【作者】 侯岩雪；

【导师】 井西利； 徐红星；

【作者基本信息】 燕山大学 ， 凝聚态物理， 2012， 博士

【摘要】 基于金属纳米结构的表面等离激元光子学的研究是目前很活跃的一个研究领域，在此基础上发展起来的表面增强光谱技术和表面等离激元共振传感技术已经在众多领域得到了深入的研究和广泛的应用，表面等离激元波导在光电子集成器件方面也存在巨大的应用潜力。本论文的研究工作主要是在合成银纳米结构的基础上展开的，对纳米结构的表面拉曼散射光谱、银纳米线波导及其核壳结构的表面等离激元传播性质和远程激发表面光化学反应进行了研究。首先，本文利用化学上多元醇还原硝酸银的方法来合成银纳米颗粒。通过优化实验条件，控制反应物的浓度、反应速度和反应时间，合成了形状均匀的银纳米球、银纳米米和银纳米线等低维银纳米结构。并利用溶胶-凝胶法制备了厚度均匀的银纳米球和银纳米线的二氧化硅核壳结构。其次，本文研究了二氧化硅壳层对银纳米线波导传播性质的影响。通过在银纳米线及其核壳结构上铺上均匀的荧光分子，并测量纳米线上不同位置的荧光分子被激发后在出射端的发射光强的方法，给出光强相对激发位置的函数关系，再通过数据拟合得到不同壳层厚度的银纳米线上表面等离激元的传播长度。结果表明二氧化硅壳层提高了银纳米线对电磁场的空间限制作用。同时，对于介质折射率较小的玻璃基底，二氧化硅壳层的存在使银纳米线上表面等离激元的传播距离有所减小，而对于介质折射率较大的硅基底，二氧化硅壳层则增加了银纳米线上表面等离激元的传播距离。然后，本文提出并研究了利用银纳米线波导来研究远程激发偏振依赖的表面光化学反应。通过照射银纳米线的一端来激发传播的表面等离激元，表面等离激元能够沿着银纳米线进行有效传播。传播过程中会在不连续点被以光子的形式耦合出来，如，银纳米线的末端、存在银纳米颗粒或其他银纳米线的位置。本文通过原位测量银纳米颗粒-银纳米线体系和银纳米线交叉体系的间隙内分子的表面增强拉曼散射光谱，证明局域电场增强效应引发了分子的表面光化学反应。最后，本文利用铝材料在紫外区域的表面等离激元共振性质，采用含时密度泛函理论研究了蒽醌分子的铝3-蒽醌-铝3结模型的深紫外针尖共振增强拉曼散射的化学增强机制，计算结果显示在铝的表面等离激元作用下共振增强拉曼散射信号强度与正常拉曼散射信号强度相比有七个数量级的提高。更多还原

【Abstract】 The plasmonics has recently been a very active research field based on the variousmetal nanostructures. The technologies of surface-enhanced Raman scattering (SERS)and surface plasmon resonance (SPR) have been studied deeply and applied widely inmany fields. Plasmonic waveguide also possess great potential applications for nanooptoelectronic integration. The work of this dissertation is carried out based on thesynthesis of the silver nanostructures. The surface Raman scattering spectra ofnanostructures and the properties of the propagating surface plasmon polaritons (SPPs)on silver nanowires and Ag-SiO2core-shell nanowires are investigated deeply in thisdissertation. The remote excitation polarization-dependent surface photochemicalreaction by plasmonic waveguide is also studied.First, the silver nanostructures are synthesized by chemically reducing AgNO3withpolyol in this dissertation. The low dimensional uniform Ag nanostructures, such as Agnanospheres and Ag nanowires and Ag nanorices, are obtained under optimal experimentconditions by controling the reactionants concentration, reaction time and speed. Thesilica core shell structure of the silver nanospheres and nanowires are also fabricated bythe sol-gel method.Second, the impact of silica layer on the propagating properties of Ag namowirewaveguide is investigated. The emitting intensity from the end of nanowire is measuredthrough exciting the fluorescent molecules localed on different position of the nanowire.The propagation lengths of surface plasmon polaritons on silver nanowires with differentthickness silica layers can be obtained by linear fitting according to the function ofintensity as the excitation point. The result indicates that the Ag-SiO2core-shellnanowires confine the electromagnetic field stronger than bare Ag nanowire. For glasssubstrate with small refractive index, the propagation lengths of SPPs on Ag-SiO2core-shell nanowires are shorter than that of bare silver nanowires with the samediameter, while they are longer for the silicon substrate with big refractive index.Next, it is proposed and researched that the polarization-dependent surface photochemical reaction can be excited remotely by plasmonic waveguide. SPPs aregenerated at the end of a silver nanowire by incidence light, and propagate efficientlyalong the nanowire. It can be coupled out in photons at the discontinuities of the wirewith nanoparticles or another nanowire as nanoantenna. The remote excitationpolarization-dependent SERS spectra obtained experimentally in the nanogaps of thesystems of nano particles-wire and crossing nanowires reveal the occurrence of surfacecatalytic reaction.Last, the chemical enhancement mechanisms on deep ultraviolet tip-enhancedRaman scattering spectra of anthraquinone in Al3-anthraquinone-Al3junction are studiedwith time dependent density functional theory for plasmon resonance properties ofAluminum in UV range. The results reveal that the Raman spectrum is resonance Ramanscattering, and chemical enhancement is on the order of 107.更多还原