Doping Concentration Tuning and Plasmonic Optical Properties Modelling of Metal Nano Particles Utilizing FDTD Method

Abstract

Among noble metal nanoparticles (MNPs), plasmonic effect of gold and silver nanoparticles (Au NPs and Ag NPs) is interesting to study due to their high near-field energy. This makes them excellent particles to absorb and scatter incident radiation in optical applications such as coupling them to fluorescent emitters to enhance their radiative decay and emission rate. This paper reviews and studies the methodology required for tuning the doping concentration and modelling plasmonic optical properties of Au NPs and Ag NPs by using finite difference time domain (FDTD) method. The frequency-dependent optical behaviour of MNPs is discussed. Plasmonic optical properties of MNPs can be characterised by their dimension, shape and doping concentration. Dimension and shape of MNPs can be simply defined in FDTD space grid (known as Yee grid). However, tuning MNPs doping concentration is more challenging which is undertaken by changing the spacing between MNPs and lateral boundaries of FDTD Yee grid. This can be vastly useful in Au NPs and Ag NPs optical optimization and applications to estimate plasmonic resonance based on doping concentration of particles.