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Author Sadeghi, S. M. ♦ Wing, W. J. ♦ Campbell, Q.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY ♦ AIR ♦ ASYMMETRY ♦ DIELECTRIC MATERIALS ♦ GLASS ♦ GOLD ♦ LAYERS ♦ PEAKS ♦ QUANTUM DOTS ♦ RED SHIFT ♦ REFRACTIVE INDEX ♦ SEMICONDUCTOR MATERIALS ♦ SUBSTRATES ♦ THICKNESS ♦ TWO-DIMENSIONAL CALCULATIONS ♦ WAVELENGTHS
Abstract We study plasmonic lattice modes in two dimensional arrays of large metallic nanodisks in strongly inhomogeneous environments with controlled dielectric asymmetries. This is done within the two limits of positive (air/substrate) and negative (Si/substrate) asymmetries. In the former, the nanodisks are exposed to air, while in the latter, they are fully embedded in a dielectric material with a refractive index much higher than that of the glass substrate (Si). Our results show that in the air/substrate limit, the arrays can mainly support two distinct visible and infrared peaks associated with the optical coupling of multipolar plasmonic resonances of nanodisks in air and substrate (normal modes). As the nanodisks are gradually embedded in Si, i.e., going from the positive to negative asymmetry limit, the visible peak undergoes more than 200 nm red shift without significant mode degradation. Our results show that as this transition happens, a third peak (anomalous mode) becomes dominant. The amplitude and wavelength of this peak increase quadratically with the thickness of the Si layer, indicating formation of a unique collective mode. We study the impact of this mode on the emission semiconductor quantum dots, demonstrating they become much brighter as the result of the long-reach plasmonic fields of the nanodisks when the arrays are in this mode.
ISSN 00218979
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-03-21
Publisher Place United States
Journal Journal of Applied Physics
Volume Number 119
Issue Number 11


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