Huang Chung-Che, Wang He, Cao Yameng, Weatherby Ed, Richheimer Filipe, Wood Sebastian, Jiang Shan, Wei Daqing, Dong Yongkang, Lu Xiaosong, Wang Pengfei, Polcar Tomas, Hewak Daniel W
Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, United Kingdom.
nCAT, University of Southampton, Southampton SO17 1BJ, United Kingdom.
ACS Appl Mater Interfaces. 2022 Sep 21;14(37):42365-42373. doi: 10.1021/acsami.2c12174. Epub 2022 Sep 8.
The fabrication process for the uniform large-scale MoS, WS transition-metal dichalcogenides (TMDCs) monolayers, and their heterostructures has been developed by van der Waals epitaxy (VdWE) through the reaction of MoCl or WCl precursors and the reactive gas HS to form MoS or WS monolayers, respectively. The heterostructures of MoS/WS or WS/MoS can be easily achieved by changing the precursor from WCl to MoCl once the WS monolayer has been fabricated or switching the precursor from MoCl to WCl after the MoS monolayer has been deposited on the substrate. These VdWE-grown MoS, WS monolayers, and their heterostructures have been successfully deposited on Si wafers with 300 nm SiO coating (300 nm SiO/Si), quartz glass, fused silica, and sapphire substrates using the protocol that we have developed. We have characterized these TMDCs materials with a range of tools/techniques including scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), micro-Raman analysis, photoluminescence (PL), atomic force microscopy (AFM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and selected-area electron diffraction (SAED). The band alignment and large-scale uniformity of MoS/WS heterostructures have also been evaluated with PL spectroscopy. This process and resulting large-scale MoS, WS monolayers, and their heterostructures have demonstrated promising solutions for the applications in next-generation nanoelectronics, nanophotonics, and quantum technology.
通过范德华外延（VdWE），利用MoCl或WCl前驱体与反应性气体H₂S反应，分别形成MoS₂或WS₂单层，从而开发出了均匀大规模的MoS₂、WS₂过渡金属二硫属化物（TMDCs）单层及其异质结构的制备工艺。一旦制备出WS₂单层，通过将前驱体从WCl改为MoCl，或者在MoS₂单层沉积在衬底上之后将前驱体从MoCl切换为WCl，就可以轻松实现MoS₂/WS₂或WS₂/MoS₂的异质结构。利用我们开发的方案，这些通过VdWE生长的MoS₂、WS₂单层及其异质结构已成功沉积在具有300 nm SiO₂涂层的硅片（300 nm SiO₂/Si）、石英玻璃、熔融石英和蓝宝石衬底上。我们使用了一系列工具/技术对这些TMDCs材料进行了表征，包括扫描电子显微镜（SEM）、X射线光电子能谱（XPS）、显微拉曼分析、光致发光（PL）、原子力显微镜（AFM）、透射电子显微镜（TEM）、能量色散X射线光谱（EDX）和选区电子衍射（SAED）。还通过PL光谱对MoS₂/WS₂异质结构的能带排列和大规模均匀性进行了评估。这一工艺以及由此得到的大规模MoS₂、WS₂单层及其异质结构，已为下一代纳米电子学、纳米光子学和量子技术的应用展示了有前景的解决方案。
