Optical properties of bimetallic compositional heterodimers

Abstract

Many important applications of nanometer-sized metal objects arise from the light-induced interactions between their component structures. Here, we demonstrate through state-of-the-art quantum mechanical simulations, the optical response of bimetallic heterodimers (two closely adjacent nanoparticles) composed of Al and Na nanoparticles. We calculate the optical response using time-dependent density functional theory. We found that Al–Na bimetallic heterodimers show rich optical features, strongly depending on the size heterogeneity and interparticle gap distances. In particular, we observe remarkable optical field enhancements and creation of new low-energy absorption peaks with respect to the single Al and Na nanoparticles. We believe that our results may influence the design of future nanoparticle-based optical nanoantenna.