One-dimensional J-aggregates: Dependence of the properties of the exciton band on the model of the intermolecular coupling Original Research Article

The spectral properties of one-dimensional thiacarbocyanine dye aggregates were simulated by the combination of exciton interaction with a diagonal energetic disorder. Contrary to previous models incorporating disorder, the exciton interaction was calculated using the transition densities obtained form PPP-wave functions and interactions between all molecules were considered. The effects of the aggregate size, non-nearest neighbor interactions, diagonal disorder and to some extent exciton phonon coupling on the spectral position of the maxima, the FWHM of the spectra and the superradiance are investigated for H- and J-aggregates at 298 and 20 K. At 298 K the experimental properties of H-aggregates and J-aggregates of 3,3′-disulfopropyl-5,5′-dichloro-carbocyanine with 1 molecule per unit cell are compared to the simulations.