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表面等离激元是束缚在金属—介质交界面上的一种电磁波模式,可突破衍射极限,被认为是下一代集成光子回路最有希望的信息载体。基于我们的研究工作,就几种表面等离激元金属狭缝结构的原理和应用做了简单概述。利用法布里-波罗谐振腔、法诺共振、多模干涉等光学效应,这些金属狭缝结构可对表面等离激元的传输行为进行有效地调控。在理论上和实验上,利用金属狭缝结构实现了亚波长表面等离激元单向激发器、亚微米宽带单向激发器、亚微米分束器、超紧凑纳米聚焦器件和亚微米全光开关等纳米光子器件。这些纳米光子器件在纳米集成光学中具有重要应用。 相似文献
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等离激元纳米孔将等离激元天线与固体纳米孔结合,可限制待测物路径,并将入射光能聚集至路径中产生热点,从而增强场与待测物质的相互作用,在纳米尺度范围内实现高灵敏度检测,近年来已被广泛应用于单分子检测研究。本文概述了几种典型等离激元纳米孔结构及其场增强效果;分析讨论了4种目前常用的基于等离激元纳米孔的高灵敏度检测技术及其特点,包括荧光检测、表面拉曼增强光谱、表面等离激元共振位移传感以及光电结合方法;综述了等离激元纳米孔在脱氧核糖核酸(DNA)、蛋白质、肽等单分子光学检测方面的应用进展及典型成果;讨论和展望了等离激元纳米孔的未来研究趋势以及面临的机遇和挑战。 相似文献
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光电探测器作为航空航天、深空探测和环境监测等领域的核心器件之一,具有重要的科学研究和实用价值。表面等离激元具有可突破光学衍射极限、实现纳米聚焦的性质,为光电探测器的性能提升提供了全新的技术手段,是近年来光电探测增效研究领域的热点之一。文中围绕表面等离激元纳米结构增效的光电探测器研究展开综述,首先介绍了各类表面等离激元纳米结构的物理特性,主要包括局域表面等离激元结构和传导型的表面等离极化激元结构,以及由表面等离激元金属和半导体材料构成的异质结构;然后重点从探测器性能、探测原理和工艺方法等角度,介绍了等离激元纳米结构增强的光电探测器的研究进展;最后对表面等离激元纳米结构增效的光电探测器及其在未来面临的挑战进行了总结和展望。 相似文献
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银纳米线可以承载传播的表面等离激元,纳米片可以产生局域的表面等离激元,二者形成的耦合结构不但可以将传播光场耦合为局域增强光场,还可以调控光场的偏振态等性质,为纳米光调控提供新的自由度。本团队构建了银纳米线-三角片耦合结构,并发现耦合结构的发射偏振与纳米线-三角片的耦合方式有关:当三角片与纳米线之间是“线”接触耦合时,耦合结构的发射偏振随着激发偏振的旋转而旋转;当二者是“点”接触耦合时,无论激发偏振如何变化,发射偏振角度几乎保持160°不变。进一步,利用时域有限差分法验证了出射偏振对入射偏振的依赖特性。通过计算自由电流密度体积分揭示了纳米线中传播的表面等离激元模式与银纳米线-三角片耦合模式的转化机制,以及不同表面等离激元模式的叠加对发射偏振的调控。这些发现为纳米尺度上的光调控以及在纳米尺度上构建纳米光子器件提供了更多灵活性。 相似文献
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等离激元激发产生的热载流子可以有效驱动化学反应的发生,进而实现太阳能的高效利用。合理设计等离激元金属纳米结构是提高热载流子产生与注入效率,进而实现超宽光谱吸收和高效能量转换的有效途径。本课题组制备了具有高密度尖端的等离激元纳米海胆颗粒,并构建了金属半导体复合结构的光阳极,通过测试光阳极微反应区的光电流响应评估了热载流子的产生与注入效率。结果表明:纳米海胆结构具有优异的光电催化活性,其尖端处的大量热点促进了热载流子的产生,金属与半导体间丰富的界面接触增加了热载流子的注入机会。该设计为热载流子的高效激发与提取提供了参考。 相似文献
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Hong‐Mei Gong Li Zhou Xiong‐Rui Su Si Xiao Shao‐Ding Liu Qu‐Quan Wang 《Advanced functional materials》2009,19(2):298-303
The chemical growth of silver nanorings that possess singly twinned crystals and a circular cross section via a reductive reaction solution is reported. The wire and ring diameters of the synthesized nanorings are in the ranges 80–200 nm and 4.5–18.0 μm, respectively. By lighting up the multipolar dark plasmons with slanted illumination, the silver nanoring exhibits unique focused scattering and large local‐field enhancement. We also demonstrate strong exciton–plasmon interactions between a monolayer of CdSe/ZnS semiconductor quantum dots and a single silver antenna‐like nanoring (nanoantenna) at the “hot spots” located at the cross points of the incident plane and nanoring; the position of these spots are tunable by adjusting the incidence angle of illumination. The tunable plasmonic behavior of the silver nanorings could find applications as optical nanoantennae or plasmonic nanocavities. 相似文献
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Fano共振效应拥有独特的局域场增强效果,在表面增强相干反斯托克斯拉曼散射中,不同波长局域场增强空间位置相同的结构结合Fano共振效应,可以实现混合频率共振模式,使得表面增强相干反斯托克斯拉曼散射总的增强因子得到大幅度提高。采用FDTD软件系统研究了对称的交叉蝴蝶结Au纳米结构的Fano共振效应,该效应使得交叉蝴蝶结结构中心位置附近的电场强度得到大幅度的增强,把该结构应用到表面增强相干反斯托克斯拉曼散射中,可以使表面增强相干反斯托克斯拉曼散射信号的增强因子高达1013,达到单分子检测的水平。 相似文献
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以多元金属纳米薄膜(金、银)为基底,利用飞秒激光加工技术制备得到多元等离子体纳米结构,并研究了其局域表面等离子体共振效应(Local Surface Plasmon Resonance,LSPR)和表面增强拉曼散射(Surface Enhanced Raman Scattering,SERS)性能。利用时域有限差分(Finite Difference Time Domain,FDTD)软件模拟了不同情况下(单层金膜、金银双层金属薄膜的平面以及阵列结构)的电场分布情况。根据仿真结果,相较于平面金属膜来说,飞秒激光制备的微纳结构阵列附近区域产生电磁场增强,集中在结构边缘处,且其强度变化与预期结果基本保持一致。此外,使用浓度为10-4 M和10-6 M的罗丹明(R6G)溶液进行SERS性能测试。测试的结果表明,单层平面金膜基本没有SERS峰值信号出现,而单层金膜上制备的等离子体纳米结构附近出现峰值信号,双层金属薄膜上制备的等离子体纳米结构展现出更高的SERS峰值信号。多元金属等离子体纳米结构展示出更强的局域表面等离子体共振效应,从而在表面增强拉曼散射、光催化、生物传感等领域具有广泛的应用。 相似文献
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Rational Assembly of Optoplasmonic Hetero‐nanoparticle Arrays with Tunable Photonic–Plasmonic Resonances 下载免费PDF全文
Metallic and dielectric nanoparticles (NPs) have synergistic electromagnetic properties but their positioning into morphologically defined hybrid arrays with novel optical properties still poses significant challenges. A template‐guided self‐assembly strategy is introduced for the positioning of metallic and dielectric NPs at pre‐defined lattice sites. The chemical assembly approach facilitates the fabrication of clusters of metallic NPs with interparticle separations of only a few nanometers in a landscape of dielectric NPs positioned hundreds of nanometers apart. This approach is used to generate two‐dimensional interdigitated arrays of 250 nm diameter TiO2 NPs and clusters of electromagnetically strongly coupled 60 nm Au NPs. The morphology‐dependent near‐ and far‐field responses of the resulting multiscale optoplasmonic arrays are analyzed in detail. Elastic and inelastic scattering spectroscopy in combination with electromagnetic simulations reveal that optoplasmonic arrays sustain delocalized photonic–plasmonic modes that achieve a cascaded E‐field enhancement in the gap junctions of the Au NP clusters and simultaneously increase the E‐field intensity throughout the entire array. 相似文献
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Khang June Lee Daewon Kim Byung Chul Jang Da‐Jin Kim Hamin Park Dae Yool Jung Woonggi Hong Tae Keun Kim Yang‐Kyu Choi Sung‐Yool Choi 《Advanced functional materials》2016,26(28):5093-5101
The plasmonic coupling, the enhanced electromagnetic field occurring through a uniform and small separation between metallic particles, is required for better application to localized surface plasmon resonance. Graphene has been studied as a good spacer candidate because of its precise controllability at subnanoscale. Here, the enhancement of plasmonic coupling among metallic nanoparticles (NPs) uniformly spread out on both sides of a graphene spacer is experimentally and simulatively investigated. Additionally, the post‐evaporated flat structure is rippled along one direction to reduce the separation between nanoparticles. As the amount of rippling increases, the enhancement factor (EF) of the plasmonic coupling increases almost linearly or quadratically depending on the size of nanoparticles. Such a highly rippled nanostructure is believed to not only increase the plasmonic coupling in either side of the spacer but lead to a higher density of “hot spots” through the spacer gap also. The observed EFs of a structure with the MLG spacer are consistent with the simulation results obtained from the classical electrodynamics. On the other hand, the SLG case appears to be inconsistent with such a classical approach, indicating that the plasmon tunneling through the thin barrier is prevalent in the case of the SLG spacer. 相似文献
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Zelio Fusco Mohsen Rahmani Renheng Bo Thanh Tran‐Phu Mark Lockrey Nunzio Motta Dragomir Neshev Antonio Tricoli 《Advanced functional materials》2019,29(2)
Localized surface plasmon resonance (LSPR) devices based on resonant metallic metasurfaces have shown disruptive potential for many applications including biosensing and photocatalysis. Despite significant progress, highly performing Au plasmonic nanotextures often suffer of suboptimal electric field enhancement, due to damping effects in multicrystalline domains. Fabricating well‐defined Au nanocrystals over large surfaces is very challenging, and usually requires time‐intensive multi‐step processes. Here, presented are first insights on the large‐scale self‐assembly of monocrystalline Au nano‐islands with tunable size and separation, and their application as efficient LSPR surfaces. Highly homogeneous centimeter‐sized Au metasurfaces are fabricated by one‐step deposition and in situ coalescence of hot nanoparticle aerosols into a discontinuous monolayer of highly faceted monocrystals. First insights on the mechanisms driving the high‐temperature synthesis of these highly faceted Au nanotextures are obtained by molecular dynamic and detailed experimental investigation of their growth kinetics. Notably, these metasurfaces demonstrat high‐quality and tunable LSPR, enabling the fabrication of highly performing optical gas molecule sensors detecting down to 3 × 10?6 variations in refractive index at room temperature. It is believed that these findings provide a rapid, low‐cost nanofabrication tool for the engineering of highly homogenous Au metasurfaces for large‐scale LSPR devices with application ranging from ultrasensitive optical gas sensors to photocatalytic macroreactors. 相似文献
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宽谱响应光电探测器在图像传感和光通信等领域应用前景广阔。金属微纳结构通过激发表面等离激元共振效应可高效产生热载流子,将它们与宽带隙半导体构成异质结构,便可利用热载流子开发出低成本宽谱响应光电探测器。研究设计了一种基于Au/TiO2复合纳米结构的热电子光电探测器。其中TiO2层经退火后形成尺度约为百纳米的凹凸结构,Au纳米颗粒层与用作电极的保形Au膜共同组成了激发表面等离激元共振的纳米结构。由于Au/TiO2复合纳米结构的协同作用,该器件在400~900 nm范围内具有宽谱光吸收性能,器件的平均光吸收效率为33.84%。在此基础上,该器件能够探测TiO2本征吸收波段以外的入射光子。例如,在600 nm波长处,器件的响应率为9.67μA/W,线性动态范围为60 dB,器件的上升/下降响应速度分别为1.6 ms和1.5 ms。此外,利用有限元法进行了仿真计算,通过电场分布图验证了Au/TiO2复合纳米结构中所激发的丰富表面等离激元共振效应是其实现宽谱高效探测的原因所在。 相似文献
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Jincy Jose Luke R. Jordan Timothy W. Johnson Si Hoon Lee Nathan J. Wittenberg Sang‐Hyun Oh 《Advanced functional materials》2013,23(22):2812-2820
The ability to precisely control the topography, roughness, and chemical properties of metallic nanostructures is crucial for applications in plasmonics, nanofluidics, electronics, and biosensing. Here a simple method to produce embedded nanoplasmonic devices that can generate tunable plasmonic fields on ultraflat surfaces is demonstrated. Using a template‐stripping technique, isolated metallic nanodisks and wires are embedded in optical epoxy, which is capped with a thin silica overlayer using atomic layer deposition. The top silica surface is topographically flat and laterally homogeneous, providing a uniform, high‐quality biocompatible substrate, while the nanoplasmonic architecture hidden underneath creates a tunable plasmonic landscape for optical imaging and sensing. The localized surface plasmon resonance of gold nanodisks embedded underneath flat silica films is used for real‐time kinetic sensing of the formation of a supported lipid bilayer and subsequent receptor‐ligand binding. Gold nanodisks can also be embedded in elastomeric materials, which can be peeled off the substrate to create flexible plasmonic membranes that conform to non‐planar surfaces. 相似文献
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3D Aluminum Hybrid Plasmonic Nanostructures with Large Areas of Dense Hot Spots and Long‐Term Stability 下载免费PDF全文
Xi‐Mei Li Ming‐Hai Bi Lan Cui Yu‐Zhu Zhou Xi‐Wen Du Shi‐Zhang Qiao Jing Yang 《Advanced functional materials》2017,27(10)
Plasmonic materials possessing dense hot spots with high field enhancement over a large area are highly desirable for ultrasensitive biochemical sensing and efficient solar energy conversion; particularly those based on low‐cost noncoinage metals with high natural abundance are of considerable practical significance. Here, 3D aluminum hybrid nanostructures (3D‐Al‐HNSs) with high density of plasmonic hot spots across a large scale are fabricated via a highly efficient and scalable nonlithographic method, i.e., millisecond‐laser‐direct‐writing in liquid nitrogen. The nanosized alumina interlayer induces intense and dual plasmonic resonance couplings between adjacent Al nanoparticles with bimodal size distribution within each of the hybrid assemblies, leading to remarkably elevated localized electric fields (or hot spots) accessible to the analytes or reactants. The 3D‐stacked nanostructure substantially raises the hot spot density, giving rise to plasmon‐enhanced light harvesting from deep UV to the visible, strong enhancement of Raman signals, and a very low limit of detection outperforming reported Al nanostructures, and even comparable to the noble metals. Combined with the long‐term stability and good reproducibility, the 3D‐Al‐HNSs hold promise as a robust low‐cost plasmonic material for applications in plasmon‐enhanced spectroscopic sensing and light harvesting. 相似文献