arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0907.5451cond-mat.mes-hall
收藏

银章鱼的等离子体共振和热点

Plasmonic resonances and hot spots in Ag octopods

Ivan I. Naumov, Zhiyong Li, Alexander M. Bratkovsky

摘要:

新型的等离子体纳米粒子-银八脚体,可以合成各种形状-已被证明显示出灵活的光学响应使用离散偶极子近似。章鱼在光学(可见光,IR)波长下显示出复杂的行为,具有三个主要的共振,可以调谐到期望的响应,这使得它们特别有吸引力地用于例如高性能表面增强拉曼(SERS)检测器。激发的共振模式强烈依赖于恒星的几何参数,而依赖于他们的方向相对于入射辐射是温和的,由于立方对称性。与入射场相比,场“热点”形成有高达50倍的局部场增强。它们通常位于臂之间的表面,并且可以是“电”和“磁”的。虽然前者对于SERS是最重要的,但后者可以通过在其附近捕获磁性纳米颗粒来识别。结果与可用的数据非常一致,并且可以用作纳米颗粒的“形状光谱学”的类型。

英文摘要:

New type of plasmonic nanoparticles - silver octopods that can be synthesized with a variety of shapes - have been demonstrated to show versatile optical response using the discrete dipole approximation. The octopods show a complex behavior at optical (visible, IR) wavelengths, with three major resonances that can be tuned up to a desired response that makes them especially attractive to use in e.g. high-performance surface enhanced Raman (SERS) detectors. The excited resonant modes strongly depend on the geometrical parameters of the stars, while dependence on their orientation with respect to an incident radiation is moderate, owing to cubic symmetry. The field "hot spots" are formed with the local field enhancement up to 50 times compared to an incident field. They are usually localized at the surface between the arms and may be both "electric" and "magnetic". While the former are of primary importance for SERS, the latter may be identified by trapping magnetic nanoparticles in their vicinity. The results are in very good agreement with the data where available and may be used as a type of a "shape spectroscopy" for the nanoparticles.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑