Effect of contact interface configuration on electronic transport in (C 20) 2-based molecular junctions
Using first-principles calculations, we study the electronic transport properties in Ausbnd (C20)2sbnd Au molecular junctions with different contact interface configurations: point contact and bond contact. We observe that the transmission through the bond contact is considerably higher than that of point contact. Furthermore, the I-V characteristics are rather different. For the bond contact, we get a metallic behavior followed by a varistor-type behavior. While as for the point contact, the current increases very slowly in a nonlinear way and is one order of magnitude smaller than that of bond contact. We attribute these obvious differences to the distinct contact configurations.