Giant static dipole moment in pseudoisocyanine J-aggregate with a hierarchical structure

A new model of hierarchical structure in J-aggregates, mesoaggregates and macroaggregates, is proposed on the basis of the linear and nonlinear optical properties of the oriented J-aggregates prepared by a novel vertical spin-coating method. The concentration dependence of dichroic spectra, wavelength dependence of hole-burning efficiency, and polarization dependence of electroabsorption are studied. The mesoaggregate is characterized by coherent exciton delocalized over the mesoscopic size, while the macroaggregate can be oriented by macroscopic centrifugal force of solvent flow. The macroaggregate is constituted by an incoherent ensemble of the mesoaggregates alternately stacked.