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arXiv 2103.07398physics.opticsphysics.chem-phphysics.comp-phphysics.ins-det
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覆盖金纳米棒二聚体天线中几何诱导增强因子的改善

Geometry-induced enhancement factor improvement in covered-gold-nanorod-dimer antennas

Iván A. Ramos, L. M. León Hilario, María L. Pedano, Andres A. Reynoso

摘要:

发光的缺口金纳米棒二聚体保持表面等离子体激元(SPP),可以通过适当选择几何参数进行工程设计,以增强间隙处的电磁场,从而允许通过表面增强拉曼光谱(SERS)进行分子检测的应用。设想其中间隙中的分子的SERS光谱由电测量补充的混合装置,出现了设计有效几何形状以接触纳米棒而不降低纳米天线的增强因子(EF)的问题,即,SERS光谱的品质因数。在这个框架内,我们从理论上研究的可行性,以制造设计的基础上覆盖金的远距离的间隙区域的二聚体。我们表明,通过调整设计的几何参数,这些系统可以达到增强因子大于在未覆盖的二聚体中实现的最佳效果:即使在纳米棒和覆盖层之间的界面处存在二聚体不对称性和空位,这种至高无上的生存。我们的研究结果表明,远离间隙的几何修改可以提高在间隙的光学响应,从而使这些设备的混合和光学应用。

英文摘要:

Illuminated gapped-gold-nanorod dimers hold surface plasmon polaritons (SPPs) that can be engineered, by an appropriate choice of geometrical parameters, to enhance the electromagnetic field at the gap, allowing applications in molecular detection via surface-enhanced Raman spectroscopy (SERS). Envisioning hybrid devices in which the SERS spectroscopy of molecules in the gap is complemented by electrical measurements, it arises the question of designing efficient geometries to contact the nanorods without decreasing the enhancement factor (EF) of the nanoantenna, i.e., the figure of merit for SERS spectroscopy. Within this framework we theoretically study the feasibility to fabricate designs based on covering with gold the far-from-the-gap areas of the dimer. We show that by tuning the geometrical parameters of the designs these systems can reach enhancement factors larger than the best achieved in the uncovered dimer: this supremacy survives even in the presence of dimer asymmetries and vacancies at the interfaces between the nanorods and the covering layers. Our results show that geometrical modifications away from the gap can improve the optical response at the gap, thus enabling the use of these devices both for hybrid and optical applications.

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。

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