The fluorescence characteristics and the topography of domains of J-aggregates formed by the thiacarbocyanine dye THIATS (3,3‘-disulfopropyl-5,5‘-dichloro-9-ethylthiacarbocyanine) adsorbed onto a dioctadecyldimethylammonium bromide (DODAB) layer and deposited on a solid substrate were studied using confocal fluorescence microscopy and atomic force microscopy (AFM). The fluorescence and topography of the films reveal a one-to-one correlation for the domains formed by the adsorbed cyanine dyes. The packing of the dye molecules in the bulk of the domains remains unchanged after deposition. The thickness of the dye layer, determined by atomic force microscopy, confirms that only a single dye layer, wherein the dye molecules have an edge-on orientation, is deposited in these domains. The influence of the deposition process (Langmuir−Blodgett or Langmuir−Schaefer) is mostly limited to the amphiphile regions between the two-dimensional dye crystals and to the rim of the two-dimensional dye crystals. For the film...