Towards an understanding of the localized surface plasmon resonance decay pathways in bimetallic core-shell nanoparticles

Exploring the energy transfer mechanisms and understanding the localized surface plasmon resonance (LSPR) decay pathways of plasmas are of great importance for realizing effective composition adjustment and optimization of these novel solar energy materials. In this work, the absorption, scattering, and extinction decay channels of bimetallic core-shell nanostructures were calculated using the finite difference time domain method. Moreover, we separated the energy absorbed in the core and shell of the bimetallic nanoparticles to get a better understanding of the decay pathways of LSPR excited energy. Results indicated that the availability of fast inter band electron transitions in shell metals is the way to preferentially dissipate the surface electric field energy of nanoparticles. It was supported in essence that the larger imaginary part of the permittivity value of the metal shell is crucial for accelerating the decay channel via the surface of the nanoparticle. This work provided a basic physical framework and transparent design principles for material selection of multifunctional LSPR nano particles in practical applications.