Self-assembled aromatic oligoazomethines on polar surfaces

The reaction between aromatic dialdehydes and diamines is studied by differential scanning calorimetry-thermal gravimetric analysis (DSC-TGA) measurements. It can be shown that the condensation reaction starts at temperatures below 100 °C. Thus, the high rate and the high conversions of this reaction lead to a new technique of thin-film growth on polar substrates, by successive deposition of monomer layers under high vacuum. Gravimetric measurements show that the first step is a bonding between the organic molecules and the surface. This leads to an oriented prime layer of deposited monomers. In the following steps reactive partners are deposited successively on the surface, layer by layer. Thin films grown by this technique are studied by UV-Vis spectroscopy. These well-ordered films can be applied as interfaces between organic and inorganic layers in solid-state optoelectronic devices.