Influence of crystallinity on the electrical conductivity of individual carbon nanotubes

Abstract

The material properties of graphene and carbon nanotubes are highly sensitive to defects. Future exploitation of these materials will thereby rely on both a detailed understanding and classification schemes for material quality. Here we have used electron diffraction to measure the mean effective crystallite size of individual multiwalled carbon nanotubes, while also probing their electrical resistance. At room temperature we find a drastic shift in linear resistance of two orders of magnitude at a critical grain size of about 11 nm, which we interpret as an effect from quantum confinement and edge effects in the individual crystallites. For the regions above and below the critical grain size value we suggest a scaling model for the electrical conductivity within a single layer of a multiwalled carbon nanotube which connects its electrical conductivity with the effective crystallite size and tube diameter.

Keywords

• Carbon nanotubes
• Electrical conductivity
• Crystallinity
• Quantum confinement
• Transmission electron microscopy