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Supramolecular complex coupled to a metal nanoparticle: computational studies on the optical absorption
Yaroslav Zelinskyy1, Yuan Zhang, Volkhard May
1Institut für Physik, Humboldt-Universitäat zu Berlin, Newtonstraße 15, D-12489 Berlin, Germany.
The Journal of Physical Chemistry. A
|June 28, 2012
Summary
The interaction between supramolecular complexes and metal nanoparticles alters their light absorption spectra. This study quantifies spectral shifts and broadening due to Coulomb interactions, impacting exciton behavior.
Area of Science:
- Physical Chemistry
- Materials Science
- Spectroscopy
Background:
- Supramolecular complexes (SC) exhibit unique optical properties influenced by their environment.
- Metal nanoparticles (MNP) strongly interact with light and can modify the optical properties of nearby molecules.
Purpose of the Study:
- To compute and analyze the absorption spectra of a supramolecular complex (SC) near a spherical metal nanoparticle (MNP).
- To investigate the impact of Coulomb interactions and energy exchange coupling on SC exciton levels and oscillator strengths.
Main Methods:
- Utilized density matrix propagation based on a microscopic model.
- Incorporated Coulomb interaction between the SC and MNP, focusing on energy exchange coupling.
- Performed nonperturbative consideration of the interaction.
Main Results:
- Observed significant shifts and broadening of Frenkel-exciton levels in the SC due to MNP proximity.
- Quantified changes in oscillator strength of the exciton levels.
- Demonstrated that for J-aggregate type SCs, all exciton levels contribute to absorption near MNPs, unlike isolated SCs.
Conclusions:
- The proximity of MNPs profoundly alters the optical absorption spectra of SCs.
- Coulomb interactions and energy exchange coupling are key mechanisms driving these spectral modifications.
- Understanding these interactions is crucial for designing advanced optical materials and devices.
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