半导体纳米材料的性质及化学法制备

着重介绍了半导体纳米粒子的表面效应、量子尺寸效应等基本性质,以及纳米半导体材料的热学、光学和光电化学性质,综述了化学法制备纳米半导体材料的原理和特点。     

量子计算机的基础材料研发动态

介绍了量子计算机的概念及商用机的雏形,报道了量子反常霍尔效应、量子纠缠理论,石墨烯与硅烯等低维材料、纳米器件,以及国家科技政策等方面的发展动态。     

纳米技术在电池中的应用

纳米科学技术是在1～100nm尺寸范围内研究电子、原子、分子的运动规律与特性,它包括纳米材料科学和纳米制造技术等。纳米材料是指晶粒尺寸为1～100nm的超细材料,它们具有量子尺寸效应、小尺寸效应、表面效应、量子隧道效应、表面微结构在纳米尺度上的可调性等特性,因此纳米材料具有特殊的物理、     

半导体纳米晶光电性能的研究进展

综述了近年来国内外纳米晶体光电子性质研究领域某些方面的进展情况,着重介绍了半导体纳米晶在光吸收、光致发光、非线性光学效应和电阻率等方面的独特性能。这些研究表明,对于0—3nm晶体(纳米晶粒处于分散介质中)来说,量子尺寸效应是产生晶体性质突变的主要原因之一。对纳米晶体结构和性能的深入研究,能为光电子材料的发展提供新的途径和思路。     

纳米结构制备技术

随着纳米加工技术的发展,纳米结构器件必将成为将来的集成电路的基础.本文介绍了几种用电子束光刻、反应离子刻蚀方法制备硅量子线、量子点和用电子束光刻、电子束蒸发以及剥离技术制备纳米金属栅的工艺方法;用这种工艺方法在P型SIMOX硅片上成功制造的一种单电子晶体管,在其电流电压-特性上观测到明显的库仑阻塞效应和单电子隧穿效应.     

半导体纳米晶光电性能的研究进展

综述了近年来国内外纳米晶体光电子性质研究领域某些方面的进展情况，着重介绍了半导体纳米晶在光吸收、光致发光、非线性光学效应和电阻率等方面的独特性能。这些研究表明，对于0—3nm晶体(纳米晶粒处于分散介质中)来说，量子尺寸效应是产生晶体性质突变的主要原因之一。对纳米晶体结构和性能的深入研究，能为光电子材料的发展提供新的途径和思路。     

纳米吸波材料的物理实质及研究进展

吸波材料是隐身技术的关键材料,纳米材料由于其特殊的量子尺寸效应和隧道效应等产生的优良的电磁波吸收性能而受到世界各国的重视．本文简单介绍了吸波材料的工作原理,进而阐述了纳米吸波材料吸收电磁波的物理实质．详细介绍了纳米涂敷型吸波材料和纳米结构型吸波材料的研究现状,并对纳米吸波材料的发展趋势进行了展望．     

金属纳米晶存储器件数据保持能力建模与验证

金属纳米晶存储器件具有低功耗、高速读写特性及较高的可靠性,因此近年来在非易失存储器研究领域备受关注.对比分析讨论了量子限制效应与库仑阻塞效应对金属纳米晶费密能级的影响后,发现库仑阻塞效应会严重削弱器件数据保持能力.在综合考虑金属纳米晶量子限制效应和库仑阻塞效应的基础上,提出了金属纳米晶存储器件数据保持能力分析模型,并通过与相关研究文献的实验数据对比分析,证实了本模型的合理性.     

新型纳米材料在微电子技术中的应用探究

针对特征尺寸减小给微电子技术带来的问题,简述了纳米材料的几种量子效应;着重介绍了新型纳米半导体材料(碳纳米管和石墨烯)在后摩尔时代的微电子技术中的应用;探讨了碳纳米管和石墨烯在纳电子器件、集成电路,以及太赫兹技术、量子信息学中的可能应用.     

量子电子器件及其应用

随着半导体芯片的特征尺寸从微米量级向纳米量级挺进,半导体的量子效应现象显现。文章阐述了半导体器件中的量子尺寸效应、隧道效应、干涉效应等量子效应的种类以及利用这些量子效应制作的量子点器件、谐振隧穿器件和单电子器件三大种类量子电子器件。介绍了各类量子电子器件的原理以及它们具有超高速、超高频、高集成度、低功耗和高特征温度等优越特性,并着重介绍了各类量子电子器件的制造方法。在此基础上,指出了量子电子器件的应用及发展前景。     

金纳米颗粒增强富硅氮化硅发光特性的研究

采用时域有限差分(FDTD)方法,对Au纳米颗粒的尺寸和形貌对于其光学特性的影响进行了系统的理论研究。通过采用等离子体增强化学气相沉积(PECVD)、晶化处理、电子束蒸发和高温退火等工艺,制备基于局域表面等离子共振(LSPR)效应的富硅氮化硅发光芯片。利用拉曼光谱仪、扫描电子显微镜(SEM)、奥林巴斯显微镜等对不同结构Au纳米颗粒富硅氮化硅发光器件的特性进行了表征。研究表明,通过对Au纳米颗粒的大小、形状和分布合理优化,富硅氮化硅芯片的发光强度在570nm波长附近提升了7倍,增强峰的位置红移了10nm。     

基于C60结构的金纳米粒子合成物的非线性折射与光限幅

利用调Q倍频ns/psNd∶YAG激光脉冲 ,使用Z 扫描技术和光限幅实验研究了新型的基于富勒烯C60 结构体系的金纳米粒子合成物的非线性折射和光限幅特性。实验结果表明材料的非线性折射主要起源于材料中的金纳米粒子所产生的表面等离子体 ,材料的光限幅特性好于C60 甲苯溶液 ,并对限幅机理进行了讨论。     

Optical properties of wurtzite GaN/AlN quantum dots grown on non-polar planes: The effect of stacking faults in the reduction of the internal electric field

The optical emission of non-polar GaN/AlN quantum dots has been investigated. The presence of stacking faults inside these quantum dots is evidenced in the dependence of the photoluminescence with temperature and excitation power. A theoretical model for the electronic structure and optical properties of non-polar quantum dots, taking into account their realistic shapes, is presented which predicts a substantial reduction of the internal electric field but a persisting quantum confined Stark effect, comparable to that of polar GaN/AlN quantum dots. Modeling the effect of a 3 monolayer stacking fault inside the quantum dot, which acts as zinc-blende inclusion into the wurtzite matrix, results in an additional 30% reduction of the internal electric field and gives a better account of the observed optical features.     

A photon echo in a system of ensemble qubits that are selectively radiated by short laser pulses

Equations of quantum computing in a system of two ensemble qubits are solved. The qubits are spherical nanoparticles activated by two-level atoms. It is proved that a photon echo may occur during quantum computations in an optical quantum computer when the ensemble qubits are selectively excited by short optical pulses. The photon echo phenomenon is caused by time reversal of oscillations of induced dipole moments of the qubits. It is shown that this effect can be observed in the case of interference of oscillating dipoles in the wave zone.     

Reprint of: Optical properties of wurtzite GaN/AlN quantum dots grown on non-polar planes: The effect of stacking faults in the reduction of the internal electric field

The optical emission of non-polar GaN/AlN quantum dots has been investigated. The presence of stacking faults inside these quantum dots is evidenced in the dependence of the photoluminescence with temperature and excitation power. A theoretical model for the electronic structure and optical properties of non-polar quantum dots, taking into account their realistic shapes, is presented which predicts a substantial reduction of the internal electric field but a persisting quantum confined Stark effect, comparable to that of polar GaN/AlN quantum dots. Modeling the effect of a 3 monolayer stacking fault inside the quantum dot, which acts as zinc-blende inclusion into the wurtzite matrix, results in an additional 30% reduction of the internal electric field and gives a better account of the observed optical features.     

Direct Assembly of Vertically Oriented,Gold Nanorod Arrays

Although many nanoscale materials such as quantum dots and metallic nanocrystals exhibit size dependent optical properties, it has been difficult to incorporate them into optical or electronic devices because there are currently no methods for precise, large-scale deposition of single nanocrystals. Of particular interest is the need to control the orientation of single nanocrystals since the optical properties are usually strongly anisotropic. Here a method based on electrophoretic deposition (EPD) is reported to precisely assemble vertically oriented, single gold nanorods. It is demonstrated that the orientation of gold nanorods during deposition is controlled by the electric dipole moment induced along the rod by the electric field. Dissipative particle dynamics simulations indicate that the magnitude of this dipole moment is dominated by the polarizability of the solution phase electric double layer around the nanorod. The resulting vertical gold nanorod arrays exhibit reflected colors due to selective excitation of the transverse surface plasmon mode. The EPD method allows assembly of arrays with a density of over one million, visually resolvable, vertical nanorods per square millimeter.     

Self‐Assembly of Mechanoplasmonic Bacterial Cellulose–Metal Nanoparticle Composites

Nanocomposites of metal nanoparticles (NPs) and bacterial nanocellulose (BC) enable fabrication of soft and biocompatible materials for optical, catalytic, electronic, and biomedical applications. Current BC–NP nanocomposites are typically prepared by in situ synthesis of the NPs or electrostatic adsorption of surface functionalized NPs, which limits possibilities to control and tune NP size, shape, concentration, and surface chemistry and influences the properties and performance of the materials. Here a self‐assembly strategy is described for fabrication of complex and well‐defined BC–NP composites using colloidal gold and silver NPs of different sizes, shapes, and concentrations. The self‐assembly process results in nanocomposites with distinct biophysical and optical properties. In addition to antibacterial materials and materials with excellent senor performance, materials with unique mechanoplasmonic properties are developed. The homogenous incorporation of plasmonic gold NPs in the BC enables extensive modulation of the optical properties by mechanical stimuli. Compression gives rise to near‐field coupling between adsorbed NPs, resulting in tunable spectral variations and enhanced broadband absorption that amplify both nonlinear optical and thermoplasmonic effects and enables novel biosensing strategies.     

Nonlinear optical response of planar and spherical CdSe nanocrystals

The nonlinear optical response of a colloidal solution of planar CdSe semiconductor nanocrystals (nanoplatelets) is studied for the first time. The nonlinear optical response of these nanoparticles is compared to that of spherical CdSe nanocrystals (quantum dots). The photoinduced nonlinearity is attributed to the optical generation of long-lived charge carriers in the nanoobjects under study. It is shown that, upon the exposure of a cell with the solution of nanoparticles to focused continuous-wave (cw) laser radiation with a wavelength of 473 nm, the nonlinear optical responses of CdSe nanoplatelets and quantum dots are somewhat different at identical optical densities at the above-indicated wavelength. The differences are supposedly associated with a higher diffusion rate of spherical nanoparticles in the solution because of their smaller size compared to that of nanoplatelets.     

Quantum size dependent optical nutation in a core-shell CdSe/ZnS quantum dot

The energy eigenvalues and eigenfunctions have been obtained for a core-shell CdSe/ZnS quantum dot structure under effective-mass approximation. The electric transition dipole moment is calculated for the 1s-2s electronic transition. The optical nutation signal of the transition of electrons has been calculated numerically based on optical Bloch equations. Particularly, we have investigated the quantum size, the core's radius and the shell's thickness, dependent optical nutation. It is shown from calculation results that the optical nutation signal is sensitive to the size and structure change. And the reasons for the variation of the Rabi frequency have been discussed based on the theory of the quantum size confined effect (QSCE).     

金纳米微粒的光学性质及其在生物成像和光热疗法中的应用

作为生物探针,纳米微粒以其独特的光学性质,易控的表面化学能力,在基于生物成像和诊断的分子生物学和医学领域中引起越来越广泛的关注.贵金属,尤其是金纳米微粒,由于其表面等离子体共振(SPR)等强吸收和发光特性,在生物组织成像,癌症的诊断和治疗中存在着巨大的应用前景.结合配体的金纳米微粒能够特异性地标记癌症细胞上的受体,并提供特定分子的特有信息,进行生物成像和癌症检测.另外,金纳米微粒能够有效地吸收光能量进行局部加热,导致蛋白质变性,并致细胞死亡.主要回顾各种不同尺寸和形状的金纳米微粒的光学特性,以及选择性标记的金纳米微粒在生物成像,癌症诊断和光热疗法中的研究进展.