一维硅纳米材料形貌的研究

一维硅纳米材料是重要的纳米电子器件材料,由于其形貌不同,导致的电学等特性也不相同,因此一维硅纳米材料的形貌是重要的研究内容之一.一维硅纳米结构包括纳米线、纳米带及纳米管等,同种一维硅纳米材料由于制备方法不同其形貌也不相同.评述了一维硅纳米材料的形貌及其制备方法.     

一维锗酸盐纳米材料的合成及应用

一维锗酸盐纳米材料具有良好的光催化、传感、电学及光学特性,在纳米光催化、纳米光学、纳米电学及传感领域具有很好的应用潜力。本文综述了一维锗酸盐纳米材料的合成、性能及应用的研究现状与最新进展情况,重点讨论了利用热蒸发、水热法、化学气相沉积等方法合成锗酸盐纳米线、纳米棒与纳米带以及一维锗酸盐纳米材料在磁性器件、电化学传感器、光催化及锂离子电池方面的应用进展情况,同时指出了一维锗酸盐纳米材料的发展方向。     

一维硅纳米材料的研究进展

作为微电子领域最重要的半导体材料,硅的一维纳米结构在器件组装、纳米尺寸磁性器件、光电子等领域具有重要的作用,已经成为国际上材料科学研究的一个热点.从制备方法、应用前景等方面综述了国际上关于纳米硅丝和纳米硅管的研究进展,并提出今后的研究方向.     

微应变诱导各向异性硅纳米晶形成及其光学特性

通过磁控溅射技术制备了非晶态富硅的碳化硅锗(Si_(1-x-y)Ge_xC_y)薄膜,经过后续高温热处理,形成各向异性硅纳米晶,其微结构和光学特性由高分辨电镜、光致发光及光吸收实验进行表征,研究了各向异性应变对硅纳米晶形态和光学特性的影响,阐述了各向异性硅纳米晶的形成机理。研究表明,在各向异性应变能的诱导下硅纳米晶沿着〈002〉、〈113〉和〈220〉取向择优生长,形成具有多形态的硅纳米晶,显著改变了其能级结构,在2.57eV和2.64eV的位置硅纳米晶存在PL发射光谱,光吸收波段明显增加,可以同时吸收从红外到紫外(2.57eV,1.89eV,1.2eV和0.96eV)的光子,且光吸收范围随硅锗(RS/G)比例可调,故有望提高光伏电池的光量子产额。     

原位生长纳米炭纤维/硅复合材料及其储锂性能

采用催化化学气相沉积法在微米硅颗粒表面原位生长纳米炭纤维得到纳米炭纤维/硅复合材料.利用SEM,TEM和XRD表征了复合材料的表面形态和微观结构,并考察了其作为锂离子电池负极材料的循环性能.电化学测试表明:与纳米纤维/硅机械混合物相比,原位生长纳米炭纤维/硅复合材料具有更高的可逆容量(1042mAh/g)和更好的循环稳定性.根据SEM和交流阻抗分析结果,分析了纳米炭纤维/硅复合材料在充放电过程中的结构演变机制,其优异的电化学性能主要来源于原位生长纳米炭纤维与硅颗粒之间良好的接触性能.     

纳米二氧化钛/壳聚糖一维纳米复合材料制备及结构分析

无机材料纳米二氧化钛和生物材料壳聚糖在抗菌方面都有比较广泛的应用,但是二者的抑菌机理有所差别,各自在应用中也存在一定缺点和局限性.为改善性能,扩展应用,提出纳米二氧化钛/壳聚糖一维复合的概念,制备了纳米二氧化钛/壳聚糖一维纳米复合材料,并利用IR、XRD、SEM对其基本结构进行了研究.     

纳米碳管结构差异对树脂炭包覆硅/纳米碳管复合材料电化学性能的影响

采用聚乙烯醇（PVA）树脂炭化的方法，制备了PVA树脂炭包覆硅／不同纳米碳管复合材料，通过X-射线、高分辩电镜观察和电化学性能测试等手段比较研究了单壁、双壁和多壁纳米碳管作为弹性导电网络缓解硅在充放电过程中体积变化方面的效果。结果表明，单壁纳米碳管和双壁纳米碳管比多壁纳米碳管能够更好地缓解硅在循环过程中产生的结构和体积变化，这主要是因为其长径比大，缠裹效果更好。单壁纳米碳管和双壁纳米碳管具有相近的直径、长径比及宏观分布形式，但在循环过程中，双壁纳米碳管的结构稳定性好于单壁纳米碳管，进而其缓解硅结构变化的效果更好。     

一种新颖的硅量子点-金复合纳米粒子的制备和表征

利用电化学刻蚀法制备的硅量子点的还原特性,通过调整硅量子点与氯金酸的量的比例,可控合成了包含有不同尺寸金纳米颗粒的复合纳米粒子,并通过实验证明了硅量子点与金纳米颗粒的结合。在电化学刻蚀制备硅量子点的同时,通过微波辅助法可以迅速地在硅量子点表面有效地修饰上一部分羧基、羟基或者烷基链,从而间接预先对这种复合纳米粒子进行修饰。这种新型的纳米复合材料具有硅量子点的荧光性质的同时,还具有各种尺寸纳米金的光学性质,具有广阔的应用前景和研究价值。     

纳米电子器件呼唤真空化学研究

纳米电子器件是微电子器件发展的下一代，现有微电子器件的主要材料是极纯的硅、锗和镓砷等晶体地体。纳米电子器件有可能是以有机或有机／无机复合本薄膜为主材料，要求纯度更高，结构更完善。真空制备的清洁环境，有希望加工组装出纳米电子器件所要求的结构。故本建议开展真空化学研究。     

纳米材料在包装机械上的应用研究

近年来,功能性包装材料的研究开发受到了广泛的重视,而纳米科技的出现,为人们提供了全新的思路和技术支持.高分子纳米复合材料是由各种纳米单元与高分子材料以各种方式复合成型的一种新型复合材料,所采用的纳米单元按成分分可以是金属,也可以是陶瓷、高分子等,由零维、一维、二维或三维及中间维数相构成.由于高分子纳米复合材料既有纳米粒子自身的特性,又兼有高分子材料本身的优点,因此它在催化、力学、物理性能等方面应用前景十分广阔.如今,纳米陶瓷、纳米塑料、纳米抗菌材料以及纳米橡胶等已逐渐在包装领域得到应用.     

Strain engineering of nanoscale Si P-type metal-oxide-semiconductor field-effect transistor devices with SiGe alloy integrated with contact-etch-stop layer stressors

Strained-silicon (Si) has been incorporated into a leading nanoscale logic technology. By means of silicon-germanium (SiGe) alloy stressor embedded in source and drain (S/D) region, the performance of P-type metal-oxide-semiconductor field-effect transistors (PMOSFETs) is effectively enhanced. However, when a compressive contact-etch-stop layer (CESL) is combined, the stress interaction and relative impacts of SiGe stressor integrated with CESL on mobility enhancement has been little reported. Therefore, the research performs a three dimensional (3D) stress simulation evaluation based on finite element method (FEM) for PMOSFETs with S/D SiGe stressor and compressive CESL. The proposed simulation methodology is validated as compared with other technological literatures. In additions, the gate width dependency is systematically discussed to explore the stress effects on devices. The analysis results indicate that a -2.6 GPa CESL would continue boosting the stress magnitude on Si channel region except for a gate width smaller than 50 nm. The results are useful for nanoscale transistor while selecting a proper CESL in the manufacturing processes of advanced logic technologies.     

氧化铝一维纳米材料制备方法的研究进展

氧化铝一维纳米材料由于其独特的结构成为材料研究的热点之一,近年来国内外有关其制备方法的报道也相对较多.较全面地介绍了氧化铝一维纳米材料的制备方法,包括VLS法、VS法、水热法、溶胶-凝胶法和模板法等.分析了各类方法的特点,指出了制备氧化铝一维纳米材料存在的问题,并展望了其未来的发展.     

Interfacial energy between carbon nanotubes and polymers measured from nanoscale peel tests in the atomic force microscope

The future development of polymer composite materials with nanotubes or nanoscale fibers requires the ability to understand and improve the interfacial bonding at the nanotube–polymer matrix interface. In recent work [Strus MC, Zalamea L, Raman A, Pipes RB, Nguyen CV, Stach EA. Peeling force spectroscopy: exposing the adhesive nanomechanics of one-dimensional nanostructures. Nano Lett 2008;8(2):544–50], it has been shown that a new mode in the Atomic Force Microscope (AFM), peeling force spectroscopy, can be used to understand the adhesive mechanics of carbon nanotubes peeled from a surface. In the present work, we demonstrate how AFM peeling force spectroscopy can be used to distinguish between elastic and interfacial components during a nanoscale peel test, thus enabling the direct measurement of interfacial energy between an individual nanotube or nanofiber and a given material surface. The proposed method provides a convenient experimental framework to quickly screen different combinations of polymers and functionalized nanotubes for optimal interfacial strength.     

Molding and replication of ceramic surfaces with nanoscale resolution

The design of reproducible and more efficient nanofabrication routes has become a very active research field in recent years. In particular, the development of new methods for micro- and nanopatterning materials surfaces has attracted the attention of many researchers in industry and academia as a consequence of the growing relevance of patterned surfaces in many technological fields, ranging from optoelectronics to biotechnology. In this work we explore, discuss, and demonstrate the possibility of extending the well-known molding and replication strategy for patterning ceramic materials with nanoscale resolution. To achieve this goal we have combined physical deposition methods, molecule-thick anti-sticking coatings, and nanostructured substrates as master surfaces. This new perspective on an "old technology", as molding is, provides an interesting alternative for high-resolution, direct surface-relief patterning of materials that currently requires expensive and time-consuming lithographic approaches.     

热喷涂纳米粉体材料及其涂层制备

介绍了国外喷涂用纳米结构喂料的制备方法，以及采用几种先进的热喷涂技术制备的纳米结构涂层，并指出非晶/纳米晶涂层是该领域研究的重中之重。与传统喷涂层相比，纳米结构涂层在耐磨、防腐性能方面呈现出优异性能和良好的发展前景。     

一维ZnO纳米结构的场发射研究进展

一维纳米结构材料因其优异的电、光及场发射特性，在光电器件、场发射器件等方面具有重要的应用价值而备受关注。ZnO因具有优异的化学及热稳定性，并且其一维纳米结构具有极大的场增强因子，因而在场发射器件阴极中有良好的应用前景。首先简要介绍了ZnO的结构与性质，并重点介绍了ZnO一维纳米材料的常用制备技术及其在场发射领域的研究进展。     

Light scattering from self-affine fractal silver surfaces with nanoscale cutoff: far-field and near-field calculations

We study the light scattered from randomly rough, one-dimensional, self-affine fractal silver surfaces with nanoscale lower cutoff illuminated by s- or p-polarized Gaussian beams a few micrometers wide. By means of rigorous numerical calculations based on the Green's theorem integral equation formulation (GTIEF), we obtain both the far- and near-field scattered intensities. The influence of diminishing the size of the fractal lower-scale irregularities (from approximately 50 nm to a few nanometers) is analyzed in the case of both single realization and ensemble-average magnitudes. For s polarization, variations are small in the far field, being significant only in the higher-spatial-frequency components of evanescent character in the near field. In the case of p polarization, however, the nanoscale cutoff has remarkable effects stemming from the roughness-induced excitation of surface-plasmon polaritons. In the far field, the effect is noticed both in the speckle pattern variation and in the decrease of the total reflected energy upon ensemble averaging, as a result of increased absorption. In the near field, more efficient excitation of localized optical modes is achieved with smaller cutoff, which in turn leads to huge surface electric field enhancements.     

The synthesis and fabrication of one-dimensional nanoscale heterojunctions

There are a variety of methods for synthesizing or fabricating one-dimensional (1D) nanostructures containing heterojunctions between different materials. Here we review recent developments in the synthesis and fabrication of heterojunctions formed between different materials within the same 1D nanostructure or between different 1D nanostructures composed of different materials. Structures containing 1D nanoscale heterojunctions exhibit interesting chemistry as well as size, shape, and material-dependent properties that are unique when compared to single-component materials. This leads to new or enhanced properties or multifunctionality useful for a variety of applications in electronics, photonics, catalysis, and sensing, for example. This review separates the methods into vapor-phase synthesis, solution-phase synthesis, template-based synthesis, and other approaches, such as lithography, electrospinning, and assembly. These methods are used to form a variety of heterojunctions, including segmented, core/shell, branched, or crossed, from different combinations of semiconductor, metal, carbon, and polymeric materials.     

A hybrid mask-mould lithography scheme and its application in nanoscale organic thin film transistors

Nanoimprint lithography (NIL) has stimulated great interest in both academic research and industrial development due to its high resolution, high throughput and low cost advantages. Though NIL has been demonstrated to be very successful in replicating nanoscale features, it also has its limitations as a general lithography technique. Its fundamental moulding characteristics (i.e.?physically displacing polymer materials) frequently lead to pattern defects when replicating arbitrary patterns, especially patterns with broad size distribution. To solve this problem, we have developed a combined nanoimprint and photolithography technique that uses a hybrid mould to achieve good pattern definitions. In this work, we applied this technique to fabricate finger-shaped nanoelectrodes, and demonstrated nanoscale pentacene organic thin film transistors (OTFTs). Methods of the hybrid mask-mould (HMM) fabrication and results on the device electrical characteristics are provided. With combined advantages of both photolithography and NIL, and the applicability to general nanoscale device and system fabrication, this method can become a valuable choice for low cost mass production of micro-?and nanoscale structures, devices and systems.