Catalyst-Free Direct Growth of Triangular Nano-Graphene on All Substrates

To epitaxially grow graphene, metallic catalysts or carbon containing silicon carbide have been typically utilized. The embedded metallic catalyst between graphene and the substrate as well as the expensive silicon carbide substrate create hurdles in the development of graphene-based devices. However, what is inevitably necessary is not a metallic catalyst but a flat plane able to hold the carbon species and to mediate their interaction on the plane. The plane needs neither to hold a large amount of carbon species nor be a highly efficient catalyst because one monolayer of carbon on the plane may be enough to grow graphene. In this study, graphene was grown directly on various substrates such as transparent substrates, insulators, and semiconductors without any catalyst. The directly grown graphene is triangular nano-graphene with sides of 100-200 nm in length. This study suggests that graphene can be directly grown on all substrates.