Microfaceting: A new logic for hot-carrier energy harvesting in hybrid plasmonic nanostructures

Summary

At the core of plasmonic-enhanced applications lies photon energy harvesting and conversion over plasmonic/non-plasmonic multicomponent hybrid materials. The direct excitation of local interfacial electronic states that arise from the chemical bonding between plasmonic metal and attached functional entity opens up an exceptionally efficient energy transfer channel. However, there is a lack of a general strategy to manipulate these states and insights into the impact of such electronic modulations on light-driven functionalities. We demonstrate in a plasmonic-metal/molecule hybrid system that by precisely manipulating microfacets of nanostructures, it is possible to engineer metal-adsorbate-hybridized interfacial states in terms of both energy gap opening and permissible electronic excitations. Low-index microfacets feature much more efficient interfacial electronic transitions than high-index ones, retarding plasmonic relaxation and entailing enhanced photocatalytic activity toward molecular coupling reactions. This study contributes to pushing forward frontiers of plasmonic research from geometric control to nanostructure engineering and enlightens new strategies for plasmonic-enhanced applications.