Absorption Enhancement in Lossy Transition Metal Elements of Plasmonic Nanosandwiches
Artikel i vetenskaplig tidskrift, 2012

Combination of catalytically active transition metals and surface plasmons offers a promising way to drive chemical reactions by converting incident visible light into energetic electron-hole pairs acting as a mediator. In such a reaction enhancement scheme, the conversion efficiency is dependent on light absorption in the metal. Hence, increasing absorption in the plasmonic structure is expected to increase generation of electron-hole pairs and, consequently, the reaction rate. Furthermore, the abundance of energetic electrons might facilitate new reaction pathways. In this work we discuss optical properties of homo- and heterometallic plasmonic nanosandwiches consisting of two parallel disks made of gold and palladium. We show how near-field coupling between the sandwich elements can be used to enhance absorption in one of them. The limits of this enhancement are investigated using finite-difference time-domain simulations. Physical insight is gained through a simple coupled dipole analysis of the nanostructure. For small palladium disks (compared to the gold disk), total absorption enhancement integrated over the near visible solar AM 1.5 spectrum is 8-fold, while for large palladium disks, similar in size to the gold one, it exceeds three.

single

surface

discrete-dipole approximation

silver nanoparticles

nanostructures

optical-constants

resonance

particles

real-time

perfect absorber

Författare

Tomasz Antosiewicz

Chalmers, Teknisk fysik, Kondenserade materiens teori

Peter Apell

Chalmers, Teknisk fysik, Kondenserade materiens teori

Carl Wadell

Chalmers, Teknisk fysik, Kemisk fysik

Christoph Langhammer

Chalmers, Teknisk fysik, Kemisk fysik

Journal of Physical Chemistry C

1932-7447 (ISSN) 1932-7455 (eISSN)

Vol. 116 38 20522-20529

Ämneskategorier

Annan teknik

DOI

10.1021/jp306541n