title: Equilibrium chemical vapor deposition growth of Bernal-stacked bilayer graphene.
abstract: Using ethanol as the carbon source, self-limiting growth of AB-stacked bilayer graphene (BLG) has been achieved on Cu via an equilibrium chemical vapor deposition (CVD) process. We found that during this alcohol catalytic CVD (ACCVD) a source-gas pressure range exists to break the self-limitation of monolayer graphene on Cu, and at a certain equilibrium state it prefers to form uniform BLG with a high surface coverage of ∼94% and AB-stacking ratio of nearly 100%. More importantly, once the BLG is completed, this growth shows a self-limiting manner, and an extended ethanol flow time does not result in additional layers. We investigate the mechanism of this equilibrium BLG growth using isotopically labeled (13)C-ethanol and selective surface aryl functionalization, and results reveal that during the equilibrium ACCVD process a continuous substitution of graphene flakes occurs to the as-formed graphene and the BLG growth follows a layer-by-layer epitaxy mechanism. These phenomena are significantly in contrast to those observed for previously reported BLG growth using methane as precursor.
authors.affiliation: Institute of Applied Mechanics, Zhejiang University , Zhejiang 310027, China.
authors.forename: Pei
authors.initials: P
authors.lastname: Zhao
authors.forename: Sungjin
authors.initials: S
authors.lastname: Kim
authors.forename: Xiao
authors.initials: X
authors.lastname: Chen
authors.forename: Erik
authors.initials: E
authors.lastname: Einarsson
authors.forename: Miao
authors.initials: M
authors.lastname: Wang
authors.forename: Yenan
authors.initials: Y
authors.lastname: Song
authors.forename: Hongtao
authors.initials: H
authors.lastname: Wang
authors.forename: Shohei
authors.initials: S
authors.lastname: Chiashi
authors.forename: Rong
authors.initials: R
authors.lastname: Xiang
authors.forename: Shigeo
authors.initials: S
authors.lastname: Maruyama
keywords: bilayer graphene; chemical vapor deposition; equilibrium; isotope labeling; layer-by-layer epitaxy