Origin of ultrafast growth of monolayer WSe2 via chemical vapor deposition
Origin of ultrafast growth of monolayer WSe2 via chemical vapor deposition
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DOI：
10.1038/s41524-019-0167-2
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发表时间：
2019-02-27
影响因子：
9.7
通讯作者：
Zhang, Yong-Wei
中科院分区：
文献类型：
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作者：
Chen, Shuai;Gao, Junfeng;Zhang, Yong-Wei
最近已经通过化学气相沉积在金衬底上实现了具有紧凑三角形形态的大面积、高质量WSe 2畴的超快生长。然而，负责超快速增长的潜在机制仍然难以捉摸。在这里，我们首先分析生长过程，并确定两种可能的途径，可能实现超快增长：路径1，快速边缘附着和超快边缘扩散;路径2，快速扭结成核和超快扭结传播。我们进行动力学蒙特卡罗模拟和第一原理计算，以评估这两条路径的可行性，发现路径1是不可行的，由于高边缘扩散势垒计算的第一原理计算。值得注意的是，路径2再现了所有的实验生长特征（域形态，域取向和生长速率），并且相关的能量数据与第一原理计算一致。本工作揭示了WSe 2超快生长的基本机制，并可能为其他二维材料的超快生长提供新的途径。
The ultrafast growth of large-area, high-quality WSe2 domains with a compact triangular morphology has recently been achieved on a gold substrate via chemical vapor deposition. However, the underlying mechanism responsible for ultrafast growth remains elusive. Here, we first analyze growth processes and identify two possible pathways that might achieve ultrafast growth: Path 1, fast edge attachment and ultrafast edge diffusion; Path 2, fast kink nucleation and ultrafast kink propagation. We perform kinetic Monte Carlo simulations and first-principles calculations to assess the viability of these two paths, finding that Path 1 is not viable due to the high edge diffusion barrier calculated from first-principles calculations. Remarkably, Path 2 reproduces all the experimental growth features (domain morphology, domain orientation, and growth rate), and the associated energetic data are consistent with first-principles calculations. The present work unveils the underlying mechanism for the ultrafast growth of WSe2, and may provide a new route for the ultrafast growth of other two-dimensional materials.