Morphology of self-assembled merocyanine J-aggregates in films studied by scanning near-field optical microscope

• Published in: Chemical physics letters Vol. 378; no. 1; pp. 47 - 54
• Main Authors: Hamanaka, Y., Kawasaki, O., Yamauchi, T., Nakamura, A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 29.08.2003; Elsevier Science
• Subjects: Atomic and molecular clusters; Atomic and molecular physics; Exact sciences and technology; Physics; Spectroscopy and geometrical structure of clusters; Studies of special atoms, molecules and their ions; clusters; Sulfur nitrogen heterocycle; Self-assembly; Domain structure; Molecular clusters; Merocyanine; Photoluminescence; Rigid solvent; Near-field scanning optical microscopy; Absorption spectra; J-aggregates; Experimental study; Organic compounds
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/S0009-2614(03)01239-9

Morphology of 6-methyl merocyanine J-aggregates self-assembled in polyvinyl alcohol (PVA) films by a spin-coating method has been investigated by means of scanning near-field optical microscope and confocal laser scanning microscope. Photoluminescence image measurements show that J-aggregates form different domain structures with a grain-shape and a fiber-shape depending on the concentrations of merocyanine and arachidic acid in the PVA film. From the polarization-dependent measurements, we have found that the 6-methyl merocyanine molecules construct a hierarchical structure of J-aggregates in which a J-aggregate domain is composed of coherent aggregates with the same transition dipole orientation.