ABSORPTION LINESHAPE OF J-AGGREGATES OF THIACARBOCYANINE DYES - EXPERIMENT AND NUMERICAL STUDY

The experimental absorption spectra of J-aggregates of the carbocyanin e dyes THIATS and TDC were fitted to a segment and a continuous energy disorder (CED) model, From 6 K to room temperature the best fits were obtained using an exponential distribution of segment lengths. Both m odels gave equally good fits when the average length in the segment mo del corresponded to the average localization length in the CED model. At room temperature homogeneous broadening or/and an enhanced contribu tion of the off-diagonal disorder must be taken into account.