Absorption spectra simulation of amalgamation-type cyanine dye aggregates in LB films

Simulation of the absorption spectra of the 2D amalgamation-type molecular aggregates consisting of two kinds of cyanine dyes is being investigated. T hese aggregates are modeled by the brick-stone structure in the extended di pole approximation of Kuhn et al. The simulation takes into account the vec tor properties of the transition dipole moment, its orientation, diagonal d isorder and the composition of the aggregate. A good fit with the experimen t is obtained for the dipole tilt angle theta = 90 degrees - alpha = 30 deg rees, dipole moment mu = 10 D and the disorder parameter of 750 cm(-1) for various molar fractions of two dyes. (C) 2000 Elsevier Science B.V. All rig hts reserved.