Electrical Characterization of Single Organic Molecules via Mechanically Controllable Break Junctions

Molecular electronics has been of big interest for the last years. To allow an electrical characterization of single molecules a reliable contact to gold atoms is required. We ensure this by using single organic molecules with a plain structure, in particular 1,4-Diethoxy-2,5-bis (4-sulfanyl-phenylethynyl)-benzene and single stranded DNA fragments, dissolved in an organic non-polar solvent. For measurements we use the technique of mechanically controllable break junctions. IV-curves taken from single molecules connected to single gold atom contacts show the expected tunneling behavior, from which we gain the energy of the molecular level and the coupling between electrode and molecule.