Electrical characterization of single biphenyl-propanethiol capped 4nm Au nanoparticles

The electrical properties of single biphenyl-propanethiol (BP3) capped Au nanoparticles with a diameter of approximately 4nm immobilized in between nanoelectrodes are characterized. The total conductivity across the gap formed by the nanoelectrodes is shown to be critically dependent upon how perfectly the NP fills the gap. For nanogaps partially and completely filled with a nanoparticle, respectively, representative measurements are shown. From transport measurements characteristic molecule parameters as the tunneling barrier height of the BP3 molecules and the remaining vacuum gap-width are obtained by a combination of Simmons fit and transition voltage spectroscopy.