Figure 6
From: High-speed roll-to-roll manufacturing of graphene using a concentric tube CVD reactor
Analysis of sequential stages of R2R graphene growth: reduction of Cu, graphene nucleation and graphene growth, as determined by the position of the foil along the CTCVD reactor. Translation of the Cu substrate was stopped to “freeze” the various stages along the length of the substrate while the system was cooled rapidly. a) Schematic of the CTCVD with axial positions highlighted relative to the beginning of the heated zone (the foil is translating left-to-right). b) Visible light microscopy (top) and SEM (bottom) images of a Cu substrate at various positions along the length of the CTCVD reactor (translated at 25 mm/min). Cu grain boundaries become visible as the oxide layer is reduced (x = 100 mm, left), followed by nucleation of graphene near the injection holes (x = 125 mm, middle), transitioning to near full graphene coverage prior to exiting the heated zone (x = 225 mm, right).
