Li Chao, Kameyama Tomoya, Takahashi Tomoyuki, Kaneko Toshiro, Kato Toshiaki
Department of Electronic Engineering, Tohoku University, 980-8579, Sendai, Japan.
JST-PRESTO, Tohoku University, 980-8579, Sendai, Japan.
Sci Rep. 2019 Sep 10;9(1):12958. doi: 10.1038/s41598-019-49113-0.
Transition metal dichalcogenides (TMDs) attract intence attention due to its unique optoelectrical features. Recent progress in production stage of TMD enables us to synthesis uniform and large area TMD with mono layer thickness. Elucidation of growth mechanism is a challenge to improve the crystallinity of TMD, which is regargeded as a next crutial subject in the production stage. Here we report novel diffusion and nucleation dynamics during tungsten disulphide (WS) growth. The diffusion length (L) of the precursors have been measured with unique nucleation control methods. It was revealed that the L reaches up to ~750 μm. This ultra-long diffusion can be attributed to precursor droplets observed during in-situ monitoring of WS growth. The integrated synthesis of >35,000 single crystals and monolayer WS was achieved at the wafer scale based on this model. Our findings are highly significant for both the fundamental study of droplet-mediated crystal growth and the industrial application of integrated single-crystal TMDs.
过渡金属二硫属化物（TMDs）因其独特的光电特性而备受关注。TMD生产阶段的最新进展使我们能够合成具有单层厚度的均匀大面积TMD。阐明生长机制是提高TMD结晶度的一个挑战，这被视为生产阶段的下一个关键课题。在此，我们报告了二硫化钨（WS）生长过程中新型的扩散和成核动力学。通过独特的成核控制方法测量了前驱体的扩散长度（L）。结果表明，L可达约750μm。这种超长扩散可归因于WS生长原位监测过程中观察到的前驱体液滴。基于该模型，在晶圆尺度上实现了>35,000个单晶和单层WS的集成合成。我们的发现对于液滴介导的晶体生长的基础研究和集成单晶TMDs的工业应用都具有重要意义。
