In(Ga)As量子点红外探测器

讨论了量子点红外探测器的工作原理、性能参数、暗电流形成机理及其优势,介绍了In(Ga)As量子点红外探测器的主要结构、性能和取得的最新结果,最后探讨了如何进一步提高量子点红外探测器的性能。指出要实现量子点红外探测器的优势,必须优化量子点生长条件,让量子点更小、更均匀和密度更大;必须提高量子点的掺杂控制和掺杂水平,实现每个量子点中有1～2个电子;必须降低量子点生长中引入的应力,增加量子点有源区的层数;此外,还必须寻求新的量子点红外探测器结构。     

CdTe和CdTe/CdS量子点的量子尺寸效应

利用水热法合成了三种不同尺寸的单核CdTe量子点和核壳CdTe/CdS量子点。应用Top-hat Z-scan技术在纳秒、皮秒、飞秒激光脉冲作用下研究了三种不同尺寸单核CdTe量子点的非线性吸收特性。实验结果表明:在不同激光脉冲作用下三种不同尺寸的CdTe量子点的非线性吸收特性均表现为饱和吸收,并且均呈现出随着量子点尺寸的减小,其非线性吸收特性增大的趋势。为了进一步研究量子点尺寸的变化对非线性吸收特性的影响,又在飞秒激光脉冲作用下研究了核壳CdTe/CdS量子点的非线性吸收特性;随着包壳时间的增加,壳层厚度增加,量子点尺寸增加,其非线性吸收特性呈减小趋势,并且核壳CdTe/CdS量子点的非线性吸收特性明显优于单核CdTe量子点;分析讨论了单核CdTe量子点与核壳CdTe/CdS量子点的非线性吸收特性和量子尺寸效应机制,实验结果表明合成的量子点样品均具有良好的量子尺寸效应。     

胶体量子点激光器研究现状和展望（特邀）

2023年诺贝尔化学奖颁发给了Moungi G. Bawendi、Louis E. Brus和Alexei I. Ekimov,以表彰其在量子点领域的开创性研究工作。虽然量子点为基础物理研究提供了理想的平台,但在应用方面还远未展现其天赋。其中,量子点独特的电子结构和可溶液加工特性,使其在低成本、高性能激光领域具有广阔的前景。经过20余年的研究,胶体量子点激光器取得了令人瞩目的进展,然而,目前的胶体量子点激光器仍未实现商业化,这说明人们对胶体量子点激光器基础物理的理解以及对关键制备技术的掌握仍有欠缺。基于此,笔者对胶体量子点激光器在近年来的工作进展进行了梳理,并提出了胶体量子点激光领域所面临的挑战,以及克服这些挑战的研究思路。最后,对胶体量子点激光器的未来前景和潜在应用进行了展望。     

UHV/CVD自对准生长Ge量子点(英文)

在超高真空化学汽相淀积设备(UHV/CVD)上生长了小尺寸、大密度、垂直自对准的Ge量子点。采用原子力显微镜分析量子点的尺寸,可优化其生长温度和时间,在550℃,15s的条件下生长出尺寸最小的量子点,直径30nm,高约2nm。最上层多层结构Ge量子点中岛状量子点的比例为75%,其直径66nm,高11nm,密度4.5×109cm-2。利用透射电子显微镜分析了垂直自对准的Ge量子点的截面形貌,结果表明多层结构Ge量子点是垂直自对准的。Ge量子点及其浸润层的喇曼谱峰位分别为299cm-1和417cm-1,说明Ge量子点是应变的并且界面存在互混现象。采用光荧光谱分析了Ge量子点的光学特性。     

靶向量子点的合成及其在活体成像研究中的应用

利用水相法制备CdTe量子点,在不同细胞培养基及不同pH值环境中对其进行了稳定性表征,研究了量子点对HeLa细胞增殖抑制率的影响,而后利用耦联转铁蛋白的量子点对HeLa细胞进行了靶向性标记,最后将量子点与葡聚糖耦联,通过透明背脊皮翼视窗观察其在血管内的动态过程。结果表明:合成的量子点发射谱峰值为660nm,在DMEM和M1640细胞培养基中具有良好稳定性,当缓冲液pH值由5升高到13时,量子点荧光强度先升高后下降;量子点浓度为13μg/mL时,HeLa细胞存活率高于80%;耦联转铁蛋白的量子点对HeLa细胞靶向作用明显;可观察到耦联葡聚糖的量子点在小鼠血管中的动态运动。该研究表明合成的量子点可成功用于活体成像。     

CdSe/ZnS和PbSe量子点光纤及光纤放大器研究进展

近年来,纳米晶体(量子点)以及量子点光纤、量子点光纤放大器成为一个研究热点。介绍了CdSe/ZnS和PbSe量子点的光谱特性以及量子点的吸收-辐射截面,表明量子点具有强的吸收和发射。总结了低浓度和较高浓度CdSe/ZnS量子点掺杂光纤、熔融法及溶胶凝胶法制备PbSe量子点光纤材料的最新研究进展,分析了两种方法制备量子点光纤材料的优缺点,概述了PbSe量子点光纤放大器的研究近况,展望了量子点光纤的应用前景。     

面向显示应用的量子点发光器件研究进展

胶体量子点是一种半径接近于激子玻尔半径的新型优质光电材料,其特殊的尺寸效应使其能通过调整尺寸大小实现高纯度的三原色发光、连续可调的光谱以及宽色域。量子点特殊的核壳结构保证了其良好的光/热稳定性;同时,量子点还具有优异的可溶液处理特性,是显示领域研究的热门材料。基于量子点构筑的量子点发光二极管器件也一直被看作是有望取代有机发光二极管的极具潜力的技术。过去的几十年间,量子点发光二极管取得了巨大的成功和快速的发展,被看作是显示领域最具潜力的优质候选材料之一。因此,对量子点发光器件性能进行研究分析并优化,对于加快其商业市场化有很重要的意义。本文从量子点发光器件优化到大面积生产的角度总结了国内外研究者在构筑高效、稳定的面向显示应用的量子点发光器件的研究进展,并分析了其未来发展将面临的困难和挑战。     

量子点-聚合物纳米复合材料的光电器件研究进展

量子点因具有优异的光电特性,近年来备受关注。但量子点的规模化应用因受到其加工工艺及稳定性等因素限制而尚待开发。量子点-聚合物纳米复合材料的出现有效弥补了这一问题,将量子点分散到有机聚合物中形成纳米复合材料,集合量子点与聚合物的各自优势于一体,是解决量子点当前应用问题的一种有效方法,具有显著的发展潜力。文中介绍了量子点的主要制备技术,并在此基础上对量子点-聚合物复合材料的制备方法及其在激光器、发光二极管、光电探测器、量子点电视等光电子器件中的应用进展进行了概述,最后对其在光电器件领域的应用进行了展望。     

自组装InGaN/GaN量子点的研究进展

GaN基量子点的生长及其特性已成为目前Ⅲ-Ⅴ族半导体研究的热点.由于其较强的量子效应,量子点结构的光电器件有望获得比量子阱器件更优异的性能.总结了InGaN/GaN量子点的最新研究进展,从生长模式、发光特性和制造工艺三个方面对InGaN/GaN量子点做了较详细的介绍,并对其在半导体器件的具体应用前景上提出了合理的设想.     

半导体量子点的器件应用

半导体量子点的生长和性质已成为当今研究的热点。以Ｓ－Ｋ生长模式已成功地生长了无缺陷的半导体量子点。由于其较强的量子效应,量子点结构的光电器件和电子器件有望比量子阱结构的器件具有更好的性能。介绍了量子点在光电器件中的一些应用,包括单电子晶体管、激光器和红外探测器等。     

Optical properties of CdTe/(Cd, Mn)Te multiple quantum wells

A review is given of optical properties of the new II-VI strained layer superlattice based on the CdTe/(Cd,Mn)Te heterostructure. Emphasis is given to excitonic phenomena and their contribution to the present but early understanding of electronic characteristics of multiple quantum wells grown by molecular beam epitaxy. The CdTe/ (Cd, Mn)Te system has a number of unique features including its magneto-optical properties, rather weak confinement of hole states, possibility of growth in two different crystalline orientations, and strong influence of interface states.     

量子线红外光子探测器的研究进展

基于半导体量子线子能带间跃迁的量子线红外光子探测器（QRIP）由于其独特的电子性质,具有工作温度较高、信噪比较高、暗电流较低、光谱范围较宽以及垂直入射光响应等特点．对于新型红外探测器的研发而言,QRIP是颇具潜力的候选者之一．通过对近年来部分相关文献的分析介绍,总结和评述了QRIP制备工艺、物理性质、仿真方法等方面的研究进展．     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

金刚石材料的功能特性研究与应用

本文综述了金刚石的功能特性及其近年来在宽禁带半导体、紫外探测器、量子计算机用单光子源、声波材料和电子封装等方面的研究与应用进展,并对金刚石材料在其它功能特性方面的开发与应用前景提出了展望。     

Photoquantum Hall Effect and Light‐Induced Charge Transfer at the Interface of Graphene/InSe Heterostructures

The transfer of electronic charge across the interface of two van der Waals crystals can underpin the operation of a new class of functional devices. Among van der Waals semiconductors, an exciting and rapidly growing development involves the “post‐transition” metal chalcogenide InSe. Here, field effect phototransistors are reported where single layer graphene is capped with n‐type InSe. These device structures combine the photosensitivity of InSe with the unique electrical properties of graphene. It is shown that the light‐induced transfer of charge between InSe and graphene offers an effective method to increase or decrease the carrier density in graphene, causing a change in its resistance that is gate‐controllable and only weakly dependent on temperature. The charge transfer at the InSe/graphene interface is probed by Hall effect and photoconductivity measurmentes and it is demonstrated that light can induce a sign reversal of the quantum Hall voltage and photovoltaic effects in the graphene layer. These findings demonstrate the potential of light‐induced charge transfer in gate‐tunable InSe/graphene phototransistors for optoelectronics and quantum metrology.     

Overview of spin transport electronics in metals

Spintronics has emerged as an exciting and dynamic field of research and development that spans numerous disciplines, including condensed matter physics, materials science, optical science and electrical engineering. The field can be divided roughly into two approaches. The first seeks to utilize the unique properties of ferromagnetic materials for novel functionality in electronic devices by incorporating a magnetic element in a device structure. This approach relies on spin-dependent transport of conduction electrons for integrating a magnetic bit state with charge-based electronic technology. Applications include magnetic field sensors incorporated as read heads and integrated, nonvolatile magnetic random-access memories. The second theme is less conventional and seeks to utilize populations of spin-polarized electrons, or individual magnetic moments, for entirely new paradigms of information processing such as quantum computing. Research in these two areas finds common ground with the study of the optical and/or electronic spin transport properties of conduction electrons. This paper will focus on relatively near term applications, represented by the first, more conventional theme, and on basic principles of spin-polarized transport.     

InP基应变自组装纳米材料及其光电子器件研究进展

半导体低维结构材料,如量子线(点)材料,由于其特殊的电子结构,在新一代光电子、微电子器件中有着重要的应用价值。本文对应变自组装InP基量子线(点)材料的生长制备、光学和电学特性及其在半导体激光器、红外探测器及其他光电子和微电子器件中的应用进行了综述,指出了目前需要改进的一些方面,并提出了一些相应的解决途径。     

Optical transitions in new trends organic materials

The PTCDA (3,4,9,10-perylenetetracarboxylic dianhydride and the NTCDA (1,4,5,8-naphtalenetetracarboxylic dianhydride) are aromatic, stable, planar and highly symmetric with unusual electrical properties. The PTCDA is an organic crystalline semiconductor of particular interest due to its excellent properties and electronic potential that are used in optoelectronic devices, and the NTCDA is monoclinic and its space group is similar to that of PTCDA. Recently, alternate layers of PTCDA and NTCDA were grown forming multiple structures of quantum wells showing a new class of materials with new optic lineal properties. Some have assured that their big utilities would be centered in the construction of diodes and possible guides of waves. We have carried out semi-empirical calculations of electronic structures and optic properties of PTCDA and NTCDA that show us that they are highly orderly polymeric structured semiconductors in a negative load state (charge state=?2).     

纳米金在光学和电化学传感器中的应用

纳米金材料有着特殊的表面效应、量子尺寸效应和宏观量子隧道效应,在电学、磁学、光学和化学性质方面具有常规材料不具备的优越性能.综述了纳米金的制作方法,以及纳米金光学方法和电化学方法应用于生物检测和各种气体、液体检测等方面的研究进展.