Gold, Platinum, and Aluminum Nanodisk Plasmons: Material Independence, Subradiance, and Damping Mechanisms
Journal article, 2011

Localized surface plasmon resonances (LSPR) are collective electronic excitations in metallic nanoparticles. The LSPR spectral peak position, as a function of nanoparticle size and material, is known to depend primarily on dynamic depolarization and electron structure related effects. The former gives rise to the well-known spectral red shift with increasing nanoparticle size. A corresponding understanding of the LSPR spectral line width for a wide range of nanoparticle sizes. and different metals does, however, not exist. In this work, the radiative and nonradiative damping contributions to the LSPR line width over a broad nanoparticle size range (40-500 nm). for a. selection of three metals with fundamentally different bulk dielectric properties (Au, Pt, and Al) are explored experimentally and theoretically. Excellent agreement was obtained between the observed experimental trends and the predictions based on electrostatic spheroid theory (MLWA), and the obtained results were successfully related to the specific band structure of the respective metal. Moreover, for the first time, a clear transition from a radiation damping dominated to a quenched radiation damping regime (subradiance) in large nanoparticles was observed and probed by varying the electron density through appropriate material choice. To minimize inhomogeneous broadening (commonly present in ensemble-based spectroscopic measurements), a novel, electron-beam lithography (EBL)-based nanofabrication method was developed. The method generates large-area 2D patterns of randomly distributed, nanodisks with well-defined size and shape, narrow size. distribution, and tunable (minimum) interparticle distance. In order to minimize particle-particle coupling effects, sparse patterns with a large interparticle distance (center-to-center >= 6 particle diameters) were considered.

plasmon energy

nanoshells

line width

resonance

particles

platinum

nanosphere lithography

enhancement

localized surface plasmon resonance

field

subradiance

gold

material independence

optical-properties

depolarization

metal nanoparticles

pd

aluminum

Author

Igor Zoric

Chalmers, Applied Physics, Chemical Physics

Michael Zäch

Chalmers, Applied Physics, Chemical Physics

Bengt Herbert Kasemo

Chalmers, Applied Physics, Chemical Physics

Christoph Langhammer

Chalmers, Applied Physics, Chemical Physics

ACS Nano

1936-0851 (ISSN) 1936-086X (eISSN)

Vol. 5 4 2535-2546

Subject Categories

Materials Engineering

Chemical Sciences

DOI

10.1021/nn102166t

More information

Created

10/7/2017