Diverse axial chiral assemblies of J-aggregates in plexcitonic nanoparticles

Plexcitonic hybrids, consisting of metal nanoparticles and J-aggregates, are effective nanostructures to achieve a strong coupling regime. The chirality of the exciton in the strong coupled plexcitons provides more potential for the design of advanced optoelectronic devices. Here, we experimentally measured the circular dichroism (CD) spectra of plexcitonic hybrids, and researched the diverse chirality of J-aggregates assembled on the surface of the achiral Au nanorods. We found that the chirality of J-aggregates is not only related to the quantity of dye molecules in the plexcitonic, but also to the distribution in different positions of the nanorods, by analyzing the composition of the CD spectra with a quasistatic theory. The J-aggregates assembled on both ends and both sides of the nanorods had opposite chirality. The interaction between the longitudinal localized surface plasmon resonance (LLSPR) of the nanorods and J-aggregates achieved the strong coupling regime, and Rabi splitting of about 198.3 meV was observed. The research into the chirality of the plexcitons provided more detail on the chiral J-aggregates assembly on the nanoparticles, and give a perspective on the development of the strong coupling interactions and the design of optoelectronic systems.