The large-scale synthesis of two-dimensional transition metal dichalcogenides has been actively investigated in recent years. Here, we introduce a nonconventional synthesis process of 2-in.-scale monolayer MoS₂ with fairly good uniform coverage, which is based on a unique reaction mechanism due to the self-limiting precursor source in a proximity reaction environment with a distance of only ∼0.5 mm from the reaction zone. The large-scale MoS₂ monolayer film was successfully synthesized using an atmospheric pressure chemical vapor deposition reaction of precursor Mo film in flowing H₂S gas through an indirect sulfurization sequence with the oxidized Mo species. The short distance of ∼0.5 mm provides a unique advantage of uniformity with the self-limiting reaction due to the limited MoO_3-x supply. The chemical states of the precursor and deposited films at reaction temperatures were investigated to determine the reaction mechanism of the synthesis. This processing technique is extendable to other two-dimensional materials demanding large-scale coverage with good uniformity.

中文翻译：

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通过Mo膜的邻近蒸发大规模自限合成单层MoS ₂

近年来，已经积极地研究了二维过渡金属二硫化二氢的大规模合成。在这里，我们介绍一种具有相当好的均匀覆盖率的2英寸单层MoS ₂的非常规合成方法，该方法基于独特的反应机理，这是由于自限前体源在距离仅为1.9的邻近反应环境中距反应区约0.5 mm。利用前驱体Mo膜在流动的H _2中的大气压化学气相沉积反应成功合成了大规模的MoS ₂单层膜S气体通过与氧化的Mo物种的间接硫化序列。约0.5 mm的短距离由于MoO _{3- x的}供应有限而具有自限反应均匀性的独特优势。研究了前体和沉积膜在反应温度下的化学状态，以确定合成的反应机理。该处理技术可扩展到要求具有良好均匀性的大规模覆盖的其他二维材料。