A Numerical Spectroscopic Investigation on the Functionality of Molecular Excitons in Tuning the Plasmonic Splitting Observed in Core/Shell Hybrid Nanostructures

作者：Guelen Demet

来源：Journal of Physical Chemistry C, 2010, 114(32): 13825-13831.

DOI：10.1021/jp101658b

Coupling between localized surface plasmon resonance (LSPR) of metal nanoparticles and molecular excitons in core/shell hybrid nanostructures attracts increasing attention. Emphasis has been on fine-tuning exciton-plasmon coupling by controlling the LSPR of metal nanoparticles, while functionality of the intact excitonic resonance in this fine-tuning has received less attention. Our assertion has been that as a localized polarized excitation, just like the LSPR, the excitonic resonance should also sense the effective dielectric medium provided by the metal core and embedding medium. We have thereby provided a series of numerical experiments to investigate effective medium effects on the absorption of the core/shell hybrid complexes. Excitonic resonance is shown to experience an effective dielectric medium induced band splitting. Despite existence of two excitonic resonances, plasmonic splitting is shown to be due to coupling between blue-shifted exciton and plasmon resonances. Further investigation of dependencies of excitonic band splitting and exciton-plasmon coupling on the shell thickness and excitonic oscillator strength yields important insight into the mechanism of exciton-plasmon coupling.

• 出版日期2010-8-19