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Epitaxial growth of two-dimensional cyanine dye single crystals by adsorption at a pre-conditioned fatty acid monolayer

✍ Scribed by Franz-Josef Schmitt; Wolfgang Knoll


Publisher
Elsevier Science
Year
1990
Tongue
English
Weight
992 KB
Volume
165
Category
Article
ISSN
0009-2614

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✦ Synopsis


We have studied the adsorption of water-soluble cyanine dyes (pseudoisocyanine, PIC and "stains all", SA) to monomolecular layers of arachidic acid (AA) at the water-air interface in a Langmuir trough. Upon adsorption the dye molecules organize themselves and form two-dimensional J-aggregates that can easily be observed and characterized in the fluorescence microscope. We show that AA can be "conditioned" by the adsorption of PIC in a lateral order that can be read-out after desorption of this first dye, by the adsorption of another dye, SA in our case. We interpret this memory effect as being caused by a structural and/or orientational modification of the AA monolayer that controls in addition to an electrostatic contribution, details of the crystal morphology and in this sense is a first example of epitaxial growth of two-dimensional organic crystals.