Li Honglai, Liu Hongjun, Zhou Linwei, Wu Xueping, Pan Yuhao, Ji Wei, Zheng Biyuan, Zhang Qinglin, Zhuang Xiujuan, Zhu Xiaoli, Wang Xiao, Duan Xiangfeng, Pan Anlian
Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, and College of Materials Science and Engineering , Hunan University , Changsha , Hunan 410082 , China.
School of Physics and Electronics , Hunan University , Changsha , Hunan 410082 , China.
ACS Nano. 2018 May 22;12(5):4853-4860. doi: 10.1021/acsnano.8b01646. Epub 2018 Apr 26.
Atomic substitution offers an important route to achieve compositionally engineered two-dimensional nanostructures and their heterostructures. Despite the recent research progress, the fundamental understanding of the reaction mechanism has still remained unclear. Here, we reveal the atomic substitution mechanism of two-dimensional atomic layered materials. We found that the atomic substitution process depends on the varying lattice constant (strain) in monolayer crystals, dominated by two strain-tuning (self-promoted and self-limited) mechanisms using density functional theory calculations. These mechanisms were experimentally confirmed by the controllable realization of a graded substitution ratio in the monolayers by controlling the substitution temperature and time and further theoretically verified by kinetic Monte Carlo simulations. The strain-tuning atomic substitution processes are of general importance to other two-dimensional layered materials, which offers an interesting route for tailoring electronic and optical properties of these materials.
原子取代为实现成分工程二维纳米结构及其异质结构提供了一条重要途径。尽管最近有研究进展，但对反应机理的基本理解仍不明确。在此，我们揭示了二维原子层材料的原子取代机制。我们发现原子取代过程取决于单层晶体中变化的晶格常数（应变），通过密度泛函理论计算由两种应变调节（自促进和自限制）机制主导。通过控制取代温度和时间在单层中可控地实现分级取代比，实验证实了这些机制，并通过动力学蒙特卡罗模拟进一步从理论上进行了验证。应变调节原子取代过程对其他二维层状材料具有普遍重要性，为定制这些材料的电子和光学性质提供了一条有趣的途径。
