Role of Hydrogen in Chemical Vapor Deposition Growth of Large Single-Crystal Graphene

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• 作者：Ivan Vlassiouk ; Murari Regmi ; Pasquale Fulvio ; Sheng Dai ; Panos Datskos ; Gyula Eres ; Sergei Smirnov
• 刊名：ACS Nano
• 出版年：2011
• 出版时间：July 26, 2011
• 年：2011
• 卷：5
• 期：7
• 页码：6069-6076
• 全文大小：1016K
• 年卷期：0
• ISSN：1936-086X

文摘

We show that graphene chemical vapor deposition growth on copper foil using methane as a carbon source is strongly affected by hydrogen, which appears to serve a dual role: an activator of the surface bound carbon that is necessary for monolayer growth and an etching reagent that controls the size and morphology of the graphene domains. The resulting growth rate for a fixed methane partial pressure has a maximum at hydrogen partial pressures 200–400 times that of methane. The morphology and size of the graphene domains, as well as the number of layers, change with hydrogen pressure from irregularly shaped incomplete bilayers to well-defined perfect single layer hexagons. Raman spectra suggest the zigzag termination in the hexagons as more stable than the armchair edges.