Fabrication of thermally reduced graphene micro-tube and its electronic transport properties

Abstract

Graphene-based micro-tubes (μ-GTs) with good tubular structure were successfully fabricated from commercial graphene oxide dispersion by the electrospray deposition technique and thermal reduction. As a result of the structural changes, the electrical conductivity of the μ-GTs clearly increased as the annealing temperature increased. In particular, the μ-GTs with lower annealing temperatures exhibited distinct semiconductor properties. The electrical conduction mechanism can be explained by the 2-D variable-range hopping model. Furthermore, a transition from semiconductor to semi-metal was found to occur when the annealing temperature exceeded 900 °C, and the electrical conduction mechanism follows the exponential law of temperature in this condition.