There is Room in the Middle: Unidirectional Energy Transfer in Plasmonic Nanohybrids through Intermediate Coherence
Year: 2026
Type: preprint
Abstract: Plasmon-induced resonance energy transfer (PIRET) is less well-known than hot carrier and polaritonic photocatalysis. The small dipole moment of individual excitons means donors and acceptors are weakly coupled in molecular energy transfer, so it is considered not efficient as hot carrier photocatalysis. And unlike the detailed quantum descriptions for polaritons in vibrational and electronic strong coupling, there is not a clear mechanistic model for PIRET. Here, we establish the underlying mechanism of PIRET and show energy transfer efficiencies of up to 75%. Gold nanorod (AuNR)-methylene blue polymer nanohybrids with identical plasmon resonance energies but with systematically varied core sizes enable direct comparison of the competing roles of oscillator strength and dephasing. Operando single-particle spectroelectrochemistry is used to quantify PIRET efficiencies. Open-quantum and classical electrodynamics simulations reveal that smaller AuNRs have an advantage because they combine stronger eigenmode-normalized local coupling with slower plasmon dephasing. PIRET efficiency increases from 30% to 75% with optimized AuNR sizes. The unique oscillator properties of AuNRs establish intermediate coherence, between more familiar weakly and strongly coupled regimes, as an effective route to unidirectional plasmon-to-exciton transfer. Intermediate coherence is a kinetic gate for PIRET, creating an efficient way to transform light into chemical degrees of freedom through which further photocatalysis is possible.
Source: ChemRxiv
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Award: G8676051196
OpenAlex ID: W7213536995