Plamonic Behavior of Metallic and Core-shell Nanostructures

Nanoscale interaction between the metal and semiconductor in core shell nanoparticles (NPs) when light is incident to this nanostructure, causes exhibiting reinforcedoptical responses and enhanced optical tunability in core shell NPs. In this work, we investigate the geometry and electronicproperties dependent optical properties of Au-SiO2 core shellNPs and Au NPs using boundary element method (BEM) by solving full Maxwell’s equation. We find out that severalimportant geometrical parameters such as shell thickness, core diameter, electronic properties of shell and surroundingenvironment affect the plasmon resonance wavelength, light scattering, absorption and extinction cross section of core shell NPs. We also investigate the effect of variation in size and surrounding refractive index on Au NPs. Surrounding refractive index dependence of Au NPs makes them suitable for plasmonic based sensors. We validate our BEM approach for spherical NPs with Mie theory