Dr Li Yang
Driven by the ultimate goal of molecular electronics, measurement of the electrical properties of single molecules sandwiched between asymmetric contacts has recently become an experimental reality. Here we report a novel scanning-tunneling-microscopy (STM) methods, named I(s) method for achieving this feat. In our methods, a graphene substrate is coated with a low-coverage monolayer of molecules bearing two terminal anchoring groups. A gold STM tip is employed, and in the course of the experiments, one (or a few) molecule(s) forms a junction between tip and substrate. The tip is brought close to the surface (without making contact), then withdrawn while the junction conductance is measured. Using this method we have made several landmark findings in this high-profile area. Some of the key issues affecting single molecule conductance will be discussed during the talk.