Atomic ordering and phase separation in lateral heterostructures and multijunctions of ternary two-dimensional hexagonal materials
Atomic ordering and phase separation in lateral heterostructures and multijunctions of ternary two-dimensional hexagonal materials
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DOI：
10.1103/physrevmaterials.6.074001
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发表时间：
2022-06
影响因子：
3.4
通讯作者：
Zhihong Huang
中科院分区：
文献类型：
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作者：
Zhihong Huang
三元单层的二维六方材料的生长和微观结构特性的检查，包括两个单独的二维晶粒和平面内的异质结构，多结，或超晶格。该研究是通过开发一个三元相场晶体模型，将亚晶格有序和三个原子组件之间的耦合。结果表明，在这种类型的二维三元晶体的组成模式或调制的过渡，从相分离的几何挫折晶格原子有序，可以通过不同程度的能量偏好的异质相邻的同质元素的。通过数值计算和分析种间空间相关性以及合金混合或无序程度，定量地确定了生长和系统条件的影响因素艾德。这些发现被应用于模拟具有原子级尖锐异质界面的单层横向异质结构的生长，以及通过边缘外延的顺序过程，形成相应的超晶格或具有多个异质结的结构，其结果与最近的过渡金属二硫属化物的面内多异质结构的实验一致。还探讨了一种不同类型的合金基横向异质结构和多结，其将三元有序合金域与二元化合物的邻接块相结合，提供了更广泛的各种二维异质结构材料。
The growth and microstructural properties of ternary monolayers of two-dimensional hexagonal materials are examined, including both individual two-dimensional crystalline grains and in-plane heterostructures, multijunctions, or superlattices. The study is conducted through the development of a ternary phase field crystal model incorporating sublattice ordering and the coupling among the three atomic components. The results demonstrate that a transition of compositional pattern or modulation in this type of two-dimensional ternary crystals, from phase separation to geometrically frustrated lattice atomic ordering, can be controlled via the varying degree of energetic preference of heteroelemental neighboring over the homoelemental ones. Effects of growth and system conditions are quantitatively identified through numerical calculations and analyses of interspecies spatial correlations and the degree of alloy intermixing or disordering. These findings are applied to simulating the growth of monolayer lateral heterostructures with atomically sharp heterointerface, and via the sequential process of edge-epitaxy, the formation of the corresponding superlattices or structures with multiple heterojunctions, with outcomes consistent with recent experiments of in-plane multi-heterostructures of transition metal dichalcogenides. Also explored is a distinct type of alloy-based lateral heterostructures and multijunctions which integrate ternary ordered alloy domains with the adjoining blocks of binary compounds, providing a more extensive variety of two-dimensional heterostructural materials.