The Essential Role of Cu Vapor for the Self-Limit Graphene via the Cu Catalytic CVD Method

Abstract

Because of the inconsistent observations, the Cu catalytic decomposition of methane for graphene synthesis is reexamined, i.e., via the surface absorption, decomposition to atomic carbon, and segregation. Here, we experimentally show the quantity of ambient Cu vapor is the key factor in graphene synthesis, which influences the dropwise condensations for airborne Cu clusters during growth. The massive carburization in Cu clusters and the calculation of carbon solubility in nanosized clusters are performed, experimented, and further examined from the growth of diamond-like-carbon films and ball-like diamonds via Cu vapor assisted growth on SiO₂. The affinitive interactions between Cu vapor, ambient gases, and solid surface are embodied. By combining the molecular dynamics for the redeposited Cu clusters to surface, the vehicle theory of Cu clusters, which transports the atomic carbon to the surface and completes the graphene growth, is thus proposed as the essential puzzle we considered