Defects in Carbon Nanotubes and their Impact on the Electronic Transport Properties

Abstract

Synthesis of atomically pure carbon nanotubes (CNT) is difficult. Often, defects form in the structures consisting of carbon rings of non-uniform size and shape. Employing density functional theory combined with a Greens function scattering approach; we investigate the electronic properties of defective CNTs. We use the sculpturene method to form CNTs with a range of defect types, consisting of four-, five-, seven-, eight-, and ten-atom rings. We find that these defects have a non-trivial effect on the transport, often leading to decreased conductance, but also effecting the band-gap (Eg). We also plot the local density of states around the Fermi energy for a range of systems and generally find that higher levels of disorder cause a greater degree of localisation, which helps to explain the electronic properties.