Two-dimensional materials, including transition-metal dichalcogenides (TMDs), have aroused wide interest due to their various applications in gas sensors and photoelectric devices. However, achieving a uniform distribution of materials on the substrate is still a challenging and urgent problem. In this article, the factors influencing the material distribution during the chemical vapor deposition process are investigated by a simulation method, and the results show that the unequal velocity distributions caused by the carrier gas flow on the growing surface play an important role in influencing the crystal distribution. Boundary layer theory is used to explain the mechanism of the effect of the carrier gas flow on the growth uniformity. An improved method is proposed to improve the material uniformity by changing the placement of the Si/SiO₂ substrate from face down to face up. The simulation and experimental results show that uniformly distributed MoS₂ with a large size and good quality can be obtained with the improved method. This work provides a method for preparing uniformly distributed TMDs on a substrate, which should facilitate subsequent research of two-dimensional materials and promote the application of two-dimensional materials.

中文翻译：

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借助有限元法促进基于CVD法的晶体分布均匀性

二维材料，包括过渡金属二硫化氢（TMD），由于其在气体传感器和光电设备中的各种应用而引起了广泛的关注。然而，实现材料在基板上的均匀分布仍然是一个挑战和紧迫的问题。本文通过模拟方法研究了影响化学气相沉积过程中材料分布的因素，结果表明，载气流在生长表面上引起的不均匀速度分布在影响晶体生长中起着重要作用。分配。边界层理论用于解释载气流对生长均匀性的影响机理。提出了一种通过改变Si / SiO的位置来提高材料均匀性的改进方法₂基材从下到上。仿真和实验结果表明，改进后的方法可以得到大尺寸，高质量的均匀分布的MoS ₂。这项工作提供了一种在基板上制备均匀分布的TMD的方法，该方法应有助于二维材料的后续研究并促进二维材料的应用。