Etching-Controlled Growth of Graphene by Chemical Vapor Deposition

Graphene growth and etching are reciprocal processes that can reach a dynamic balance during chemical vapor deposition (CVD). Most commonly, the growth of graphene is the dominate process, while the etching of graphene is a recessive process often neglected during CVD growth of graphene. We show here that through the rational design of low-pressure CVD of graphene in hydrogen-diluted methane and regulation of the flow rate of H₂, the etching effect during the growth process of graphene could be prominent and even shows macroscopic selectivity. On this basis, etching-controlled growth and synthesis of graphene with various morphologies from compact to dendritic even to fragmentary have been demonstrated. The morphology–selection mechanism is clarified through phase-field theory based on simulations. This study not only presents an intriguing case for the fundamental mechanism of CVD growth but also provides a facile method for the synthesis of high-quality graphene with trimmed morphologies.