Multilayered plexcitonic nanoparticles and methods of producing same for controlling plasmon-exciton distance

Abstract

Multilayered nanoparticles and methods of producing same are provided for controlling plasmon-exciton distance. The nanoparticles include a silver core, a polyelectrolyte spacer layer exterior to the silver core, and a J-aggregate cyanine dye outer shell. This multilayer architecture served as a framework for manipulating the dual coupling of localized surface plasmon resonance exhibited by the silver core with the molecular exciton exhibited by the J-aggregate outer shell. The polyelectrolyte spacer layer promotes the formation of an excitonic J-aggregate while serving as a means of controlling the plasmon-exciton coupling strength through changing the distance between the core and the shell. An analytical expression based on Mie Theory and the Transfer Matrix Method is provided for describing the optical response of these multilayered nanoparticles. Computational and experimental results illustrate that the absorption wavelength of the J-aggregate form of the dye is dependent on both the distance of the dye layer from the silver core and the degree of dye aggregation.