Conducting Properties of a Contact Between Open-End Carbon Nanotube and Various Electrodes

Abstract

The carbon nanotube (CNT) is becoming a promising candidate as electrical interconnects in nanoscale electronics. This paper reports the electronic structure and the electrical conducting properties at the interface between an open-end single wall CNT (SWCNT) and various metal electrodes, such as Al, Au, Cu, and Pd. A simulation cell consisting of an SWCNT with each end connected to the metal electrode was constructed. A voltage bias is prescribed between the left- and right-electrodes to compute the electronic conductance. Due to the electronic structure, the electron density and local density of states (LDOS) are calculated to reveal the interaction behavior at the interfaces. The first-principle quantum mechanical density functional and non-equilibrium Green’s function (NEGF) approaches are adopted to compute the transport coefficient. After that, the voltage-current relation is calculated using the Landauer-Buttiker formalism. The results show that electrons are conducted through the electrode/CNT/electrode two-probe system. The contact electronic resistance is calculated by averaging the values in the low voltage bias regime (0.0–0.1 V), in which the voltage–current relationship is found to be linear. And the electrical contact conductance of electrode/CNT/electrode system show the electrode-type dependent, however, the amplitude for different electrodes is of the same order.