Numerical study of absorption spectra of Frenkel excitons in two-dimensional disordered lattices with long-range dipole–dipole interaction

Abstract

We consider two-dimensional arrays of two-level molecules whose excited states are described by Frenkel excitons. Local dipole moments are assumed to be perpendicular to the system plane so that intersite interaction depends only on the distance between far neighbors. We consider Gaussian randomness in the molecular positions and numerically determine the optical absorption line shape of finite random lattices with different degrees of disorder. Results are compared to those obtained within the framework of the nearest-neighbor approximation.