Institute of Physical Chemistry and Polymer Physics, Leibniz-Institut für Polymerforschung Dresden e.V. , Hohe Str. 6, 01069 Dresden, Germany.
Physical Chemistry II, University of Bayreuth , Universitätsstr. 30, 95447 Bayreuth, Germany.
ACS Appl Mater Interfaces. 2018 Jan 24;10(3):3133-3141. doi: 10.1021/acsami.7b16941. Epub 2018 Jan 11.
We investigate the plasmonic coupling of metallic nanoparticles with continuous metal films by studying the effect of the particle-to-film distance, cavity geometry, and particle size. To efficiently screen these parameters, we fabricated a particle-to-film-coupled functional nanostructure for which the particle size and distance vary. We use gold-core/poly(N-isopropylacrylamide)-shell nanoparticles to self-assemble a monolayer of well-separated plasmonic particles, introduce a gradient in the nanoparticle size by an overgrowth process, and finally add a coupling metal film by evaporation. These assemblies are characterized using surface probing and optical methods to show localized magnetic and electric field enhancement. The results are in agreement with finite-difference time-domain modeling methods and calculations of the effective permeability and permittivity. Finally, we provide a proof of concept for dynamic tuning of the cavity size by swelling of the hydrogel layer. Thus, the tunability of the coupled resonance and the macroscopic self-assembly technique provides access to a cost-efficient library for magnetic and electric resonances.
我们通过研究粒子到薄膜的距离、腔体几何形状和粒子大小来研究金属纳米粒子与连续金属膜的等离子体耦合。为了有效地筛选这些参数，我们制造了一种具有粒子尺寸和距离变化的粒子到薄膜耦合功能纳米结构。我们使用金核/聚（N-异丙基丙烯酰胺）壳纳米粒子自组装单层分离良好的等离子体粒子，通过过度生长过程引入纳米粒子尺寸的梯度，最后通过蒸发添加耦合金属膜。使用表面探测和光学方法对这些组件进行了表征，以显示局部磁场和电场增强。结果与有限差分时域建模方法以及有效磁导率和介电常数的计算一致。最后，我们通过水凝胶层的溶胀提供了对腔尺寸进行动态调谐的概念验证。因此，耦合共振的可调谐性和宏观自组装技术为磁和电共振提供了一种具有成本效益的库。
