Resonance Energy Transfer Mediated by Metal-Dielectric Composite Nanostructures

Nanostructure-mediated energy transfer has attracted considerable attention

as a template for photocatalysis and solar energy conversion, and the use

of noble metal nanoparticles that support localized surface plasmon

resonances (LSPRs) has been widely explored as a medium for realizing

this paradigm. On the other hand, composite nanoparticles (CNPs)

comprised of a large dielectric bead and smaller metal nanostructures have

been shown to achieve efficient energy transfer to small-molecule

adsorbates through the interplay between dielectric scattering resonances

and the broad-band absorption associated with the metal nanostructure.

This scattering mediated absorption can enable selective photochemistry

without relying on the plasmonic properties of noble metal nanoparticles.

While the precise photochemical mechanisms themselves remain unknown,

resonance energy transfer (RET) is one feasible route for initiating the

photochemistry. We demonstrate computationally that CNPs indeed

facilitate RET to small-molecule adsorbates and that CNPs offer a

framework in which one can design RET donors that outperform typical

plasmonic nanoparticles employed within LSPR-driven RET under comparable

illumination conditions. We also exploit the tunability of the resonances

on the CNPs to realize strong coupling between the CNP and LSPR modes.