Dong Jichen, Zhang Leining, Dai Xinyue, Ding Feng
Centre for Multidimensional Carbon Materials, Institute for Basic Science, Ulsan, 44919, Korea.
School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, Korea.
Nat Commun. 2020 Nov 17;11(1):5862. doi: 10.1038/s41467-020-19752-3.
Two dimensional (2D) materials consist of one to a few atomic layers, where the intra-layer atoms are chemically bonded and the atomic layers are weakly bonded. The high bonding anisotropicity in 2D materials make their growth on a substrate substantially different from the conventional thin film growth. Here, we proposed a general theoretical framework for the epitaxial growth of a 2D material on an arbitrary substrate. Our extensive density functional theory (DFT) calculations show that the propagating edge of a 2D material tends to align along a high symmetry direction of the substrate and, as a conclusion, the interplay between the symmetries of the 2D material and the substrate plays a critical role in the epitaxial growth of the 2D material. Based on our results, we have outlined that orientational uniformity of 2D material islands on a substrate can be realized only if the symmetry group of the substrate is a subgroup of that of the 2D material. Our predictions are in perfect agreement with most experimental observations on 2D materials' growth on various substrates known up to now. We believe that this general guideline will lead to the large-scale synthesis of wafer-scale single crystals of various 2D materials in the near future.
二维（2D）材料由一到几个原子层组成，其中层内原子通过化学键结合，而原子层之间则通过弱键结合。二维材料中高的键合各向异性使得它们在衬底上的生长与传统薄膜生长有很大不同。在此，我们提出了一个关于二维材料在任意衬底上外延生长的通用理论框架。我们广泛的密度泛函理论（DFT）计算表明，二维材料的生长边缘倾向于沿着衬底的高对称方向排列，因此，二维材料与衬底的对称性之间的相互作用在二维材料的外延生长中起着关键作用。基于我们的结果，我们概述了只有当衬底的对称群是二维材料对称群的子群时，才能实现二维材料岛在衬底上的取向均匀性。我们的预测与目前已知的关于二维材料在各种衬底上生长的大多数实验观察结果完全一致。我们相信，这一通用准则将在不久的将来促成各种二维材料的晶圆级单晶的大规模合成。
