Suppression of photo-oxidation of organic chromophores by strong coupling to plasmonic nanoantennas

TL;DR

This study demonstrates that strong plasmon-exciton coupling in nanoscale systems can significantly suppress photo-oxidation of organic dyes, enhancing their stability and potentially improving optical device performance.

Contribution

It provides experimental evidence that strong coupling can control and suppress photobleaching in organic chromophores, a novel insight into photochemical stability in hybrid light-matter systems.

Findings

Photobleaching can be suppressed by tuning plasmon-exciton coupling.

Red-detuned nanoparticles achieve 100-fold stabilization of dyes.

Modified excited state dynamics influence photochemical reactivity.

Abstract

Intermixed light-matter quasiparticles - polaritons - possess unique optical properties owned to their compositional nature. These intriguing hybrid states have been extensively studied over the past decades in a wide range of realizations aiming at both basic science and emerging applications. However, recently it has been demonstrated that not only optical, but also material-related properties, such as chemical reactivity and charge transport, may be significantly altered in the strong coupling regime of light-matter interactions. Here, we show that a nanoscale system, comprised of a plasmonic nanoprism strongly coupled to excitons in J-aggregated form of organic chromophores, experiences modified excited state dynamics and therefore modified photo-chemical reactivity. Our experimental results reveal that photobleaching, one of the most fundamental photochemical reactions, can be effectively controlled and suppressed by the degree of plasmon-exciton coupling and detuning. In particular, we observe a 100-fold stabilization of organic dyes for the red-detuned nanoparticles. Our findings contribute to understanding of photochemical properties in the strong coupling regime and may find important implications for the performance and improved stability of optical devices incorporating organic dyes.