Observation of the Graphene Surface Structure at the Early Stages of Graphene Growth on Copper

Abstract

Scalable growth is essential for graphene-based applications. Recent development has enabled the achievement of the scalability by use of chemical vapor deposition (CVD) at 1000°C with copper as a catalyst and methane as a precursor gas. Here we report our observation of early stage of graphene growth based on an ethylene-based CVD method, capable of reducing the growth temperature to 800°C for monolayer graphene growth on copper films and foils. We track the early stages of slow growth under low ethylene flow rate and observe the graphene domain evolution by varying the temperature and growth time. As the physical properties of the surface also changes along with the graphene domain structure, we also investigate the surface energy of the partially grown graphene. Thus, we demonstrate that the hydrophobicity can be fine tuned by controlling the initial growth of the graphene domains.