Role of Hydrogen in Chemical Vapor Deposition Growth of Large Single-Crystal Graphene
Role of Hydrogen in Chemical Vapor Deposition Growth of Large Single-Crystal Graphene
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DOI：
10.1021/nn201978y
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发表时间：
2011-07-01
期刊：
影响因子：
17.1
通讯作者：
Smirnov, Sergei
中科院分区：
文献类型：
--
作者：
Vlassiouk, Ivan;Regmi, Murari;Smirnov, Sergei
我们表明，使用甲烷作为碳源的铜箔上的石墨烯化学气相沉积生长受到氢气的强烈影响，氢气似乎起着双重作用：单层生长所必需的表面结合碳的活化剂和控制石墨烯域的尺寸和形态的蚀刻试剂。对于固定的甲烷分压，所得到的生长速率在氢气分压为甲烷分压的200-400倍时具有最大值。石墨烯域的形态和尺寸以及层的数量随着氢压力从不规则形状的不完整双层变化到定义良好的完美单层六边形。拉曼光谱表明六边形中的锯齿形终止比扶手椅边缘更稳定。
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.