Near-Field FEM Simulations: A Vital Tool for Studying Silver-Based Plasmonic Systems

R. Asapu [1], S. W. Verbruggen [2], N. Claes [3], S. Bals [3], S. Denys [1], S. Lenaerts [1],
[1] Department of Bioscience Engineering, DuEL Research Group, University of Antwerp, Antwerp, Belgium
[2] Department of Bioscience Engineering, DuEL Research Group, University of Antwerp, Antwerp, Belgium; Center for Surface Chemistry and Catalysis, KU Leuven, Leuven, Belgium
[3] Department of Physics, EMAT Research Group, University of Antwerp, Antwerp, Belgium
Published in 2016

Silver nanoparticles are valuable in the field of plasmonics since silver has a higher field enhancement factor compared to other metals that possess plasmonic properties. The plasmonic properties of silver nanoparticles can be finely tuned to the incident light wavelength through their size, shape and dielectric environment, and they have long-term stability. In this work, an ultrathin polymer shell is deposited around the silver nanoparticles using the Layer-by-Layer method to provide additional stability. The effect of this polymer shell on the plasmonic properties is studied by building a finite element model (FEM) in COMSOL Multiphysics® software. The near-field enhancement factor of these silver-polymer core-shell nanoparticles is studied as a function of the polymer shell thickness to determine the optimal shell thickness required for a given application. These ultrastable silver-polymer core-shell nanoparticles are further used in plasmon enhanced semiconductor (TiO2) photocatalysis. Simulating the interaction between silver and TiO2 is crucial to understand the mechanisms of near-field enhancement and charge transfer in plasmonic photocatalysis.