Nature of exciton-exciton annihilation in an aggregated cyanine dye

For aggregated 1,1',3,3'-tetraethyl-5,5',6,6'-tetrachlorobenzimidazolocarbocyanine (TTBC) adsorbed onto silica, we have ascertained that coherent optical dynamical processes play key roles in defining the temporal response and spectral profile of the fluorescence. We have also determined which coherent processes are involved in what might generally be termed exciton-exciton annihilation. Additionally, we provide in the TTBC system a concrete example of room temperature superradiance.