Muravitskaya Alina, Gokarna Anisha, Movsesyan Artur, Kostcheev Sergei, Rumyantseva Anna, Couteau Christophe, Lerondel Gilles, Baudrion Anne-Laure, Gaponenko Sergey, Adam Pierre-Michel
Laboratory Light, Nanomaterials & Nanotechnologies (L2n), CNRS ERL 7004, University of Technology of Troyes, 12 rue Marie Curie, 10004 Troyes Cedex, France.
Nanoscale. 2020 Mar 21;12(11):6394-6402. doi: 10.1039/c9nr09393a. Epub 2020 Mar 6.
The arrangement of plasmonic nanoparticles in a non-symmetrical environment can feature far-field and/or near-field interactions depending on the distance between the objects. In this work, we study the hybridization of three intrinsic plasmonic modes (dipolar, quadrupolar and hexapolar modes) sustained by one elliptical aluminium nanocylinder, as well as behavior of the hybridized modes when the nanoparticles are organized in arrays or when the refractive index of the surrounding medium is changed. The position and the intensity of these hybridized modes were shown to be affected by the near-field and far-field interactions between the nanoparticles. In this work, two hybridized modes were tuned in the UV spectral range to spectrally coincide with the intrinsic interband excitation and emission bands of ZnO nanocrystals. The refractive index of the ZnO nanocrystal layer influences the positions of the plasmonic modes and increases the role of the superstrate medium, which in turn results in the appearance of two separate modes in the small spectral region. Hence, the enhancement of ZnO nanocrystal photoluminescence benefits from the simultaneous excitation and emission enhancements.
在非对称环境中，等离激元纳米颗粒的排列可呈现远场和/或近场相互作用，这取决于物体之间的距离。在这项工作中，我们研究了由一个椭圆形铝纳米柱维持的三种本征等离激元模式（偶极、四极和六极模式）的杂化，以及当纳米颗粒排列成阵列或周围介质的折射率改变时杂化模式的行为。这些杂化模式的位置和强度被证明会受到纳米颗粒之间近场和远场相互作用的影响。在这项工作中，两种杂化模式在紫外光谱范围内被调谐，使其在光谱上与ZnO纳米晶体的本征带间激发和发射带重合。ZnO纳米晶体层的折射率影响等离激元模式的位置，并增加了上层介质的作用，这反过来又导致在小光谱区域出现两种分离的模式。因此，ZnO纳米晶体光致发光的增强得益于同时的激发和发射增强。
