Growth of Adlayer Graphene on Cu Studied by Carbon Isotope Labeling
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- 作者：Qiongyu Li ; Harry Chou ; Jin-Hui Zhong ; Jun-Yang Liu ; Andrei Dolocan ; Junyan Zhang ; Yinghui Zhou ; Rodney S. Ruoff ; Shanshan Chen ; Weiwei Cai
- 刊名：Nano Letters
- 出版年：2013
- 出版时间：February 13, 2013
- 年：2013
- 卷：13
- 期：2
- 页码：486-490
- 全文大小：405K
- 年卷期：v.13,no.2(February 13, 2013)
- ISSN：1530-6992
文摘
The growth of bilayer and multilayer graphene on copper foils was studied by isotopic labeling of the methane precursor. Isotope-labeled graphene films were characterized by micro-Raman mapping and time-of-flight secondary ion mass spectrometry. Our investigation shows that during growth at high temperature, the adlayers formed simultaneously and beneath the top, continuous layer of graphene and the Cu substrate. Additionally, the adlayers share the same nucleation center and all adlayers nucleating in one place have the same edge termination. These results suggest that adlayer growth proceeds by catalytic decomposition of methane (or CHx, x < 4) trapped in a 鈥渘ano-chemical vapor deposition鈥?chamber between the first layer and the substrate. On the basis of these results, submillimeter bilayer graphene was synthesized by applying a much lower growth rate.