270045 VO Conducting molecules (2012S)

Within the last 2-3 decades research into the conductivity of single molecules adsorbed between two metal surfaces in so-called nano-gaps has become a very active field for a rapidly increasing international community of scientists. The description of such molecular nano-junctions requires a close collaboration of theoreticians specializing on quantum mechanics based electronic structure calculations and experimentalists employing methods from surface physics and electrochemistry. Potential applications arising from this field of basic research range from nano-electronics to bio-sensors in medicine. In molecular electronics for instance, the assumption is that a variation of functional groups in single organic molecules can be sufficient for a substantial change in the charge transport through a nano-gap, thereby enabling the design of a molecular transistor or diode.
In this lecture the topic is introduced in the context of latest developments in micro-electronics. The fundamental regimes for charge transport on the micro- and nano-scale are discussed. Experimental and theoretical techniques commonly used in the field are surveyed. Special emphasis is put on research examples of recent interest, where an interplay of theory and experiment has been vital for characterizing the conductivity of single molecules in nano-gaps.