Synthesis and characterization of self-organized multilayered graphene–carbon nanotube hybrid films

Abstract

We report the synthesis and characterization of a self-organized graphene–carbon nanotube (CNT) hybrid film consisting of multilayer graphene (MLG) supported by vertical CNTs on a Si substrate. The hybrid film shows an interesting structure of graphene in connecting to vertical CNTs while maintaining ohmic contact at its junction. The in situ formation of a CNT–graphene heterojunction is confirmed by high resolution transmission electron microscopy (HRTEM). The as-obtained film shows a linear relationship for electrical conductance with significantly low resistance varying from 100–400 Ω on Si substrate. This hybrid film is inverted and transferred to flexible substrates for its application in flexible electronics, demonstrating an observable variation of electrical conductivity for both tension and compression. Furthermore, both turn-on field and total emission current were found to depend strongly on the bending radius of the film and were found to vary in ranges of 0.8–3.1 V μm⁻¹ and 4.2–0.4 mA, respectively.