Design Principles for Directing Energy and Energetic Charge Flow in Multicomponent Plasmonic Nanostructures

The decay of localized surface plasmons supported by plasmonic metal nanoparticles results in the formation of energetic charge carriers within the nanoparticles. Once formed, these charge carriers can transfer to chemically attached materials where they can perform a function. The efficient extraction and utilization of these charge carriers in various applications hinges on the ability to design plasmonic nanostructures with highly localized charge carrier generation at specific locations in the nanostructure. Herein, we shed light on the physical mechanisms governing the flow of energy in resonantly excited multimetallic plasmonic nanoparticles. We demonstrate that coating plasmonic nanostructures with nonplasmonic metals can result in the preferential dissipation of energy (i.e., formation of charge carriers) in the nonplasmonic metal and that the extent of this dissipation depends heavily on the electronic structure of the constituent metals. We use experimental and modeling studies of various core–shell nanostructures to develop a transparent physical framework of energy transfer in these systems and discuss how this framework can be used to engineer nanostructures that allow for high efficiencies of charge carrier extraction.