Tianjin Key Laboratory of Composite and Functional Materials , Tianjin 300072 , P. R. China.
Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Sciences , Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering , Tianjin 300072 , P. R. China.
ACS Appl Mater Interfaces. 2018 Jul 5;10(26):22435-22444. doi: 10.1021/acsami.8b05885. Epub 2018 Jun 21.
Large-area uniform of single-crystal tungsten disulfide (WS) is important for advanced optoelectronics based on two-dimensional (2D) atomic crystals. However, difficulties in controlling the interrelated growth parameters restrict its development in devices. Herein, we present the synthesis of triangular monolayered WS flakes with good uniformity and single crystal by adjusting the introduction time of sulfur precursor and the distances between the sources and substrates to control the nucleation density. Investigation of the morphology and structure by transmission electron microscopy and Raman spectroscopy indicates that a series of triangular (side length of 233 μm) monolayered WS flakes shows high-quality structure and homogenous crystallinity. Field-effect transistors based on the fabricated triangular monolayered WS with single crystal demonstrate environmentally stable charge transport with a field-effect mobility of 50.5 cm/V s and current modulation I/ I of ∼10. The results of this study pave the way for the application of monolayered WS in a multitude of 2D-material-based devices.
大面积均匀的单晶二硫化钨（WS 2 ）对于基于二维（2D）原子晶体的先进光电子学非常重要。然而，控制相关生长参数的困难限制了其在器件中的发展。在此，我们通过调整硫前体的引入时间和源与基底之间的距离来控制成核密度，从而合成了具有良好均匀性和单晶的三角形单层 WS 薄片。通过透射电子显微镜和拉曼光谱对形貌和结构的研究表明，一系列三角形（边长为 233μm）单层 WS 薄片具有高质量的结构和均匀的各向同性结晶度。基于所制备的具有单晶的三角形单层 WS 制成的场效应晶体管表现出环境稳定的电荷输运特性，场效应迁移率为 50.5cm/V s ，电流调制比 I/ I 约为 10。这项研究的结果为单层 WS 在多种基于 2D 材料的器件中的应用铺平了道路。
