The shape of the J-band of pseudoisocyanine

We show that, within the coherent exciton scattering (CES) approximation, both the measured exponential band-tail and the detailed shape of the J-band region of the absorption spectrum of pseudoisocyanine aggregates can be reproduced with high accuracy, using only a single free parameter. Our numerical studies confirm analytical results that the J-band width depends crucially on the monomer absorption strength in the energy region where the J-band peak occurs.