的自组织生长

文章介绍了自组织生长半导体量子线、量子点和量子环的进展,同时介绍了这些低维半导体材料在光电子和通信等领域应用情况.此外,对这些材料的一些测试方法也进行了介绍.     

Quantum frequency down-conversion of single photons at 1552 nm from single InAs quantum dot

Near-infrared single photon sources in telecommunication bands, especially at 1550 nm, are required for long-distance quantum communication. Here a down-conversion quantum interface is implemented, where the single photons emitted from single In As quantum dot at 864 nm is down converted to 1552 nm by using a fiber-coupled periodically poled lithium niobate(PPLN) waveguide and a 1.95 μmm pump laser, and the frequency conversion efficiency is ~40%. The singlephoton purity of quantum dot emission is preserved during the down-conversion process, i.e., g~((2))(0), only 0.22 at 1552 nm.This present technique advances the Ⅲ-Ⅴ semiconductor quantum dots as a promising platform for long-distance quantum communication.     

1.3μm GaAs基量子点垂直腔面发射激光器结构设计与分析

结合垂直腔面发射激光器（VCSEL）原理以及量子点增益特点，计算了不同结构VCSEL的腔内损耗和量子点的模式增益.分析了激光器阈值特性以及氧化限制层对光损耗的影响.设计了含 氧化限制层的13μm量子点VCSEL结构. 关键词： 量子点 垂直腔面发射激光器 增益     

Self-Organized InAs Quantum Wires on GaAs （331）A Substrates

Self-organized InAs quantum wires (QWRs) were fabricated on the step edges of the GaAs (331)A surface by molecular beam epitaxy. The lateral size of InAs QWRs was saturated by the terrace width (i.e., 9Ohm) while the size along the step lines increased with the increasing thicknesses of the InAs layers, up to 1100nm. The height of InAs QWRs varied from 7.9nm to 13nm. The evolution of the morphology of InAs QWRs was attributed to the diffusion .andsotropy of In adatoms.     

Wet etching and passivation of GaSb-based very long wavelength infrared detectors

The etching and passivation processes of very long wavelength infrared (VLWIR) detector based on the InAs/GaSb/AlSb type-II superlattice have been studied. By studying the effect of each component in the citric acid solution (citric acid, phosphoric acid, hydrogen peroxide, deionized water), the best solution ratio is obtained. After comparing different passivation materials such as sulfide + SiO₂, Al₂O₃, Si₃N₄ and SU8, it is found that SU8 passivation can reduce the dark current of the device to a greater degree. Combining this wet etching and SU8 passivation, the R₀A of VLWIR detector with a mesa diameter of 500 μm is about 3.6 Ω ·cm² at 77 K.     

GaAs-Based Metamorphic Long-Wavelength InAs Quantum Dots Grown by Molecular Beam Epitaxy

A bilayer stacked InAs/GaAs quantum dot structure grown by molecular beam epitaxy on an In0.05Ga0.95As metamorphic buffer is investigated. By introducing a InGaAs：Sb cover layer on the upper InAs quantum dots （QDs） layers, the emission wavelength of the QDs is extended successfully to 1.533 μm at room temperature, and the density of the QDs is in the range of 4× 10^9-8 ×10^9cm^-2. Strong photoluminescence （PL） intensity with a full width at half maximum of 28.6meV of the PL spectrum shows good optical quality of the bilayer QDs. The growth of bilayer QDs on metamorphic buffers offers a useful way to extend the wavelengths of GaAs-based materials for potential applications in optoeleetronic and quantum functional devices.     

High quality above 3-μm mid-infrared InGaAsSb/AIGaInAsSb multiple-quantum well grown by molecular beam epitaxy

The GaSb-based laser shows its superiority in the 3-4 ~tm wavelength range. However, for a quantum well （QW） laser structure of InGaAsSb/AIGaInAsSb multiple-quantum well （MQW） grown on GaSb, uniform content and high com- pressive strain in InGaAsSb/A1GaInAsSb are not easy to control. In this paper, the influences of the growth tempera- ture and compressive strain on the photoluminescence （PL） property of a 3.0μm lnGaAsSb/A1GaInAsSb MQW sample are analyzed to optimize the growth parameters. Comparisons among the PL spectra of the samples indicate that the Ino.485GaAso.184Sb/Alo.3Gao.45Ino.25Aso.22Sbo.78 MQW with 1.72% compressive strain grown at 460 ~C posseses the op- timum optical property. Moreover, the wavelength range of the MQW structure is extended to 3.83 μm by optimizing the parameters.     

InAs 单量子点中级联辐射光子的关联测量

利用分子束外延生长InAs单量子点样品,温度为5 K时,测量了单量子点中单、双激子自发辐射的荧光(PL)光谱.研究了单、双激子发光强度随激发功率的变化及对应发光峰的偏振特性和精细结构劈裂.基于Hanbury-Brown Twiss(HBT) 实验,测量了单、双激子间发光光谱的关联函数,证实了其发光过程为级联发射过程. 关键词： InAs 单量子点 单、双激子 荧光光谱 级联辐射     

金纳米颗粒调控量子点激子自发辐射速率

将InAs/GaAs量子点样品薄膜置于覆盖有直径为50 nm的金(Au)纳米颗粒的硅衬底上,可以调控量子点激子的自发辐射速率.实验发现,当量子点浸润层距离Au纳米颗粒表面15—35 nm时,激子自发辐射速率受到抑制,且距离为19 nm时抑制作用最大,导致量子点激子的自发辐射速率减小到没有Au纳米颗粒时自发辐射速率的10^-3.基于经典的偶极辐射模型模拟计算的激子自发辐射速率与实验结果一致.