低能Kr+离子束诱导蓝宝石晶体实验研究

使用微波回旋共振离子源制备蓝宝石(A向)自组织纳米结构,研究不同入射角度下Kr+离子束刻蚀蓝宝石表面形成的自组织纳米结构及其形成过程.采用等离子体与离子束刻蚀设备在不同入射角度下对蓝宝石样品表面进行刻蚀并通过Taylor Surf CCI2000非接触式表面测量仪和原子力显微镜分别对刻蚀后的蓝宝石样品的刻蚀速率及表面形貌进行分析.研究表明:当离子束能量为400eV,加速电压为200V,离子束流密度为310μA/cm2时,小角度入射下,蓝宝石样品表面出现纵向尺度较小的有序点状纳米结构;随着入射角度的增加,样品表面形成条纹状纳米结构,30°时形成短程有序且纵横比为0.87的条纹状结构;入射角度继续增加,纵向高度减小直至纳米结构消失;当角度达到60°附近,蓝宝石表面又出现条纹状结构,70°时形成了短程有序且纵横比为1.07的条纹状结构.自组织纳米结构的形成先以"岛状"形式出现,随后岛上生长出条纹状纳米结构,随着刻蚀时间的增加,岛状条纹结构纵向尺度增大且有序性增强,纳米结构的横向周期不变.     

Si纳米量子点的LPCVD自组织化形成及其生长机理研究

采用低压化学汽相沉积(LPCVD)方法，依靠纯SiH₄气体分子的表面热分解反应， 在由Si—O—Si键和由Si—OH键终端的两种SiO₂表面上，自组织生长了Si纳米量子点. 实 验研究了所形成的Si纳米量子点密度随SiO₂表面的反应活性位置数、沉积温度以及反应气 压的变化关系. 依据LPCVD的表面热力学过程，定性地分析了Si纳米量子点的形成机理.研究结果对具有密度分布均匀和晶粒尺寸可控的Si纳米量子点的自组织生长，以及Si基新型量子电子器 关键词： Si纳米量子点 LPCVD 自组织化形成 生长机理     

基于DNA自组装的金属纳米结构制备及相关纳米光子学研究

纳米光子学是研究光在纳米尺度下的行为以及光和纳米材料相互作用的一门科学.金属纳米材料凭借其独特的表面等离子体效应,可以在衍射极限以下对光进行传递和聚焦,因而是纳米光子学研究的重点.大量研究表明,通过调控金属纳米材料的形貌和成分可以控制表面等离子体的性质,从而对光进行可控调节.近年来,随着DNA纳米技术的发展,又为纳米光子学的发展带来了新的机遇.首先,人们发现不同的DNA序列可以调控金属纳米颗粒的成长,从而影响金属纳米颗粒的形貌和成分.此外,利用DNA自组装技术,可以将金属纳米颗粒组装成为有序可控的纳米结构.因此,基于DNA的纳米光子学研究近年来发展十分迅速.在此背景下,本文对相关研究进行归纳与总结,以期吸引更多研究人员的关注,推动该领域的进一步发展.本文首先介绍了金属纳米结构基于表面等离体实现突破光学衍射极限的原理,然后按照DNA对金属纳米结构的形貌或成分影响方式的不同分成若干部分,对基于DNA的纳米光子学做了系统的综述,最后展望了未来可能的发展方向.     

应变异质外延生长中的自组织纳米结构

具有纳米尺度的三维岛的阵列能在有应变的外延生长薄膜上自组织生长，包括反量子点和量子分子在内的其他结构在合适的生长或退火条件下也被观测到。讨论了有关这些纳米结构自组织生长的动力学蒙特卡罗模拟计算中的最新进展。     

基于表面等离激元光镊的新型纳米热源研究

针对纳米尺度热现象研究的需求,基于表面等离激元光镊对金纳米颗粒的动态操控能力,设计了一种实时、动态、可控的纳米热源。利用有限元法对光镊系统中金纳米颗粒的光热效应与表面等离激元电磁场强度的关系进行了模拟,阐明了由于表面等离激元和局域表面等离激元的耦合作用导致的电磁场能量聚集和增强,以及同时实现的金属纳米颗粒的光热效应;分析了在该光镊系统捕获金属颗粒过程中颗粒所产生的热效应,并由此得到了实时控制纳米热源热功率的方法。在理论研究的基础上设计实验并证实了该光镊系统中金纳米颗粒基于光热效应的加热能力。结合表面等离激元光镊系统对纳米热源的精确定位操控能力,该系统为纳米尺度热现象的研究提供了灵活而可靠的手段。     

PED沉积La-Sr-Cu-O薄膜表面的有序纳米结构

采用脉冲电子束沉积(PED)技术在Si(100)衬底上生长La_Sr_Cu_O薄膜，在750℃生长温度下获得具有有序纳米结构的表面形貌.采用聚集离子束(FIB)技术对获得的纳米结构进行表征，结果表明，这种有序的纳米结构是由于Si衬底和La_Sr_Cu_O薄膜之间的热膨胀系数和晶格的 失配引起的纳米裂纹.在这些纳米裂纹处，La_Sr_Cu_O成核生长获得独立的纳米线.通过控制 这种有序的纳米结构的生长，这种有序的纳米结构可以用来构造弱连接形成的器件. 关键词： 脉冲电子束沉积 La_Sr_Cu_O薄膜 纳米结构     

未来十年纳米光子学若干重点发展领域

纳米光子学已经对人们的日常生活产生了重要影响,并且纳米光子学器件产品有强大的市场需求,因此其研究结果可以很快转化为商品。文章介绍了在未来5到10年内对光子工业有重大影响并且有望进入商品市场的11个纳米光子学领域,其中包括:纳米尺度量子光子学、全光路由、用于增强磁存储的表面等离子体光子学、用于诊断治疗和药物输送纳米光子学、纳米成像、分子尺度上的化学与生物传感器、纳米标签、纳米尺度上操控光场的分布(光伏器件和LED/OLED)、原型试制的新技术、量身定制光学特性的纳米光子材料以及太赫兹技术等,希望文章能对中国的纳米光子学研究及其工业化应用有一定帮助。     

金属纳米椭球结构表面的局域电场和吸附分子分布

过渡金属纳米结构表面吸附CO分子时会出现异常红外效应,这一现象可以用纳米结构表面吸附分子在外电场作用下产生局部凝聚从而相互作用能增加来解释.在前期研究的基础上,给出金属基底表面生长出的纳米颗粒为椭球状颗粒的理论计算结果.基于均匀外电场中金属纳米椭球颗粒按一定对称性排列的表面结构模型,用经典电磁学理论计算了纳米椭球颗粒表面附近的局域电场.在此基础上,将吸附的CO分子等效为偶极子,在考虑了偶极子与局域电场、偶极子之间以及偶极子与金属基底三种相互作用的情况下,用Monte-Carlo方法进行数值模拟,最后给出纳 关键词： 金属纳米结构表面 纳米椭球 吸附分子 局域电场     

在Si衬底上自组装生长Ge量子点研究进展

在Si衬底上自组装生长纳米尺度的Ge量子点，由于三维量子限制效应的贡献，能够在能带结构上对Si、Ge天然材料的间接带特性实施准直接带结构的改性，使激子行为和带间复合跃迁得到大幅度增强，同时Ge量子点的可控有序相关排列还有助于发展新一代的Si基电子波量子器件．文章回顾了自20世纪80年代末至今Ge／Si量子点生长研究的重要进展，对其潜在的重要应用作出了评述．结合作者自己的研究结果，着重介绍了Ge量子点的生长动力学及其形态的演变过程，指出自组装生长的Ge／Si量子点属Ⅱ型能带结构，其发光效率比一维量子阱有很大增强．探讨了用模板衬底实现对Ge量子点尺寸和分布的有序可控生长方法与途径．     

一维光传输介质中折射率波动的统计表征

介绍了一种基于介观反射光谱分析的纳米尺度折射率波动表征的方法,揭示了介观反射光谱用于纳米尺度折射率波动表征的机理.采用时域有限差分方法,分析了光在一维折射率分布介质中的传播情况和光谱特征,并通过精确控制一维通道内部折射率波动的标准差和空间相关长度,定量分析了混乱度的仿真计算值及其与理论设置值的关系.结果表明,反射光谱对...     

Si(001)表面稀土金属硅化物纳米结构

稀土金属元素的硅化物在n型硅衬底上具有高电导率和低肖特基势垒的特点，在大规模集成的微电子器件领域具有很好的应用价值．文章系统介绍了在Si（001）表面自组装生长的稀土金属硅化物纳米结构的研究进展，较全面地讨论了退火温度、退火时间以及稀土金属表面覆盖度等生长条件对纳米结构生长的影响作用，并在此基础上分析了纳米线、纳米岛的晶化结构，衬底对纳米结构生长的影响，以及纳米结构的演化过程．搞清楚这些内在的生长机理，有助于人们今后实现可严格控制稀土金属硅化物纳米结构的形貌尺寸和分布的自组装生长．此外，文章还介绍了目前人们对稀土金属硅化物纳米线电学性质的研究进展．     

Plasmas meet plasmonics

The term ‘plasmon’ was first coined in 1956 to describe collective electronic oscillations in solids which were very similar to electronic oscillations/surface waves in a plasma discharge (effectively the same formulae can be used to describe the frequencies of these physical phenomena). Surface waves originating in a plasma were initially considered to be just a tool for basic research, until they were successfully used for the generation of large-area plasmas for nanoscale materials synthesis and processing. To demonstrate the synergies between ‘plasmons’ and ‘plasmas’, these large-area plasmas can be used to make plasmonic nanostructures which functionally enhance a range of emerging devices. The incorporation of plasma-fabricated metal-based nanostructures into plasmonic devices is the missing link needed to bridge not only surface waves from traditional plasma physics and surface plasmons from optics, but also, more topically, macroscopic gaseous and nanoscale metal plasmas. This article first presents a brief review of surface waves and surface plasmons, then describe how these areas of research may be linked through Plasma Nanoscience showing, by closely looking at the essential physics as well as current and future applications, how everything old, is new, once again.     

Ultra‐fast nano‐optics

Ultra‐fast nano‐optics is a comparatively young and rapidly growing field of research aiming at probing, manipulating and controlling ultrafast optical excitations on nanometer length scales. This ability to control light on nanometric length and femtosecond time scales opens up exciting possibilities for probing dynamic processes in nanostructures in real time and space. This article gives a brief introduction into the emerging research field of ultrafast nano‐optics and discusses recent progress made in it. A particular emphasis is laid on the recent experimental work performed in the authors' laboratories. We specifically discuss how ultrafast nano‐optical techniques can be used to probe and manipulate coherent optical excitations in individual and dipole‐coupled pairs of quantum dots, probe the dynamics of surface plasmon polariton excitations in metallic nanostructures, generate novel nanometer‐sized ultrafast light and electron sources and reveal the dipole interaction between excitons and surface plasmon polaritons in hybrid metal‐semiconductor nanostructures. Our results indicate that such hybrid nanostructures carry significant potential for realizing novel nano‐optical devices such as ultrafast nano‐optical switches as well as surface plasmon polariton amplifiers and lasers.     

基于含时密度泛函理论的表面等离激元研究进展

纳米粒子的局域表面等离激元(LSP)由于其新颖的光学特性成为目前国内外研究的热点之一. 本文利用含时密度泛函理论(TDDFT)对金属团簇及石墨烯纳米结构中的等离激元激发及调制的物理本质进行了研究. 和宏观大小的材料相比, 由于纳米结构的尺寸和量子受限效应, 纳米结构的等离激元具有一些不同的特征. 在低能共振区, 光谱线发生展宽, 并且发生劈裂. 由于纳米单体间的电磁耦合作用, 使聚合的纳米结构表现出了与单体不同的光学性质. 这些结果为等离激元的调控提供了坚实的理论指导.     

金纳米棒核/贵金属壳杂化纳米结构的可控制备和性质调控

贵金属纳米颗粒由于其独特的光学及催化性能引起了人们的广泛关注,而这些性能与纳米颗粒的尺寸、形貌、结构组成等密切相关.目前如何有意识地控制晶体生长过程,以得到人们需要的纳米结构和组成,仍具有相当大的挑战性.文章重点介绍了利用具有特定形貌和晶面组成的金纳米棒（Au nanorods）作为种子,借助形成核/壳结构,诱导了Ag...     

A novel way of modifying nano grain size by solution concentration in the growth of ZnAl<Subscript>2</Subscript>O<Subscript>4</Subscript> thin films

A novel route to the growth of thin films of ZnAl₂O₄ in nano-scale order was developed and nano-thin films of ZnAl₂O₄ are grown. The variation of grain size with solution concentration is reported. The thin film was deposited by modified liquid-phase deposition (LPD) technique using a novel acid based chemical reaction for the first time to ternary system. This modified LPD is based on a novel reaction that favours the formation of nanostructures during the treatment of a precursor (here ZnO) and a metal foil (Al) in diluted HF acid. The acid serves both as a solvent and catalyst. Usually, in wet process synthesis of binary systems, the metal foil will act as F⁻ ion scavenger. In this method, formation of a ternary compound as well as growth of thin film nanostructures of that compound was achieved by the same chemical reaction at room temperature. The role of acid concentration in the nanostructure formation is discussed. The relationship between HF concentration and grain size were also graphically enumerated. Structural, compositional and surface morphological properties of thin films were studied using Philips, Xpert-MPD: X-ray diffractometer and Philips, ESEM-TMP + EDAX, Nanoscope-III: AFM. The technique is a novel, simple and low cost route for the growth of nano-thin films of ternary oxide material.     

Semiconductor nanostructures enabled by aerosol technology

Aerosol technology provides efficient methods for producing nanoparticles with well-controlled composition and size distribution. This review provides an overview of methods and results obtained by using aerosol technology for producing nanostruetures for a variety of applications in semiconductor physics and device technology. Examples are given from： production of metal and metal alloy particles： semiconductor nanoparticles; semiconductor nanowires, grown both in the aerosol phase and on substrates; physics studies based on individual aerosol-generated devices; and large area deviees based on aerosol particles.     

New progress of plasmonics in complex metal nanostructures

Noble metal nanostructures possess novel optical properties because of their collective electronic oscillations,known as surface plasmons(SPs).The resonance of SPs strongly depends on the material,surrounding environment,as well as the geometry of the nanostructures.Complex metal nanostructures have attracted research interest because of the degree of freedom in tailoring the plasmonic properties for more advanced applications that are unattainable by simple ones.In this review,we discuss the plasmonic properties of several typical types of complex metal nanostructures,that is,electromagnetically coupled nanoparticles(NPs),NPs/metal films,NPs/nanowires(NWs),NWs/NWs,and metal nanostructures supported or coated by dielectrics.The electromagnetic field enhancement and surface-enhanced Raman scattering applications are mainly discussed in the NPs systems where localized SPs have a key role.Propagating surface plasmon polaritons and relevant applications in plasmonic routers and logic gates using NWs network are also reviewed.The effect of dielectric substrates and surroundings of metal nanostructures to the plasmonic properties is also discussed.     

Self-organized epitaxial growth on spontaneously nano-patterned templates

Self-ordering at crystal surfaces has been the subject of intense efforts during the last ten years, since it has been recognized as a promising way for growing uniform nanostructures with regular sizes and spacings in the 1–100 nm range. In this article we give an overview of the self-organized nanostructures growth on spontaneously nano-patterned templates. A great variety of surfaces exhibits a nano-scale order at thermal equilibrium, including adsorbate-induced reconstruction, surface dislocations networks, vicinal surfaces or more complex systems. Continuum models have been proposed where long-range elastic interactions are responsible for spontaneous periodic domain formation. Today the comparison between experiments such as Grazing Incidence X-Ray Diffraction experiments and calculations has lead to a great improvement of our fundamental understanding of the physics of self-ordering at crystal surfaces. Then, epitaxial growth on self-ordered surfaces leads to nanostructures organized growth. The present knowledge of modelization of such an heterogeneous growth using multi-scaled calculations is discussed. Such a high quality of both long-range and local ordered growth opens up the possibility of making measurements of physical properties of such nanostructures by macroscopic integration techniques. To cite this article: S. Rousset et al., C. R. Physique 6 (2005).