Materials Science and Engineering Program, Department of Mechanical Engineering, University of California Riverside, Riverside, CA, 92521, USA.
Department of Chemical Engineering & Materials Science, University of Minnesota, Minneapolis, MN, 55455, USA.
Sci Rep. 2017 Jul 25;7(1):6419. doi: 10.1038/s41598-017-06699-7.
It is of paramount importance to improve the control over large area growth of high quality molybdenum disulfide (MoS) and other types of 2D dichalcogenides. Such atomically thin materials have great potential for use in electronics, and are thought to make possible the first real applications of spintronics. Here in, a facile and reproducible method of producing wafer scale atomically thin MoS layers has been developed using the incorporation of a chelating agent in a common organic solvent, dimethyl sulfoxide (DMSO). Previously, solution processing of a MoS precursor, ammonium tetrathiomolybdate ((NH)MoS), and subsequent thermolysis was used to produce large area MoS layers. Our work here shows that the use of ethylenediaminetetraacetic acid (EDTA) in DMSO exerts superior control over wafer coverage and film thickness, and the results demonstrate that the chelating action and dispersing effect of EDTA is critical in growing uniform films. Raman spectroscopy, photoluminescence (PL), x-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM) and high-resolution scanning transmission electron microscopy (HR-STEM) indicate the formation of homogenous few layer MoS films at the wafer scale, resulting from the novel chelant-in-solution method.
提高大面积生长高质量二硫化钼（MoS）和其他类型二维二硫化物的控制水平至关重要。这种原子级薄的材料在电子学方面有很大的应用潜力，有望实现自旋电子学的首次真正应用。在此，我们开发了一种使用螯合剂在常见有机溶剂二甲基亚砜（DMSO）中进行掺入的方法，从而可以简便且可重复地生产晶圆级原子级薄的 MoS 层。以前，使用钼前体，四硫代钼酸铵（(NH)MoS）的溶液处理，并随后进行热解，以生产大面积 MoS 层。我们的工作表明，在 DMSO 中使用乙二胺四乙酸（EDTA）可以更好地控制晶圆覆盖率和薄膜厚度，并且结果表明 EDTA 的螯合作用和分散作用对于生长均匀的薄膜至关重要。拉曼光谱，光致发光（PL），X 射线光电子能谱（XPS），傅里叶变换红外光谱（FTIR），原子力显微镜（AFM）和高分辨率扫描透射电子显微镜（HR-STEM）表明，从新型螯合试剂在溶液中的方法中形成了均匀的少层 MoS 薄膜。
