原位电子束诱导沉积制备碳纳米结构

以多壁碳纳米管为基本材料,利用电子束诱导沉积的方法进行了纳米结构加工、修饰研究.电子束诱导沉积实现了二个碳纳米管端部之间的牢固焊接,实现了纳米材料间的几乎无损伤连接.原位测量表明多壁碳纳米管间的连接为欧姆接触.进一步对碳纳米管施加外电场可以使端部碳原子间的π键打开,外部碳原子经电子束诱导沉积在碳纳米管的端部,并定向生长成非晶态碳纳米线.由于碳纳米管和纳米线结合处的.键作为绝缘界面,形成了电子输运的势垒,所得到的碳纳米管-纳米线复合结构具有整流特性.利用电子显微镜进行纳米材料的结构加工、修饰,具有选择位置精确、可实时监测、对纳米材料几乎无损伤、重复性和可靠性高,以及加工尺度可人为控制的特点.     

关于准一维ZnSe纳米结构的合成与应用

硒化锌是Ⅱ-Ⅵ族中重要的宽禁带半导体材料,其禁带宽度为2.7 eV,是理想的蓝光探测器材料。准一维ZnSe纳米结构的合成有多种,如纳米带、纳米线、纳米棒等。由于纳米材料与薄膜材料相比具有表面积大、量子效应等独特的物理及化学特性,使得基于纳米材料的纳米器件在过去的几年内被广泛的制备与研究。目前准一维ZnSe纳米材料已经制备出多种纳米器件,文中将对ZnSe纳米结构的合成以及应用作介绍。     

运用精确电压衬度像技术实现精确定位的原位电子束纳米刻蚀：制造具有悬挂纳米线结构的纳米器件

本文演示了运用精确电压衬度像技术实现原位电子束纳米刻蚀技术的精确定位,并运用该技术制作成具有悬挂结构的纳米开关。通过运用精确电压衬度像定位技术,能够很好地控制偏转电极的定位,误差可减少到大约10nm。通过该技术,不用通过任何刻蚀过程只运用一次电子束纳米刻蚀,便可实现将分散的纳米线夹在两个电阻层中间形成悬挂结构。在原位电子束刻蚀的整个过程中,无需移动样品台从而消除了样品台的移动误差。因此,整个过程中不需要高精确的激光台和定位标记,从而简化了传统的电子束纳米刻蚀工艺。通过该方法制作的纳米开关随着施加电压的改变很好地实现了闭合和断开的状态。这种简化的过程提供了一种简单、低成本、快速的通过改装过的场发射扫描电子显微镜（FESEM）来制作纳米线悬挂结构的方法,并可运用该技术进一步制造多层结构和特殊的纳米器件。     

钛酸铅超细纳米晶及纳米线的制备与结构表征

近来，一维纳米材料吸引了物理学、材料学和化学界的广泛关注，成为纳米材料研究的热点。纳米线是物质在纳米尺度上的一种特殊结构，其优异的光学、电学和力学性能，在纳米器件的应用领域极具发展前景。纳米线的制备技术及物性的测量是材料在纳米原型器件制作和应用的关键，不断探索低维纳米材料的制备新技术，合成出多种材料的纳米线具有重要意义。     

Towards property nanom easurements by in- situTEM- presentand prospects

纳米材料的研究无论是在基础科学还是在应用技术上都面临着许多新的挑战。纳米材料的性能极大地取决于它们的尺寸和形状。测量大面积或大量的纳米材料所得的性能是整个样品的平均值,因此,单个纳米颗粒或单根纳米管的不寻常的特性就被掩盖了。测量由原子结构所决定的单一纳米结构的性能是纳米科学的一个基本方向。对现有的测试技术和试验方法来说,表征单一纳米颗粒纳米管纳米纤维的性能是一难题。首先,因为它的尺寸(直径和长度)相当小,现有的实验手段不适用,像纤维类材料的弹性和蠕变实验,要求样品的尺寸足够大,能够固定在试样台的夹具上,这种简单易行的方法对于纳米结构的纤维则不适用。其次,纳米结构的小尺寸使得手工操作相当困难,需要有一种针对单一纳米结构设计的专门测试技术来进行操作。因此,为了准确测量单一纳米结构的性能,开发新的方法和手段是十分必要的。我们的工作目的就在于此。本文综述了我们在开拓和发展原位透射电子显微学在表征纳米材料的力学,电学和热力学性能方面的现状和展望。该研究的焦点集中在如何定量测试一微结构已知的单一纳米结构的物理性能,从而实现了表征结构—性能关联中的一对一关系,开拓了原位透射电子显微镜在纳米材料科学研究中的新方向和新天地。     

高分辨LEO 1530 VP扫描电镜在纳米技术研究中的应用

随着纳米技术和纳米产业化的进展、研究和制备纳米材料、纳米结构组装和纳米加工的尺寸越来越小，纳米级图像分析，尺寸测量和微区成分检测已成为纳米技术工作的主要内容之一。本文通过我们实际工作，概述了高分辨率LEO1530VP扫描电镜和EDAX能谱在纳米技术研制工作中的重要作用。实验表明LEO1530VP扫描电镜的超高分辨性能和可变压力模式下能直接观测绝缘样品的特点，在纳米技术各研究领域中，具有广泛的应用前景。     

名词释义——准一维纳米材料

准一维纳米材料是指在两维方向上为纳米尺度，长度为宏观尺度的新型纳米材料。如纳米棒、纳米线、半导体纳米量子线、纳米线阵列等都属于准一维纳米材料。这些新型材料的实验研究，为进一步研究纳米结构和准一维纳米材料的性能，建立准一维纳米材料的新理论和推进它们在纳米结构器件中的应用奠定了基础。     

半导体锗纳米团簇和纳米层的生成与结构研究

我们在硅锗合金衬底上采用氧化等制膜方式生成零维和二维的纳米结构样品，用高精度椭偏仪(HPE)、卢瑟福背散射谱仪(RBS)和高分辨率扫描透射电子显微镜(HR-STEM)测量样品的纳米结构，并采用美国威思康新州立大学开发的Rump模拟软件对卢瑟福背散射谱(RBS)中的CHANNEL谱和RANDoM谱分别进行精细结构模拟，测量并计算出纳米氧化层与锗的纳米薄膜结构分布，并且反馈控制加工过程，优化硅锗半导体材料纳米结构样品的加工条件。我们测量出样品横断面锗纳米团簇和纳米层的PL发光谱。我们在硅锗合金的氧化层表面中首次发现纳米锗量子点组成的几个纳米厚的盖帽膜结构，我们首次提出的生成硅锗纳米结构的优化加工条件的氧化时间和氧化温度匹配公式的理论模型与实验结果拟合得很好。     

纳米级性能微测量中的原位透射电子显微学的现状和展望

纳米材料的研究无论是在基础科学还是在应用技术上都面临着许多新的挑战。纳米材料的性能极大地取决于它们的尺寸和形状。测量大面积或大量的纳米材料所得的性能是整个样品的平均值，因此，单个纳米颗粒或单根纳米管的不寻常的特性就被掩盖了。测量由原子结构所决定的单一纳米结构的性能是纳米科学的一个基本方向。对现有的测试技术和试验方法来说，表征单一纳米颗粒／纳米管／纳米纤维的性能是一难题。首先，因为它的尺寸（直径和长     

电子断层成像技术在两种纳米材料中的应用

本文通过使用电子断层成像技术,分别对纳米金样品和纳米囊泡药物两种材料进行多角度成像研究,发现纳米金样品为圆盘状,并没有棒状结构,同时还测量了纳米金盘的厚度。纳米囊泡拟包含药物为膜状结构而非针状或棒状。多角度成像排除了二维电镜图片的假象,显示电子断层成像技术在纳米材料的应用前景。     

Electron microscopy characterization of airborne micro- and nanoparticulate matter

The aim of this work was to offer a state-of-the-art critical survey for characterizing airborne nano- and microparticles by means of electron microscopy (EM) techniques and to highlight advantages and limits of different possible operation modes. Procedures of collection and sample preparation are revisited and improved to analyse airborne particles deposited on filtering membranes by using various sampling methods. Three kinds of electron microscopes are used to this end: scanning electron microscope (SEM), field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM). Following and extending previous studies, we optimized procedures by varying both the sample collection/preparation and the operational parameters of the microscopes. In particular, we diversified the sampling methods applied, using ad hoc filters as well as common filters for standard gravimetric measures. This approach enabled us to achieve a simple and clean procedure allowing direct SEM or TEM observation of the collected particulate matter.     

Si/Ge复合纳米结构的制备及表征

以Si和GeO2为原料,通过简单直接的热蒸发法在衬底的不同温度区域上得到了章鱼状、羽毛球状、拖把状等不同形貌的Si/Ge/O复合纳米结构。利用扫描电镜（SEM）研究了不同衬底区域纳米结构的形态,结合透射电镜（TEM）的明场像和扫描透射（STEM）模式下能谱的面扫描,系统地研究了不同形貌纳米结构的成分分布,并对生长过程进行了探讨。     

材料变形过程中的原位电子背散射衍射(in-situ EBSD)分析

本文介绍一套既具备电子背散射衍射（EBSD）,又具备应力加载功能的分析测试方法,简称原位EBSD。采用该系统能实现对拉伸、压缩、弯曲及剪切变形过程中材料的微观组织演变进行原位跟踪观察;可以分析材料在变形过程中的组织演变过程,获得组织演变的连续性信息,从而对研究材料变形过程中的机理及物理本质提供有力的实验依据。本文还以原位压缩过程中纯镁的微观组织演变的测试与分析为例,说明原位EBSD系统使用方法。     

Shell-Isolated Plasmonic Nanostructures for Biosensing,Catalysis, and Advanced Nanoelectronics

Shell-isolated nanostructures, consisting of an inert shell and a plasmonic core, have recently been intensively explored for biosensing, catalysis, and nanoelectronics applications owing to their functional shells and unique plasmonic properties. Such designer shell-isolated plasmonic nanostructures possess the potential to improve the detectability of biosensors and provide powerful platforms to explore in-depth plasmon enhancement principles and finally boost significantly their photo(electro)catalytic efficiency. In addition, such structural optimization and interface nanoengineering promote solid developments of advanced nanoelectronics toward real applications, revealing new electron transport mechanisms and enabling exploration of new functional and integrated optoelectronic devices. In this overview, the state-of-the-art progresses of shell-isolated plasmonic nanostructures (SHIPNSs) in the field of biosensing, photo(electro)catalysis, and nanoelectronics is summarized, focusing on the superiority of the core–shell materials in exploration of biosensing, catalytic enhancement mechanisms, and electron transport principles. A brief overview of synthetic methods is introduced, and then the significant importance of shell-isolated nanomaterials in fabrication and promising direction for future development and challenges are discussed.     

Nanomaterials via Laser Ablation/Irradiation in Liquid: A Review

Laser ablation of solid targets in the liquid medium can be realized to fabricate nanostructures with various compositions (metals, alloys, oxides, carbides, hydroxides, etc.) and morphologies (nanoparticles, nanocubes, nanorods, nanocomposites, etc.). At the same time, the post laser irradiation of suspended nanomaterials can be applied to further modify their size, shape, and composition. Such fabrication and modification of nanomaterials in liquid based on laser irradiation has become a rapidly growing field. Compared to other, typically chemical, methods, laser ablation/irradiation in liquid (LAL) is a simple and “green” technique that normally operates in water or organic liquids under ambient conditions. Recently, the LAL has been elaborately developed to prepare a series of nanomaterials with special morphologies, microstructures and phases, and to achieve one‐step formation of various functionalized nanostructures in the pursuit of novel properties and applications in optics, display, detection, and biological fields. The formation mechanisms and synthetic strategies based on LAL are systematically analyzed and the reported nanostructures derived from the unique characteristics of LAL are highlighted along with a review of their applications and future challenges.     

液相激光烧蚀法制备纳米材料的研究进展

液相激光烧蚀方法,主要是利用激光与液态介质相互作用、产生局域高温高压非平衡过程而获得纳米材料的方法,能够有效合成常规手段无法合成的新型纳米材料。阐述了液相激光烧蚀法(包括非反应性液相激光烧蚀和反应性液相激光烧蚀)制备纳米材料的基本原理和国内外研究现状,并指出这一领域存在的主要问题与发展方向。     

Probing Local Electronic Transitions in Organic Semiconductors through Energy‐Loss Spectrum Imaging in the Transmission Electron Microscope

Improving the performance of organic electronic devices depends on exploiting the complex nanostructures formed in the active layer. Current imaging methods based on transmission electron microscopy provide limited chemical sensitivity, and thus the application to materials with compositionally similar phases or complicated multicomponent systems is challenging. Here, it is demonstrated that monochromated transmission electron microscopes can generate contrast in organic thin films based on differences in the valence electronic structure at energy losses below 10 eV. In this energy range, electronic fingerprints corresponding to interband excitations in organic semiconductors can be utilized to generate significant spectral contrast between phases. Based on differences in chemical bonding of organic materials, high‐contrast images are thus obtained revealing the phase separation in polymer/fullerene mixtures. By applying principal component analysis to the spectroscopic image series, further details about phase compositions and local electronic transitions in the active layer of organic semiconductor mixtures can be explored.     

Recent progress of efficient flexible solar cells based on nanostructures

Flexible solar cells are important photovoltaics (PV) technologies due to the reduced processing temperature,less ma-terial consumption and mechanical flexibility,thus they have promising applications for portable devices and building-integ-rated applications.However,the efficient harvesting of photons is the core hindrance towards efficient,flexible PV.Light man-agement by nanostructures and nanomaterials has opened new pathways for sufficient solar energy harvesting.Nanostruc-tures on top surfaces provide an efficient pathway for the propagation of light.Aside from suppressing incident light reflection,micro-structured back-reflectors reduce transmission via multiple reflections.Nanostructures themselves can be the absorber lay-er.Photovoltaics based on high-crystallinity nanostructured light absorbers demonstrate enhanced power conversion effi-ciency (PCE) and excellent mechanical flexibility.To acquire a deep understanding of the impacts of nanostructures,herein,a concise overview of the recent development in the design and application of nanostructures and nanomaterials for photovolta-ics is summarized.     

Synthesis,field emission and optical properties of ZnSe nanobelts,nanorods and nanocones by hydrothermal method

ZnSe nanostructures, such as nanobelts, nanorods and nanocones, were successfully synthesized on Zn foils via a hydrothermal method using EDTA as soft template at low temperature. EDTA played a significant role on the morphology of ZnSe nanomaterials. X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and energy dispersive spectrometer (EDS) were carried out to characterize the microstructures and chemical compositions of the as-synthesized ZnSe samples. XRD patterns indicated that the as-synthesized ZnSe samples belonged to a cubic zinc blende structure. SEM observation obviously showed that the nanocones had very sharp tips compared to nanorods and nanobelts. The field emission (FE) measurement showed that the as-synthesized ZnSe nanocones had a lower turn-on field of ~1.6 V μm⁻¹ at the current density of 10 μA cm⁻². A high field enhancement factor of ~4514 was achieved for the ZnSe nanocones. The superior field emission properties were probably attributed to the sharp tips of the ZnSe nanocones. Room temperature photoluminescence (PL) spectroscopy of the ZnSe nanostructures showed a wide band emission from blue light to orange light. The as-prepared ZnSe nanomaterials have promising applications in optoelectronic devices. A possible formation mechanism of ZnSe nanobelts, nanorods and nanocones was also proposed and discussed.