Electrostatic current switching and negative differential resistance behavior in a molecular device based on carbon nanotubes

Abstract

The electronic transport properties of an all-carbon mechanically controlled molecular device based on carbon nanotubes are studied using non-equilibrium Green's function in combination with density functional theory. A segment of (10,0) single-walled carbon nanutube (SWCNT) is placed concentrically outside a (5,0) SWCNT, namely, a (5,0)@(10,0) double-walled carbon nanotube (DWCNT). It is found that the position, orientation and length scaling of the (10,0) SWCNT have crucial effects on the electronic transport properties of the system. When the (10,0) SWCNT is mechanically pushed forward along the axial direction, alternation of on/off switching behavior under low bias and negative differential resistance behavior under high bias are observed. Significant changes in the electronic transport properties arise when rotating the (10,0) SWCNT around the common axis or adding carbon atom layers in the transport direction. Theoretical explanations are proposed for these phenomena.