基于直接胶体晶体刻蚀技术的高度有序纳米硅阵列的尺寸及形貌控制

以自组装单层胶体小球阵列为掩模，采用直接胶体晶体刻蚀技术在硅表面制备二维有序尺寸可控的纳米结构.在样品制备过程中，首先通过自组装法在硅表面制备了直径200nm的单层聚苯乙烯(PS)胶体小球的二维有序阵列；然后对样品直接进行反应离子刻蚀(RIE)，以氧气为气源，利用氧等离子体对聚苯乙烯小球和对硅的选择性刻蚀作用，通过改变刻蚀时间，制备出不同尺寸的PS胶体小球的有序单层阵列；接着以此二维PS胶体单层膜为掩模，以四氟化碳为气源对样品进行刻蚀；最后去除胶体球后得到二维有序的硅柱阵列.SEM和AFM的测量结果表明：改变氧等离子体对胶体球的刻蚀时间和四氟化碳对硅的刻蚀时间，可以控制硅柱的尺寸以及形貌，而硅柱阵列的周期取决于原始胶体球的直径. 关键词： 胶体晶体刻蚀 纳米硅柱阵列     

基于二维胶体晶体刻蚀法的纳米颗粒阵列

悬浮液中的胶体球在一定条件下能够自组装成二维胶体晶体，以此为掩膜可合成纳米颗粒阵列体系，其颗粒形状、尺寸以及间距等参数易于控制。调整这些参数和相应的介质环境可以实现对颗粒阵列体系性质的有效控制，这也为研究尺寸效应提供了便利，且在一些具有特殊功能的纳米器件方面具有潜在的应用价值。文章重点介绍了这种阵列体系的合成过程、结构形态和性质，并展望了其应用前景。     

胶体晶体和基于胶体晶体的纳米结构

胶体晶体及基于胶体晶体的各种纳米结构的制备和物理性质是近来物理学和材料科学共同关注的一个热点，文章简要阐述了胶体颗粒间的基本相互作用，着重介绍了各种胶体晶体的制备方法；结合我们近期的工作，综合评述了胶体晶体在二维纳米颗粒阵列、二维有序孔单层膜及三维光子晶体等纳米结构材料研究中的应用，并对未来的发展进行了展望。     

铬过渡层对纳米球刻蚀法制备二维银纳米结构的影响

研究了铬过渡层对纳米球刻蚀法制备二维银纳米点阵结构的影响。首先利用自组装的方法在玻璃基底上制备出单层排列的聚苯乙烯纳米球阵列,然后使用物理气相沉积的方法在二维聚苯乙烯纳米球阵列上沉积一层铬层作过渡层和银层,最后将玻璃基底在乙醇溶液中超声移除聚苯乙烯纳米球,得到二维的银纳米点阵。实验发现,随着铬过渡层厚度的增加,制得的二维银纳米点阵阵列趋于完整,单个的银纳米颗粒由椭圆状转变为三角形形状。实验中测量了所得到的二维银纳米结构的吸收光谱。     

二维有序磁性Co纳米球阵列膜构筑及其光学性能研究

周期性纳米结构阵列因其独特的光学效应在新型传感技术领域具有巨大的应用潜力,引起人们极大的兴趣。其光学特性依赖于形貌和结构参数,一般可通过调整这些参数来调控其光学性能,而通过外加磁场调节其光学性能鲜有报道。通过气液自组装法制备胶体晶体模板,采用等离子体刻蚀技术实现了对胶体晶体模板结构尺寸的调控。在此基础上,结合磁控溅射技术合成了具有六角周期性排列的亚波长尺寸磁性Co纳米球阵列膜,并研究了其在结构参数和外磁场作用下的光学性质。通过紫外-可见-近红外光反射谱发现,随着刻蚀时间从0 min增加到4.5 min,在可见光波段,光反射峰波长从512 nm蓝移到430 nm,蓝移了82 nm,峰强从10.69%降低到7.96%,减弱了2.73%;在近红外光波段,光反射峰波长从1 929 nm蓝移到1 692 nm,蓝移了237 nm,峰强从10.92%降低到7.91%,减弱了3.01%。通过控制刻蚀的时间,可实现对Co纳米球阵列膜光反射峰峰位和峰强的有效调控。对未刻蚀和刻蚀的Co纳米球阵列膜施加一个垂直的外加磁场,在外磁场作用下,二者的光反射峰峰强均表现出不同程度的增强。随着外加磁场的逐增,未经刻蚀...     

纳米球刻蚀法制备的二维有序的CdS纳米阵列及其光学性质的研究

采用纳米球刻蚀(nanosphere lithography)技术,以自组装的聚苯乙烯纳米小球(polystyrene,PS小球)的单层膜为掩模,制备出二维有序的CdS纳米阵列.利用扫描电子显微镜(SEM)对样品结构进行了表征,用紫外—可见分光光度计对样品光学性质进行了分析.结果表明：制备的二维CdS纳米阵列是高度有序的,且与作为掩模的纳米小球的原始尺寸及排布结构一致;禁带宽度为2.60eV,相对于体材料的2.42eV,向短波长蓝移了0.18eV,表现出CdS材料在纳米结构点阵中的量子尺寸效应;CdS纳米 关键词： 纳米球刻蚀 二维CdS纳米有序阵列     

多层金属纳米点阵的制备及其光学性质的研究

采用纳米球刻蚀法结合热蒸发技术制备了银和氧化硅交替层叠的纳米颗粒阵列. 扫描隧道显微镜测量结果表明, 该纳米阵列呈锥形多层结构. 分光光度计测量样品表明, 该纳米阵列在近红外波段存在明显的透射谷, 该透射谷来源于金属纳米颗粒局域等离激元的激发, 随着金属/介质层数的增多, 透射谷的位置向短波方向移动. 利用HFSS软件对该纳米阵列进行了仿真, 并分析了透射谷蓝移的原因. 关键词： 纳米球刻蚀技术 金属/介质纳米颗粒 表面等离子激元     

电阻热蒸发镀膜与电子束蒸发镀膜对纳米球刻蚀方法制备二维银纳米阵列结构的影响

在使用纳米球刻蚀法制备二维银纳米点阵的过程中,使用不同的镀膜方法在同样的模板上得到了不同形貌的银纳米阵列结构.使用电阻热蒸发镀膜方法获得了六角排列的银纳米三角形阵列结构,使用电子束蒸发镀膜方法则获得了六角排列的银纳米环阵列结构.研究表明,沉积纳米粒子的粒径、表面纳米曲率效应和热能是形成不同结构形貌的纳米阵列结构的关键因素. 关键词： 银纳米阵列 电阻热蒸发 电子束蒸发 纳米球刻蚀     

基于PS球刻蚀技术制备纳米孔滤波器结构的优化分析

金属纳米孔阵列作为彩色滤波器件在OLED中有很好的应用前景。本文提出利用胶体晶体刻蚀与真空沉积技术制作大面积金属纳米孔阵列滤波器,并用FDTD模拟优化所需要加工的金属孔阵列的结构参数,分析了其滤波效果及其物理规律和机制。研究表明:在选择粒径为720 nm的PS球、刻蚀剩余粒径为240nm、金属膜厚度为120 nm的条件下,满足CIE红光显示标准的共振波长为704.06 nm,强度透射率为52%,透射谱带宽为24.8 nm。模拟结果为用PS球刻蚀技术制备金属纳米孔阵列的实验提供了理论支持。     

有序金纳米颗粒阵列的制备及光吸收特性研究

采用纳米球刻蚀技术中漂移法在玻璃基片上制备较大 面积不同直径的聚苯乙烯小球掩模板, 采用磁控溅射技术在掩模板上沉积不同厚度的金薄膜, 去除聚苯乙烯小球后, 通过扫描电子显微镜观察到周期排列的三角状金纳米颗粒点阵. 通过紫外-可见分光光度计测试所制备样品的光吸收特性, 发现表面等离子体共振峰随粒径增大发生红移, 随金纳米颗粒高度增加发生蓝移. 基于Mie理论, 利用Matlab软件编程对不同粒径的金阵列光吸收特性进行理论模拟, 并与实验结果进行对比. 关键词： 纳米球刻蚀 金纳米颗粒阵列 表面等离子体共振     

Top-gathering pillar array of hybrid organic–inorganic material by means of self-organization

Two-dimensional (2D) pillar arrays with submicrometer to micrometer repetitions have been fabricated from hybrid organic–inorganic material by mask lithography or multi-beam interference lithography. The type of array structure depends on structural parameters such as the pillar height, diameter and distance between neighboring pillars. Two kinds of periodic arrays, 2D arrays and ‘top-gathering’ arrays, can be obtained by controlling the structural parameters. In the top-gathering arrays, the pillars are gathered at the top by means of self-organization, and ‘top-gathering’ units composed of four pillars can be formed. PACS 68.35.Gy; 81.20.Fw; 82.50.-m     

1D to 2D transitional structure of plasmonic crystals: fabrication and characterization

A very interesting structure that has not been explored previously is an array of “corrugated/wavy” lines; an intermediate structure between 1D grating and 2D arrays of plasmonic crystal. This novel structure is studied to fully understand the transitional effect from 1D line to 2D arrays. The changes in geometry will subsequently change the effective refractive index of the crystal hence alters the plasmonic coupling conditions. The azimuthal effect of this structure is also explored to control the SPP magnitude and propagation direction. Interference lithography (IL) technique is used to fabricate this structure. Some geometrical parameters can be controlled in order to optimize the coupling condition for SPP propagation. This will lead us to understand the fundamental geometrical contributions to the field enhancement. Comprehensive mathematical simulations that model these effects to the SPP coupling condition has been undertaken to understand the plasmonic coupling efficiency and the azimuthal angle dependence.     

Fabrication of large-scale periodic silicon nanopillar arrays for 2D nanomold using modified nanosphere lithography

We present a fabrication procedure that can form large-scale periodic silicon nanopillar arrays for 2D nanomold which determines the feature size of nanoimprint lithography, using modified nanosphere lithography. The size of silicon nanopillars can be easily controlled by an etching and oxidation process. The period and density of nanopillar arrays are determined by the initial diameter of polystyrene (PS) spheres. In our experiment, the smallest nanopillar has a full width half maximum (FWHM) of approximately 50 nm, and the density of silicon pillar is ∼10⁹/cm². Using this approach, it is possible to fabricate 2D nanoimprint lithography mask with 50 nm resolution.     

Solution Lithography for Colloidal Crystal Patterning: Revisiting Flory–Huggins Interaction Parameters and Co-Nonsolvent Systems

For fundamental studies and practical applications, colloidal crystal patterns on substrates are typically fabricated through etching and conventional lithography. However, a wet-chemical based method is necessary for simplifying the procedure, preserving the substrate structure, and reproducibly fabricating the colloidal crystal patterns. The present study demonstrates that colloidal crystal patterns can be conveniently generated using thermodynamic relationships between a polymer colloid and surrounding solvents. Close-packed colloidal monolayers in good solvents that cause colloidal swelling spontaneously transform into non–close-packed crystal patterns when non-solvents that cause their shrinkage replace the good solvents. The colloid diameter in the close-packed monolayer decreases significantly when the polymer in the colloid is passing thermodynamic theta conditions (when Flory–Huggins interaction parameters increase to higher than ≈0.5). The close-packed monolayers also transform into the patterns in co-nonsolvent conditions. The “solution lithography” might be particularly useful for patterning colloids on curved microstructures and plastic/flexible films. The colloidal shapes in the patterns vary with the solvent pairs and substrates. The method does not require special facilities to reproducibly fabricate the patterns. The study further suggests methods simultaneously fixing the patterns. The patterns exhibit anti-reflection properties. Therefore, the solution lithography is applicable to optics, electronics, analytical science, and energy systems.     

Fabrication of two-dimensional colloidal arrays

We report the effective fabrication of two-dimensional (2D) arrays of submicron colloidal particles. These colloidal arrays are produced in thin layers of monodisperse colloid suspensions on flat surfaces of solids such as clean glass or cleaved mica. The process of colloid assembling includes two steps, nucleation and growth, similar to those found in crystallization in solution but each of the steps in detail progresses with different mechanisms. The nucleation process is initiated by a special kind of capillary force acting parallel to the surface. The growth is guided by a laminar flow of water to the crystals, which is driven by water evaporation from 2D arrays. What is distinguishable in the 2D assembling is its active nature governed by the forces and flows, making a contrast to the diffusive mechanism in ordinary crystallization. With this two-step mechanism, a domain of hexagonally packed colloidal array can grow with time. A large and uniform film of particle monolayer is, thus, formed in a short period, from several seconds up to several minutes depending on the conditions controlled.     

一种简单高效的制备硅纳米孔阵结构的方法

本文介绍了一种简单高效的制备硅纳米孔阵结构的方法. 利用激光干涉光刻技术, 结合干法和湿法刻蚀工艺, 直接将光刻胶点阵刻蚀为硅纳米孔阵结构, 省去了图形反转工艺中的金属蒸镀和光刻胶剥离等必要步骤, 在2英寸的硅 (001) 衬底上制备了高度有序的二维纳米孔阵结构. 利用干法刻蚀产生的氟碳有机聚合物作为湿法刻蚀的掩膜, 以及在干法刻蚀时对样品进行轻微的过刻蚀, 使SiO₂点阵图形下形成一层很薄的硅台面, 是本方法的两个关键工艺步骤. 扫描电子显微镜图片结果表明制备的孔阵图形大小均匀, 尺寸可控, 孔阵周期为450 nm, 方孔大小为200–280 nm. 关键词： 激光干涉光刻 纳米阵列 刻蚀 氟碳有机聚合物     

Al纳米颗粒表面等离激元对ZnO光致发光增强的研究

基于聚苯乙烯球自组装法,在P型氮化镓(P-GaN)衬底上制备了有序致密的掩模板;采用热蒸发法在该模板上沉积金属Al薄膜,通过甲苯溶液去除聚苯乙烯球,得到了金属Al纳米颗粒阵列;采用原子层沉积法,在Al纳米颗粒阵列表面依次沉积氧化铝(Al_2O_3)和氧化锌(ZnO).通过测试Al纳米颗粒阵列的消光谱以及ZnO薄膜的光致发光谱,研究了Al纳米颗粒表面等离激元与ZnO薄膜激子之间的耦合效应.实验结果表明:引入Al纳米颗粒后,在约380 nm位置附近的ZnO近带边发光峰积分强度增强了1.91倍.对Al纳米颗粒表面等离激元增强ZnO光致发光的机理进行探讨.     

用于并行激光直写的连续深浮雕衍射透镜阵列研究

研究了一种用于并行激光直写的连续深浮雕衍射透镜阵列方法.该方法采用连续浮雕衍射透镜阵列替换传统并行激光直写中的物镜阵列,在兼顾系统分辨力基础上,克服了波带片等衍射透镜阵列衍射效率低的缺点|同时因采用深浮雕结构优化环带宽度,可降低阵列的制作难度.针对并行激光直写系统阵列F/#小的特点,在建立连续深浮雕衍射透镜阵列非旁轴近似聚焦模型基础上,设计、制作和测试了波长为441.6 nm,F/#为7.5的连续深浮雕衍射透镜阵阵列.测试结果表明：该阵列的衍射效率优于70%,远高于波带片阵列的40%.