Phase field crystal modeling of grain boundary structures and growth in polycrystalline graphene
Phase field crystal modeling of grain boundary structures and growth in polycrystalline graphene
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DOI：
10.1016/j.jmps.2017.12.013
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发表时间：
2018-11-01
影响因子：
5.3
通讯作者：
Gao, Huajian
中科院分区：
文献类型：
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作者：
Li, Jiaoyan;Ni, Bo;Gao, Huajian
大规模石墨烯制备和应用中的一个关键挑战是控制通过化学气相沉积（CVD）生长的多晶石墨烯中的晶界（GB）。在这里，我们采用相场晶体（PFC）模型来预测CVD生长的石墨烯中的平衡结构以及GBs的动态形成。结果表明，由聚集的5个|7| 5|用传统的重合位置晶格（CSL）理论构造的7位错偶极子在能量上是不利的，应该用分散的5位错偶极子代替|在构建GB的原子结构进行理论和数值研究时，如PFC模型所预测的那样，存在7个位错。PFC模型还通过控制预图案化生长种子中的晶粒取向来展示二维（2D）材料中工程化GB的可能路线，并提出了一个简单的几何规则，该规则解释了石墨烯中弯曲晶界的主要存在。作为我们的方法的潜在应用的一个突出的例子，我们展示了如何生长无三结多晶石墨烯，具有增强的机械强度和挑战传统的Hall-Petch关系。(C)2018爱思唯尔有限公司版权所有。
A key challenge in large-scale graphene fabrication and application is controlling the grain boundaries (GBs) in polycrystalline graphene grown by chemical vapor deposition (CVD). Here, we adopt a phase field crystal (PFC) model to predict the equilibrium structures as well as dynamic formation of GBs in CVD-grown graphene. The results demonstrate that GBs consisting of clustered 5|7|5|7 dislocation dipoles, as constructed by the conventional coincidence site lattice (CSL) theory, are not energetically favorable, and should be replaced by dispersed 5|7 dislocations, as predicted from the PFC model, when constructing GBs' atomistic structures for theoretical and numerical investigations. The PFC modeling also demonstrates possible routes of engineering GBs in two-dimensional (2D) materials by controlling grain orientations in pre-patterned growing seeds and suggests a simple geometric rule that explains the predominant existence of curved grain boundaries in graphene. As a prominent example of potential applications of our method, we show how to grow triple-junction-free polycrystalline graphene that exhibits enhanced mechanical strength and defy the traditional Hall-Petch relation. (C) 2018 Elsevier Ltd. All rights reserved.