Photophysical Behaviors of J-Aggregates of Merocyanine in Langmuir-Blodgett Films

Abstract
J-Aggregates of a long-chain merocyanine can be formed in the mixed monolayers with glycerol derivatives, phospholipids and cholesterol. Its morphologies observed by a fluorescence microscopy are dependent on the matrix agents and the compositions. The photoactive J-aggregates in LB films were characterized by the weak exciton-phonon coupling and the fluorescence occured by a radiative annihilation from the free exciton state. From measurements of the fluorescence decay curves for a single layer of the J-aggregates, the lifetine has been found to be 5–11 ps irrespective of the matrix agents. In the LB systems containing the J-aggregate as a donor combined with long-chain bipyridinium as an acceptor at a distance of 20.2–30.2 A, it has been found that the fluorescence decays more rapidly.