Contact Resistance Properties between Nanotubes and Various Metals from Quantum Mechanics

Abstract

We report on the interfacial structure, the current−voltage (I−V) characteristics, and contact resistance of metal electrode−carbon nanotube contacts for five metals, Ti, Pd, Pt, Cu, and Au, based on first-principles quantum mechanical density functional and matrix Green's function methods. We find that Ti leads to the lowest contact resistance followed by Pd, Pt, Cu, and Au. The sequence, Ti ≫ Pd > Pt > Cu > Au, correlates well with the predicted cohesive strength of the electrode−carbon interface. In addition Ti leads to linear I−V characteristics up to ∼1 V, suggesting an Ohmic contact for both metallic and semiconductor nanotubes. However, the high reactivity of the Ti electrode at the contact to the nanotube distorts the nanotube structure.

Group Members

William A. Goddard III

Charles and Mary Ferkel Professor