Epitaxial nucleation of CVD bilayer graphene on copper
Epitaxial nucleation of CVD bilayer graphene on copper
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铜上 CVD 双层石墨烯的外延成核
DOI：
10.1039/c6nr04557j
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发表时间：
2016
期刊：
影响因子：
6.7
通讯作者：
Hongtao Wang
中科院分区：
文献类型：
--
作者：
Yenan Song;Jianing Zhuang;Meng Song;Shaoqian Yin;Yu Cheng;Xuewei Zhang;Miao Wang;Rong Xiang;Yang Xia;Shigeo Maruyama;Pei Zhao;Feng Ding;Hongtao Wang
双层石墨烯(BLG)已成为下一代电子应用的有前途的候选材料，特别是当它以伯纳尔堆叠的形式存在时，但其大规模生产仍然是一个挑战。本文介绍了以乙醇为前驱体在铜衬底上外延化学气相沉积(CVD)生长BLG的成核过程的实验和第一性原理计算研究。结果表明，适当调节乙醇的流量，可以在普通的铜片上得到均匀的BLG膜，其表面覆盖率接近90%，Bernal堆积率接近100%，第二层的外延成核主要是由于CH3自由基的活性，并存在单层石墨烯覆盖的铜表面。我们相信，这种成核机制将有助于阐明外延CVD过程中BLG的形成，并为可扩展合成结构和层数更可控的石墨烯提供许多新的策略。
Bilayer graphene (BLG) has emerged as a promising candidate for next-generation electronic applications, especially when it exists in the Bernal-stacked form, but its large-scale production remains a challenge. Here we present an experimental and first-principles calculation study of the epitaxial chemical vapor deposition (CVD) nucleation process for Bernal-stacked BLG growth on Cu using ethanol as a precursor. Results show that a carefully adjusted flow rate of ethanol can yield a uniform BLG film with a surface coverage of nearly 90% and a Bernal-stacking ratio of nearly 100% on ordinary flat Cu substrates, and its epitaxial nucleation of the second layer is mainly due to the active CH3 radicals with the presence of a monolayer-graphene-covered Cu surface. We believe that this nucleation mechanism will help clarify the formation of BLG by the epitaxial CVD process, and lead to many new strategies for scalable synthesis of graphene with more controllable structures and numbers of layers.