One-step growth of graphene-carbon nanotube trees on 4″ substrate and characteristics of single individual tree

We develop a simple one-step growth method to obtain a novel kind of tree-like carbon nano composite structure on a 4″ stainless steel substrate, which is a nano graphene-carbon nanotube tree (GCT). The structures are synthesized by using a plasma enhanced chemical vapor deposition method. The GCT consists of few-layer graphenes (FLG) epitaxially growing from a carbon nanotube (CNT) and they can grow uniformly on a 4″ substrate. Analysis of chemical bonding between FLG and CNT is given. In addition, electron micrographs are presented to show how a tree grows. Finally, we also develop techniques to characterize both experimentally and theoretically the electrical conductivity, field electron emission, heat conduction and heat radiation of a GCT. The electrical conductivity of a GCT is compatible to high quality CNT, the current performance of field electron emission is significantly high compared to the other individual single nanostructure, and very outstanding heat radiation effect is found. We believe that this large-area GCTs film can find potential applications such as super capacitor, terahertz wave manipulation, heat dissipation and field electron emission.

shows the scanning electron microscope image of a graphene-carbon nanotube tree (GCT) film morphology. The interface between few layer graphene and carbon nanotube is connected by carbon-carbon chemical bonds, proving that few layer graphenes epitaxially grow from a carbon nanotube. In situ field electron emission characteristics of a single GCT shows its outstanding capability to emit large current.457