Monolayer MoS2 on sapphire: an azimuthal reflection high-energy electron diffraction perspective
Monolayer MoS2 on sapphire: an azimuthal reflection high-energy electron diffraction perspective
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蓝宝石上的单层 MoS2：方位角反射高能电子衍射视角
DOI：
10.1088/2053-1583/abce08
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发表时间：
2020-12
期刊：
影响因子：
5.5
通讯作者：
Wang Gwo-Ching
中科院分区：
文献类型：
--
作者：
Xiang Yu;Sun Xin;Valdman Lukas;Zhang Fu;Choudhury Tanushree H.;Chubarov Mikhail;Robinson Joshua A.;Redwing Joan M.;Terrones Mauricio;Ma Yuan;Gao Lei;Washington Morris A.;Lu Toh-Ming;Wang Gwo-Ching
c平面蓝宝石上的二硫化钼（MoS2）一直是二维材料界研究的热点。通过多种方法在蓝宝石上自下而上合成了具有优异电性能的单层MoS2，使其成为下一代纳米电子器件中非常有前途的候选材料。然而，与相对较小尺寸的去角质ML相比，具有相当质量的大面积ML MoS2仍然是一个相当大的挑战。为了克服这个瓶颈，全面了解生长的ML材料的结构是必不可少的第一步。本文采用方位角反射高能电子衍射（ARHEED）技术，对金属有机化学气相沉积在蓝宝石上生长的晶圆级连续外延ML - MoS2进行了详细的结构表征。利用ARHEED不仅可以对机器学习的二维空间结构进行统计映射，还可以对机器学习的三维空间结构进行统计映射。根据ARHEED强度曲线沿ML垂直方向的振荡，我们推导出ML与蓝宝石界面处的实际空间距离为~3 Å。三维互易空间图的定量衍射斑点展宽分析表明，ML - MoS2的取向域存在低密度缺陷和小角度错位。基于原子力显微镜高度分布分析、扫描透射电镜和密度泛函理论计算，我们认为在mos2ml和蓝宝石衬底之间存在钝化层。这种ARHEED方法也已应用于ML WS2，并有望适用于任意晶体或非晶体衬底上的其他ML过渡金属二硫化物。
Molybdenum disulfide (MoS2) on the c-plane sapphire has been a very popular system to study in the two-dimensional (2D) materials community. Bottom-up synthesis of monolayer (ML) MoS2 with excellent electrical properties has been achieved on sapphire by various methods, making it a very promising candidate to be used in the next generation nano-electronic devices. However, large-area ML MoS2 with comparable quality as the relatively small size exfoliated ML remains quite a challenge. To overcome this bottle neck, a comprehensive understanding of the structure of the as-grown ML material is an essential first step. Here, we report a detailed structural characterization of wafer-scale continuous epitaxial ML MoS2 grown by metalorganic chemical vapor deposition on sapphire using an azimuthal reflection high-energy electron diffraction (ARHEED) technique. With ARHEED we can map not only 2D but also 3D reciprocal space structure of the ML statistically. From the oscillation in the ARHEED intensity profile along the vertical direction of the ML, we derived a real space distance of ~3 Å at the interface of ML and sapphire. Quantitative diffraction spot broadening analyses of the 3D reciprocal space map reveals low density defects and a small angular misalignment of orientation domains in ML MoS2. Based on atomic force microscopy height distribution analysis, cross-section scanning transmission electron microscopy, and density functional theory calculations, we suggest that there exists a passivation layer between MoS2 ML and sapphire substrate. This ARHEED methodology also has been applied to ML WS2 and is expected to be applicable to other ML transition metal dichalcogenides on arbitrary crystalline or non-crystalline substrates.
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影响因子：
9.5
作者：
Zonghuan Lu;Xin Sun;Yu Xiang;Morris Washington;Gwo-Ching Wang;T. Lu
通讯作者：
Zonghuan Lu;Xin Sun;Yu Xiang;Morris Washington;Gwo-Ching Wang;T. Lu
影响因子：
3.2
作者：
D. Satapathy;B. Jenichen;K. Ploog;W. Braun
通讯作者：
D. Satapathy;B. Jenichen;K. Ploog;W. Braun
DOI：
--
发表时间：
2010
期刊：
Journal of Physics: Condensed Matter
影响因子：
--
作者：
J. Klimeš;D. Bowler;A. Michaelides
通讯作者：
J. Klimeš;D. Bowler;A. Michaelides
影响因子：
17.1
作者：
M. Rosenberger;Hsun-Jen Chuang;K. McCreary;Connie H Li;B. Jonker
通讯作者：
M. Rosenberger;Hsun-Jen Chuang;K. McCreary;Connie H Li;B. Jonker
影响因子：
1.9
作者：
G. Meyer;J. Wollschläger;M. Henzler
通讯作者：
G. Meyer;J. Wollschläger;M. Henzler