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。     

多种金属/TiO2核壳纳米棒阵列的通用制备方法

使用了一种具有较大通用性的方法制备了金属/二氧化钛(TiO₂)核壳纳米结构. 采用电沉积方法在多孔氧化铝模板(AAO)孔洞中沉积壁厚均一的TiO₂纳米管,TiO₂纳米管的壁厚可以通过沉积时间来控制,而纳米管的直径和长度则由模板孔洞大小和模板厚度决定. 采用这种方法制备的TiO₂纳米管顶端是开放的,而底端连接在电沉积前溅射在AAO模板背面的金膜上. 这种TiO₂纳米管阵列结构适合进行二次电沉积,以它为模板将Pd、Cu、Fe等金属沉积到纳米管中形成核壳纳米棒结构. 这是一种可以用于制备多种金属/TiO₂核壳纳米结构的通用方法,采用这种方法制备的金属/TiO₂核壳纳米棒结构具有填充率高和取向性好的特点,而且它们的壁厚和长度可以通过分别改变两步电沉积的时间来控制.     

AlN纳米线宏观阵列的制备

借助二次模板法成功的合成了AlN纳米线宏观阵列,并进行了表征.主要研究CVD法制备有一定取向,直径均匀的AlN纳米线宏观阵列的过程.通过气相沉积法和利用PS球自组装模板制备了金属纳米颗粒模板;再以模板上的金属纳米颗粒作为催化剂,利用化学气相沉积在模板上合成AlN纳米线宏观阵列.借助SEM,TEM观察所得样品,AlN纳米线阵列面积约为0.3 mm×0.2 mm,直径和长度分布均匀,平均直径约为41 nm,平均长度为1.8 μm左右,分散密度和覆盖率大的六角结构AlN纳米线宏观阵列.得到了可控制备AlN纳米线 关键词： AlN纳米线阵列 模板法 CVD法 SEM     

ZnS纳米棒阵列的结构和光学特性

采用等离子体辅助的低压金属有机化学气相沉积（LP-MOCVD）技术,在没有引入任何金属催化剂的条件下,在c平面的蓝宝石衬底上制备出高取向的ZnS纳米棒阵列。从样品的场发射扫描电镜（SEM）和透射电镜的照片（TEM）中可以看到,获得的ZnS纳米棒具有均一的直径和长度,其直径和长度约为60,400nm;X射线衍射（XRD）和选区电子衍射（SAED）谱指出获得的ZnS纳米棒为单晶的六角结构。此外,在光致发光（PL）谱中还观测到了发光峰位于335nm强的近带边发射。     

银纳米膜的电化学制备方法及性能表征

采用电沉积方法在表面活性剂与电解液的界面上制备了银纳米膜。通过对甲磺酸银体系和硝酸银体系中纳米银膜的电沉积速率及纳米银膜颗粒进行比较发现，相同条件下硝酸银体系得到的纳米膜晶粒粒径比较小，膜的生长速率较快。选定硝酸银体系为电沉积体系。考察了槽压、电解液的浓度和温度及溶液的pH值对制备银纳米膜的影响，确立了制备银纳米膜的最佳工艺条件为硝酸银浓度5mmol/L，槽压4V，pH3.0,硬脂酸的质量浓度0.2g/L。实验表明，最佳工艺条件下制备的银纳米膜晶粒粒径均匀，平均粒径在20nm左右，近似球形。本方法制备的银纳米膜将在非线性光学材料方面得到应用。     

一种新的制备ZnO纳米粒子的方法--阴极电沉积法

用阴极电沉积法制备高质量ZnO纳米薄膜，电沉积采用含有不同浓度的ZnCl2的非水二甲基亚砜溶液做电解液，室温下恒流沉积，得到纳米ZnO薄膜。研究了ZnCl2浓度对薄膜结构和光学性质的影响。沉积薄膜的ZnO粒径尺寸分别为9．8，10．4，14．5nm。随着ZnCl2浓度的增加而增大。薄膜的可见光致发光谱以紫外的自由激子发射为主。研究表明：以浓度为0.03mol/L的ZnCl2电解液制备的ZnO薄膜光学性质最好。     

Co/AAO纳米有序阵列复合结构的光致发光和光吸收特性

以草酸电解液制备的高度有序的纳米级多孔阳极氧化铝(AAO)为模板,采用交流电化学沉积工艺合成了Co/AAO纳米有序阵列复合结构。分别研究了AAO模板和Co/AAO结构的光致发光和光吸收特性。结果表明,AAO模板在350～550nm范围内存在较强的光致发光带,其峰位在395nm处;Co/AAO纳米有序阵列复合结构的光致发射峰位亦在395nm处,且发光峰强度随Co沉积量的增加而迅速减弱。实验发现,Co/AAO纳米有序阵列复合结构的光吸收边从近紫外至近红外的波段范围内发生大幅度红移,最大红移量甚至超过380nm。文章定性分析并解释了Co/AAO纳米有序阵列复合结构吸收边大幅度红移及其光发射峰位不变、而峰强减弱的主要原因。     

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.     

用电爆炸丝法制备纳米粉末及负载型纳米催化剂

目前制备纳米材料的方法很多，其中电爆炸丝法制备纳米粉末材料是20世纪90年代后期发展起来的新型方法，俄罗斯和日本研究人员利用该方法成功制备多种金属和金属化合物纳米粉末。我国吉林大学利用该方法制备了纳米Cu-Zn合金粉末，其粒度分布在30～180nm，平均粒度约85nm。为了探索电爆炸金属丝技术在制备纳米粉末及其相关产品中的应用前景，文中对电爆炸金属丝产生纳米Al2O3和TiO2进行了实验研究，并在此基础上开展了电爆炸金属丝制备负载型纳米催化剂的初步研究。     

模板法交流沉积金纳米线的影响因素

使用交流电沉积在多孔氧化铝模板中制备金纳米线,对交流电沉积时阻挡层厚度、交流电压、交流频率等因素进行了系统的研究和探讨。使用交流电沉积制备出了直径30 nm、长度2.1 m的形貌完好、长度均一的金纳米阵列。结果表明模板的阻挡层厚度能够显著影响金属的沉积电位,是保证沉积顺利进行的重要因素。通过记录、分析不同条件下交流沉积过程中时间-电流曲线来对交流沉积过程进行深入研究并提出相应机理。发现同频率下平台电流值不变,纳米线的长度与交流电压大小成正比,而同电压下沉积的平台电流与交流电频率成正比,这些都与阻挡层的半导体特性有关。     

Synthesis and magnetic properties of ordered barium ferrite nanowire arrays in AAO template

BaFe₁₂O₁₉ nanowire arrays having single magnetic domain size (≤460 nm) in anodic aluminum oxide (AAO) templates were prepared by sol-gel and self-propagating high-temperature synthesis techniques. The diameter of the nanowire arrays is approximately 70 nm and the length is about 2-4 μm. The specimens were characterized using X-ray diffraction, vibrating sample magnetometer, field emission scan electron microscope, atomic force microscopy and microwave vector network analyzer. The magnetic properties of BaFe₁₂O₁₉ nanowire arrays embedded in AAO templates were measured by VSM with a field up to 1274 KA/m at room temperature. The results indicate that the nanowire arrays exhibit large saturation magnetization and high coercivity in the range of 6000 Oe and an obvious magnetic anisotropy with the easy magnetizing axis along the length of the nanowire arrays, probably due to the shape anisotropy and magneto-crystalline anisotropy. Finally the microwave absorption properties of the nanowires were discussed.     

亚波长尺度下混合等离子泄漏模式激光

由于光存在衍射极限,因此传统方法不能实现亚波长尺度下的激光激射.为了打破这一衍射极限,本文设计了金属-介电层-半导体堆叠结构来实现深亚波长尺度下的激光激射,并讨论了相关结构对模式传播的影响.结构设计上,采用低介电常数金属银作为衬底、10?nm厚的LiF作为介电层、具有六边形截面的半导体纳米线ZnO作为高介电常数层,采用...     

碳泡沫衬底上氮化铝纳米线的生长及其光致发光特性研究

为了简化了AlN/C复合泡沫材料的制备流程, 本文采用复分解反应法制备AlN纳米材料, 并通过800℃退火处理使其在碳泡沫衬底上重结晶为六方相AlN纳米线. 通过形貌表征测试, 纳米线为表面光滑的长直形圆柱体, 直径约50 nm, 长度10 μm以上, 在碳微球表面沿[001]方向生长. 同时, 采用VLS生长机理对纳米线的生长进行了解释. 对样品光致发光谱的研究表明, 中心波长423 nm处存在一尖锐发光峰且随温度升高发生明显的红移现象, 系C替N杂质能级跃迁发光所致. 样品在紫光波段具有良好的光致发光特性, 有望应用于光探测器领域.     

Synthesis and magnetic properties of spinel CoFe2O4 nanowire arrays

Spinel CoFe₂O₄ nanowire arrays were synthesized in nanopores of anodic aluminum oxide (AAO) template using aqueous solution of cobalt and iron nitrates as precursor. The precursor was filled into the nanopores by vacuum impregnation. After heat treatment, it transformed to spinel CoFe₂O₄ nanowires. The structure, morphology and magnetic properties of the sample were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The results indicate that the nanowire arrays are compact. And the individual nanowires have a high aspect ratio, which are about 80 nm in diameter and 10 μm in length. The nanowires are polycrystalline spinel phase. Magnetic measurements indicate that the nanowire arrays are nearly magnetic isotropic. The reason is briefly discussed. Moreover, the temperature dependence of the coercive force of the nanowire arrays was studied.     

Study on magnetic property of Fe14Ni86 alloy nanowire array

Ordered Fe₁₄Ni₈₆ alloy nanowire arrays implanted in anodic alumite template (AAT) have been fabricated by electrodepositing the corresponding material into the nanochannels. The wires are 43 nm in diameter and 50 μm in length. Their aspect ratio (ratio of length to diameter) is more than 1000, which results in distinctive magnetic anisotropy. The easy magnetization axis of this system is perpendicular to the membrane. Enhanced coercivity (about 769 Oe) and remanent magnetization up to 70% of the saturation magnetization have been observed. We also studied angular dependent coercivities of the Fe₁₄Ni₈₆ alloy nanowire arrays and found that they fit well with the chain-of-sphere combined model of uniform rotation and non-symmetric fanning.     

ANSYS仿真激光切割氧化锌纳米线

 以脉冲高斯激光为光源,直径在500 nm～1 000 nm、长度10 μm的一维氧化锌材料为对象,采用有限元分析软件ANSYS建立了激光切割氧化锌纳米线的热力学仿真模型,并采用生死单元技术对超过熔点的单元进行处理,得到不同激光工作参数和氧化锌纳米线直径下的温度分布场和切割形貌。讨论了纳米线直径和聚焦光斑相对纳米线的位移对切割的影响,纳米线直径越大允许的激光离焦量越小;当无离焦或负离焦较小时,切割纳米线产生的形貌较为理想。     

Facile route to high-density, ordered ZnO nanowire arrays and their photoluminescence properties

A simple template-directed wet chemistry route based on traditional thermal decomposition technique has been developed for the preparation of high-density, ordered ZnO nanowire arrays. The fabrication was performed at relative low temperature without involving complex procedures, sophisticated equipment and rigorous experiment conditions, thereby providing a straightforward and mild method to produce metal/metal oxide ordered nanostructures. The nanowire array system was evaluated by SEM, XRD, TEM and PL. A stable luminescence at 425 nm was present.     

Helical gold nanotube synthesized at 150 K

Gold nanowires were synthesized at 150 K by electron beam thinning of a gold thin foil in an UHV electron microscope. The gold nanowires were found to have a helical multishell structure (HMS). One particular nanowire, which was thinner than the 7-1 HMS nanowire, was found to have a tubular structure. The gold single wall nanotube is composed of five atomic rows that coil about the tube axis. The diameter was 0.4 nm and the pitch was 11 nm. The stability of the (5,3) nanotube was discussed in terms of the shear deformation of the triangular network of gold atoms.     

Template synthesis of single-crystal Cu nanowire arrays by electrodeposition

Cu nanowire arrays have been synthesized using potentiostatic electrodeposition within the confined nanochannels of a porous anodic alumina membrane. The Cu nanowire arrays and the individual nanowires have been characterized using SEM, TEM, SAED, HREM and XRD. Investigation results reveal that the Cu nanowire arrays having high wire packing densities are highly ordered over large areas. The individual Cu nanowires (diameter ∼60 nm) were single-crystal and found to be dense and continuous with uniform diameters throughout their entire length. An optimum ECD condition (at lower overpotentials) for the synthesis of single-crystal Cu nanowires was also discussed. Received: 19 April 2001 / Accepted: 28 April 2001 / Published online: 20 June 2001     

Magnetic domain structure in small diameter magnetic nanowire arrays

Fe_0.3Co_0.7 alloy nanowire arrays were prepared by ac electrodepositing Fe²⁺ and Co²⁺ into a porous anodic aluminum oxide (PAO) template with diameter about 50 nm. The surface of the samples were polished by 100 nm diamond particle then chemical polishing to give a very smooth surface (below ±10 nm/μm²). The morphology properties were characterized by SEM and AFM. The bulk magnetic properties and domain structure of nanowire arrays were investigated by VSM and MFM respectively. We found that such alloy arrays showed strong perpendicular magnetic anisotropy with easy axis parallel to nanowire arrays. Each nanowire was in single domain structure with several opposite single domains surrounding it. Additionally, we investigated the domain structure with a variable external magnetic field applied parallel to the nanowire arrays. The MFM results showed a good agreement with our magnetic hysteresis loop.