Controlling drop-casting deposition of 2D Pt-octaethyl porphyrin layers on graphite

• Pt-OEP molecules are deposited via drop-casting technique in air at RT on graphite.
• Different solvents, solution concentration and drop volumes have been used.
• Low-boiling temperature solvents induce a preferential 3D porphyrin growth.
• Anisole (high-boiling solvent) induces a preferential layer-by-layer growth.

A drop-casting technique designed for getting a high control over thin layers of small organic molecules is assessed for the deposition of Pt-octaethyl porphyrin on highly oriented pyrolytic graphite. We demonstrate that by a proper choice of solvent, namely anisole, it is possible to obtain an almost homogeneous 2D film at the micrometric scale in few minutes (evaporation time of the solvent). This growth strategy represents a reasonable alternative for Pt-octaethyl molecules deposition to longer and more expensive techniques in many applications and could be probably extended to other porphyrins and porphyrinic compounds.