J-AGGREGATES OF CYANINE DYE MOLECULES ADSORBED ON AGBR EMULSION CRYSTAL-SURFACES

The photosensitive dyes thiacarbocyanine and oxacarbocyanine on 0.7 mu m AgBr cubic crystals are observed by analytical-color-fluorescence e lectron microscopy (ACFEM), ultra-low-energy scanning electron microsc opy (SEM), and atomic force microscopy (AFM). ACFEM proves that the dy e makes J-aggregates, exhibiting cathodoluminescence spots about 30 x 70 nm. SEM reveals dye stripes epitaxially grown on the (001) AgBr sur face. AFM gives the thickness of the stripes, varying from 1 to 20 nm or more, and resolves single J-aggregate particles arranged in the str ipe. It is concluded that the dye forms in the stripes by island growt h rather than in monolayer adsorption.