Electrical Characterization of a Switchable Molecular Wire via Mechanically Controllable Break Junctions

Molecular electronics has been a eld of big interest for the last years. Using the technique of mechanically controllable break junctions we characterize the Switchable Molecular Wire Oligo(phenylene ethynylene)-embedded Difurylperuorocyclopentenes (SMW) in liquid environment. Via light irradiation the SMW can be switched between two well-defined conductance states. Conductance and hysteresis measurements allow us to identify the two states providing the basis for a comprehensive study of the in situ switching process. Based on the analysis with the transport model assuming transport through a single molecular level, we confirm that a reliable contact of the molecules to the gold contacts is formed and extract the energy of the molecular levels and the coupling constants between molecule and electrodes.