Formation of highly transmissive liquid metal contacts to carbon nanotubes

Abstract

We have developed a method to produce liquid metal contacts to carbon nanotubes that allows direct measurement of the influence of the contact on the nanotube conductance. Gallium is deposited onto standard gold nanotube contacts, where it gradually spreads to coat the contact region. The two-terminal multiwall nanotube conductance increases by as much as 1.2e2∕h during the transition from gold to gallium contacts, and approaches 2e2∕h at room temperature, with a current density of 2×108A∕cm2. Surprisingly, the conductance is independent of the contact area or contact separation, providing evidence that transport is ballistic in multiwall nanotubes.