Hong Sungwook, Nomura Ken-Ichi, Krishnamoorthy Aravind, Rajak Pankaj, Sheng Chunyang, Kalia Rajiv K, Nakano Aiichiro, Vashishta Priya
Collaboratory for Advanced Computing and Simulations, Department of Physics & Astronomy, Department of Computer Science, Department of Chemical Engineering & Materials Science, and Department of Biological Sciences , University of Southern California , Los Angeles , California 90089-0242 , United States.
Argonne Leadership Computing Facility , Argonne National Laboratory , Argonne , Illinois 60439 , United States.
J Phys Chem Lett. 2019 Jun 6;10(11):2739-2744. doi: 10.1021/acs.jpclett.9b00425. Epub 2019 May 13.
Monolayer MoS is an outstanding candidate for a next-generation semiconducting material because of its exceptional physical, chemical, and mechanical properties. To make this promising layered material applicable to nanostructured electronic applications, synthesis of a highly crystalline MoS monolayer is vitally important. Among different types of synthesis methods, chemical vapor deposition (CVD) is the most practical way to synthesize few- or mono-layer MoS on the target substrate owing to its simplicity and scalability. However, synthesis of a highly crystalline MoS layer remains elusive. This is because of the number of grains and defects unavoidably generated during CVD synthesis. Here, we perform multimillion-atom reactive molecular dynamics (RMD) simulations to identify an origin of the grain growth, migration, and defect healing process on a CVD-grown MoS monolayer. RMD results reveal that grain boundaries could be successfully repaired by multiple heat treatments. Our work proposes a new way of controlling the grain growth and migration on a CVD-grown MoS monolayer.
单层二硫化钼因其优异的物理、化学和机械性能，是下一代半导体材料的杰出候选者。为了使这种有前景的层状材料适用于纳米结构电子应用，合成高度结晶的二硫化钼单层至关重要。在不同类型的合成方法中，化学气相沉积（CVD）由于其简单性和可扩展性，是在目标衬底上合成少层或单层二硫化钼最实用的方法。然而，合成高度结晶的二硫化钼层仍然难以实现。这是由于在化学气相沉积合成过程中不可避免地产生的晶粒和缺陷数量所致。在这里，我们进行了数百万原子的反应分子动力学（RMD）模拟，以确定化学气相沉积生长的二硫化钼单层上晶粒生长、迁移和缺陷愈合过程的起源。反应分子动力学结果表明，通过多次热处理可以成功修复晶界。我们的工作提出了一种控制化学气相沉积生长的二硫化钼单层上晶粒生长和迁移的新方法。
