Alloy engineering is of great importance in expanding the two-dimensional (2D) material family and modulating the bandgap of atomically thin 2D transition metal dichalcogenides (TMDs). Here, we report the synthesis of large area and high quality 2H Mo_1-xRe_xS₂ (x<=0.02) monolayer crystals by NaCl-assisted and space-confined chemical vapor deposition strategy. The combined effects of both common salt and confined space help promote the growth of Mo_1-xRe_xS₂ alloy monolayer crystals. The as-grown Mo_1-xRe_xS₂ alloy monolayers are uniformly distributed on the whole growth substrates with a domain size of up to 90 μm. Optical images, X-ray spectroscopy, Raman and photoluminescence spectroscopy measurements and corresponding mapping figures reflect the high quality and uniformity of the monolayers. The Mo_1-xRe_xS₂ alloy based phototransistor device exhibit good photoresponse to visible light with a response time of less than 0.2 s. Such alloy engineering of atomically thin 2D TMDs is useful for their future applications in optoelectronics.

合金工程在扩展二维（2D）材料族和调节原子上薄的2D过渡金属二卤化金属（TMD）的带隙方面非常重要。在这里，我们报告了NaCl辅助和空间受限的化学气相沉积策略合成的大面积和高质量2H Mo _1-x Re _x S ₂（x <= 0.02）单层晶体。食盐和有限空间的共同作用有助于促进Mo _1-x Re _x S ₂合金单层晶体的生长。Mo _1-x Re _x S ₂合金单层均匀分布在整个生长衬底上，其畴尺寸最大为90μm。光学图像，X射线光谱，拉曼光谱和光致发光光谱测量以及相应的映射图反映了单层的高质量和均匀性。基于Mo _1-x Re _x S ₂合金的光电晶体管器件对可见光表现出良好的光响应，响应时间小于0.2 s。这种原子薄的2D TMD的合金工程对于它们在光电子学中的未来应用很有用。