单元素半导体量子点制备及其光致发光性能的研究进展

单元素半导体量子点的制备成功使光电集成成为可能.介绍了单元素半导体量子点的制备方法,包括射频磁控溅射技术、硅离子注入技术、化学气相沉积法、溶胶-凝胶法等;并且介绍了单元素半导体量子点的发光机理模型,包括量子限制效应模型、与氧有关的缺陷发光、量子限制效应-发光中心复合发光和界面层中的激子效应发光等;另外对单元素半导体量子点的发展前景进行了展望.     

Ⅱ-Ⅵ族化合物半导体量子结构材料和器件的研究与发展

简要介绍了量子结构材料与器件中的基本概念,重点介绍了量子结构的定义和量子尺寸效应的能带裁剪工程。以II-VI族化合物半导体为例,介绍了量子尺寸效应对于激子束缚能的影响。以此为基础,综述了II-VI族化合物半导体量子阱、量子点等量子结构材料以及量子结构器件在光电探测、发光器件与太阳能电池领域的研究现状,并总结了II-VI族化合物半导体量子结构材料与器件的发展趋势。     

Ⅱ-Ⅵ族化合物半导体量子结构材料和器件的研究与发展

简要介绍了量子结构材料与器件中的基本概念,重点介绍了量子结构的定义和量子尺寸效应的能带裁剪工程.以Ⅱ-Ⅵ族化合物半导体为例,介绍了量子尺寸效应对于激子束缚能的影响.以此为基础,综述了Ⅱ-Ⅵ族化合物半导体量子阱、量子点等量子结构材料以及量子结构器件在光电探测、发光器件与太阳能电池领域的研究现状,并总结了Ⅱ-Ⅵ族化合物半导...     

超声化学法PbSe和PbS量子点制备技术的研究进展

半导体量子点材料因具有尺寸效应和独特的光谱效应而受到人们的重视.因此,如何有效地制备符合需要的量子点已成为近年来研究的一个热点.对各种超声化学法制备PbS、PbSe进行探讨,介绍了其实验步骤,比较了其结果,讨论分析了超声波法制备量子点的优势和不足,并提出了一些在原有基础上可以改进的地方,最后展望了纳米材料的应用前景.     

玻璃中的非线性光学原理及材料

本文简要介绍了玻璃中产生非线性光学效应的基本原理及其应用,并介绍了均质玻璃、含有机化合物及含半导体量子点玻璃的非线性光学性能、应用前景和研究动态。     

单分散性硫族化合物半导体量子点的制备与表征

硫族半导体化合物大多具有直接能带结构,是良好的光电功能材料,其量子点具有典型的量子效应.介绍了单分散量子点的无机成核/有机包裹的合成方法,通过尺寸选择性沉淀可以得到单分散的量子点;TEM、XRDUV-Vis吸收谱对硫族量子点的表征.     

半导体量子点/聚合物纳米复合材料研究进展

半导体量子点/聚合物纳米复合材料是在分子尺度上形成的先进光电功能材料,其综合了半导体和聚合物材料的各自优点,并呈现出独特的电学、光学和光电子学等特性.根据聚合物中掺杂纳米半导体量子点材料的种类不同,对半导体量子点/聚合物纳米复合材料的制备、分类、器件结构与特性和研究进展进行了概要评述,并展望了其发展趋势.     

InAs/GaAs自组织量子点的可控分子束外延生长及其新型光电器件研究北大核心CSCD

半导体量子点因其具有类原子的分立能级结构,可在三维方向上对载流子运动进行束缚,因此被认为是光发射器件(激光器、量子光源等)极具前景的有源物质之一。其器件的性能强烈依赖于量子点材料的品质、光场与量子点偶极子场的有效相互作用等。本文将从半导体InAs/GaAs自组织量子点的可控分子束外延生长调控技术出发,进一步探讨应用于光通信、片上光互联领域的量子点激光器,以及应用于光量子信息领域的高品质量子光源器件。     

胶体化学法合成半导体量子点的研究进展

介绍了制备半导体量子点的3种方法,包括光刻、自组织生长和胶体化学方法.简要比较了3种方法,详细讨论了用胶体化学法合成半导体量子点.胶体量子点具有一些优异的性能,有着广泛的应用,列举了胶体量子点的一些独特应用.     

CdS半导体纳米晶的生长及其光谱研究

用玻璃沉淀技术制备了含过饱和CdS的玻璃固溶体,在一定条件下晶化处理使其长出CdS量子点,并采用了X射线衍射、高分辨扫描电镜、光吸收谱和荧光发光光谱等测试手段分析其性能,结果表明经过晶化处理可以在玻璃中长出CdS量子点,尺寸大约为10～25nm,吸收谱中出现明显的红移现象,反映出量子点的量子限域效应,荧光发光图谱中可以看出量子点发光主要由带隙发光和表面缺陷态发光组成,提高热处理温度可以改善晶粒的完整性.     

Electronic structure and optical property of semiconductor nanocrystallites

Semiconductor nanostructures show many special physical properties associated with quantum confinement effects, and have many applications in the opto-electronic and microelectronic fields. However, it is difficult to calculate their electronic states by the ordinary plane wave or linear combination of atomic orbital methods. In this paper, we review some of our works in this field, including semiconductor clusters, self-assembled quantum dots, and diluted magnetic semiconductor quantum dots. In semiconductor clusters we introduce energy bands and effective-mass Hamiltonian of wurtzite structure semiconductors, electronic structures and optical properties of spherical clusters, ellipsoidal clusters, and nanowires. In self-assembled quantum dots we introduce electronic structures and transport properties of quantum rings and quantum dots, and resonant tunneling of 3-dimensional quantum dots. In diluted magnetic semiconductor quantum dots we introduce magnetic-optical properties, and magnetic field tuning of the effective g factor in a diluted magnetic semiconductor quantum dot.     

镶嵌在介质层中纳米晶的单电子能级的精确求解

假设镶嵌在介质层(如SiO2、SiC)中的纳米晶(如Si、Ge、Sn)为球形量子点,考虑到电子在纳米晶和介质层中的有效质量差异,对镶嵌在介质层中单电子的所有束缚态的能量和波函数进行精确求解,分析了量子点半径、势垒高度、电子有效质量等对能级的影响。计算结果表明,量子限制效应随着量子点半径的减小而急剧增强,不同材料电子的有效质量对电子能级也有重要影响。Sn纳米晶的半径为22nm左右,Ge的半径和Si的半径分别约为10nm和7nm时,能观察到较为明显的量子限制效应。本模型提出的计算方法快速而准确,并适用于任意尺寸、任意势垒和任意材料的球方势阱量子点系统。     

硫化铜量子点的研究进展

硫化铜量子点作为一种p型半导体纳米晶,具有很强的表面等离子体共振效应、低的毒性以及独特的光学和电学性能,在光催化、生物技术、光电转换材料领域受到了极大关注。由于单分散的硫化铜量子点的制备过程复杂,效率较低,并且纯的硫化铜量子点电导率较低,这极大地限制了其在能量存储器件方面的应用。此外,由于硫化铜量子点复杂的能带结构和独特的p型半导体特性,针对硫化铜量子点的光学性能调控尚不成熟。基于此,本文综述了硫化铜量子点在制备方面的研究现状与取得的进展,介绍了硫化铜量子点的能带结构、晶体结构,及其在量子点敏化太阳能电池、光催化降解污染物、肿瘤细胞诊断与治疗等方面的研究进展,并对硫化铜量子点或Cu系量子点更进一步的研究、开发应用提出了几点建议。     

Energetic pinning of magnetic impurity levels in quantum-confined semiconductors

Donor- and acceptor-type (D/A) impurities play central roles in controlling the physical properties of semiconductors. With continued miniaturization of information processing devices, the relationship between quantum confinement and D/A ionization energies becomes increasingly important. Here, we provide direct spectroscopic evidence that impurity D/A levels in doped semiconductor nanostructures are energetically pinned, resulting in variations in D/A binding energies with increasing quantum confinement. Using magnetic circular dichroism spectroscopy, the donor binding energies of Co2+ ions in colloidal ZnSe quantum dots have been measured as a function of quantum confinement and analyzed in conjunction with ab initio density functional theory calculations. The resulting experimental demonstration of pinned impurity levels in quantum dots has far-reaching implications for physical phenomena involving impurity-carrier interactions in doped semiconductor nanostructures, including in the emerging field of semiconductor spintronics where magnetic-dopant-carrier exchange interactions define the functionally relevant properties of diluted magnetic semiconductors.     

Optoelectronic and nonlinear optical processes in low dimensional semiconductors

Spatial confinement of quantum excitations on their characteristic wavelength scale in low dimensional materials offers unique possibilities to engineer the electronic structure and thereby control their physical properties by way of simple manipulation of geometrical parameters. This has led to an overwhelming interest in quasi-zero dimensional semiconductors or quantum dots as tunable materials for multitude of exciting applications in optoelectronic and nonlinear optical devices and quantum information processing. Large nonlinear optical response and high luminescence quantum yield expected in these systems is a consequence of huge enhancement of transition probabilities ensuing from quantum confinement. High quantum efficiency of photoluminescence, however, is not usually realized in the case of bare semiconductor nanoparticles owing to the presence of surface states. In this talk, I will focus on the role of quantum confinement and surface states in ascertaining nonlinear optical and optoelectronic properties of II–VI semiconductor quantum dots and their nanocomposites. I will also discuss the influence of nonlinear optical processes on their optoelectronic characteristics.     

Site‐Controlled Single‐Photon Emitters Fabricated by Near‐Field Illumination

Many of the most advanced applications of semiconductor quantum dots (QDs) in quantum information technology require a fine control of the QDs' position and confinement potential, which cannot be achieved with conventional growth techniques. Here, a novel and versatile approach for the fabrication of site‐controlled QDs is presented. Hydrogen incorporation in GaAsN results in the formation of N–2H and N–2H–H complexes, which neutralize all the effects of N on GaAs, including the N‐induced large reduction of the bandgap energy. Starting from a fully hydrogenated GaAs/GaAsN:H/GaAs quantum well, the N? H bonds located within the light spot generated by a scanning near‐field optical microscope tip are broken, thus obtaining site‐controlled GaAsN QDs surrounded by a barrier of GaAsN:H (laterally) and GaAs (above and below). By adjusting the laser power density and exposure time, the optical properties of the QDs can be finely controlled and optimized, tuning the quantum confinement energy over more than 100 meV and resulting in the observation of single‐photon emission from both the exciton and biexciton recombinations. This novel fabrication technique reaches a position accuracy <100 nm and it can easily be applied to the realization of more complex nanostructures.     

硫硒化镉微晶玻璃制备和非线性光学性质研究

具有明显量子尺寸效应和较大三阶非线性光学效应的CdSxSe1-x(O相似文献