Liquid phase deposition of supramolecular monolayers of zinc porphyrin molecules on graphite

Molecular monolayers of zinc porphyrins deposited from liquid sources on graphite substrates have been characterized using atomic force microscopy. The morphology of the molecular layers shows a strong dependence on both the structure of the individual molecules and the properties of the solvent used for the deposition. By controlling the concentration of the starting solution and the amount of liquid applied to the graphite surface, single layer high molecular weight films have been successfully grown with a variety of zinc porphyrin molecules. The nucleation and growth, similar to those commonly observed in vapour deposition, have been found to depend on the strength of the intermolecular interaction as well as the level of interaction between the solvent molecules and the substrate.