Plasmonic Au islands on polymer nanopillars
Plasmonic Au islands on polymer nanopillars
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DOI：
10.1088/0957-4484/22/29/295303
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发表时间：
2011-07-22
期刊：
影响因子：
3.5
通讯作者：
Crego-Calama, Mercedes
中科院分区：
文献类型：
--
作者：
Knoben, Wout;Brongersma, Sywert H.;Crego-Calama, Mercedes
通过将等离子体金属粒子放置在柱子上而不是平面衬底上，可以提高局域化表面等离子体共振传感器的折射率灵敏度。本文描述了一种简单而通用的胶体光刻方法，用于在聚合物纳米柱上制备等离子体Au岛。通过改变初始聚合物膜的厚度来控制柱子的高度。随着柱高的增加，Au岛的吸收光谱蓝移。这是由于岛屿周围的有效折射率降低所致。对于高于约40 nm的柱子，没有观察到进一步的蓝移，这与岛屿周围电磁场的衰减长度一致。柱状支撑的Au岛也被制作在柔性箔上，展示了这里描述的方法在柔性等离子体衬底制备中的潜力。讨论了该方法和使用聚合物作为柱子材料的优点和局限性。
The refractive index sensitivity of localized surface plasmon resonance sensors can be improved by placing the plasmonic metal particles on pillars instead of on a planar substrate. In this paper, a simple and versatile colloidal lithography method for the fabrication of plasmonic Au islands on top of polymer nanopillars is described. The pillar height is controlled by varying the thickness of the initial polymer film. An increased pillar height results in a blue shift of the absorption spectrum of the Au islands. This is explained by a decreased effective refractive index around the islands. For pillars higher than approximately 40 nm no further blue shift is observed, in agreement with the decay length of the electromagnetic field around the islands. Pillar-supported Au islands were also fabricated on a flexible foil, demonstrating the potential of the method described here for the fabrication of flexible plasmonic substrates. Benefits and limitations of the method and of using polymers as the pillar material are discussed.