Refractive index mediated plasmon hybridization in an array of aluminium nanoparticles

• Main Authors: Muravitskaya, Alina, Gokarna, Anisha, Movsesyan, Artur, Kostcheev, Sergei, Rumyantseva, Anna, Couteau, Christophe, Lerondel, Gilles, Baudrion, Anne-Laure, Gaponenko, Sergey, Adam, Pierre Michel
• Format: Journal Article
• Language: English
• Published: 21-02-2020
• Subjects: Physics - Optics
• DOI: 10.48550/arxiv.2002.09337

The arrangement of plasmonic nanoparticles in a non-symmetrical environment
can feature the 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 array 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 nanocrystals 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 nanocrystals photoluminescence benefits from the
simultaneous excitation and emission enhancements.