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.