Dynamical disorder affected transient absorption spectra: the excess energy degradation model

We employ a time resolved pump probe approach to strongly excited molecular aggregates to study disordering processes. The theory, which takes into ac count the effect of dynamic disordering in one-dimensional molecular system s, explains the experimentally measured features of the difference absorpti on spectra for PIC Cl J-aggregates fairly well, Specifically, the 'blue-shi fted' spectral position and magnitude of the difference absorption spectra are shown as appeared due to 'hot' processes of off-diagonal disordering of an excited aggregate after the annihilation event. (C) 2001 Elsevier Scien ce B.V. All rights reserved.