Molecular Electronics under Microscope

Electron transport through a single molecule is a central theme in molecular electronics. The ability to measure the conductance of a single molecule not only offers a new way to approach many interesting and fundamental problems in nanometer-scale science, but is also a necessary step towards the goal of building devices using single molecules. In order to measure single-molecule conductance, a molecular junction with a single molecule wired up to probe electrodes has to be fabricated. It is also essential to be able to efficiently and precisely control electron transport through such molecular junctions and understand the details of the factors that affect the transport before such devices can be made practical. SPM (STM & CAFM) based break junction (SPM-BJ) methods combing the imaging and measuring capabilities offer excellent capabilities to investigate single molecules transport properties through single molecule imaging and a complete control the junction by a series of modulation modes. This talk will focus on 1) introducing the SPM-BJ experimental platform for detailed junction modulation and control and 2) three exemplary research results obtained using the platform: molecule-electrode contacts issues, DNA structural effects on its conductance, and photo-electronic transport via exciton binding.