# Study of Electron-Vibrational Interaction in Molecular Aggregates Using Mean-Field Theory: From Exciton Absorption and Luminescence to Exciton-Polariton Dispersion in Nanofibers

## TL;DR

This paper presents a generalized mean-field model to analyze electron-vibrational effects on absorption, luminescence, and exciton-polariton dispersion in molecular aggregates and nanofibers, validated against experimental data.

## Contribution

The work extends previous mean-field electron-vibrational theory to include spatial symmetry, luminescence, and dispersion, linking monomer and aggregate behaviors.

## Key findings

- Calculated absorption and luminescence spectra of molecular aggregates.
- Modeled exciton-polariton dispersion in nanofibers.
- Validated theory with experimental propagation data in organic nanofibers.

## Abstract

We have developed a model in order to account for electron-vibrational effects on absorption, luminescence of molecular aggregates and exciton-polaritons in nanofibers. The model generalizes the mean-field electron-vibrational theory developed by us earlier to the systems with spatial symmetry, exciton luminescence and the exciton-polaritons with spatial dispersion. The correspondence between manifestation of electron-vibrational interaction in monomers, molecular aggregates and exciton-polariton dispersion in nanofibers is obtained by introducing the aggregate line-shape functions in terms of the monomer line-shape functions. With the same description of material parameters we have calculated both the absorption and luminescence of molecular aggregates and the exciton-polariton dispersion in nanofibers. We apply the theory to experiment on fraction of a millimeter propagation of Frenkel exciton polaritons in photoexcited organic nanofibers made of thiacyanine dye.