A Rigorous Exploration of the Plexcitonic Phenomena: Hybridized Light-Matter States using Gold Nanoparticles and J-aggregates

Abstract

This work is focused on investigating the interplay between plasmon-exciton interactions within strongly coupled plexcitonic systems. Here, gold nanoparticles were used as the plasmonic component and molecular chains known as J-aggregates formed the excitonic component. To begin with, different spectroscopic techniques were used to characterize the photophysical properties of the excitonic systems including estimation of the exciton delocalization length in J-aggregates. This analysis was applied to various organic dyes that show the formation of J-aggregates upon increase of ionic strength and pH respectively. Later, we used carefully chosen interparticle interactions to establish the formation of two different plexcitonic systems using both the dyes. This demonstrates our control over the designs principles to reliably establish strongly coupled systems using different plasmonic and excitonic components. Subsequently, thorough characterizations were conducted to analyze the photophysical properties and evaluate the strength of coupling between the plasmonic and excitonic components. The results of this study draw the first steps into the application of strongly coupled plexcitonic systems for sensing and photocathalytic applications.