Probing Electron Transport Mechanism in Single Molecule Junctions by Conductance and Thermoelectricity Measurements.

Understanding of the transport characteristics of the metal-molecule-metal junctions is a prerequisite for the development of functional molecule-based electronic devices. Submitted proposal focuses on the experimental studies of different aspects of the electron transport mechanism (tunneling, hopping and quantum interference effects) in a series of organic molecules that contain increasing number of repeating units connected by chemical bonds in series or in parallel. Conductance studies will be done as a function of molecular length and as a function of the number of conductance pathways using temperature resolved Scanning Tunneling Microscopy Break Junction technique. Furthermore, we aim at the development of the instrumentation for simultaneous measurements of the electric and thermoelectric currents, which would enable direct probing of the molecular energy level alignment with the electrode's Fermi level. Experimental results will be supplemented by theoretical computations of single molecule conductance and thermopower values using non-equilibrium Green´s functionformalism.