Univ. Grenoble Alpes, FR-38000 Grenoble, CEA, LETI, Minatec Campus, FR-38054 Grenoble Cedex 9, France.
Université de Lyon, C2P2 - UMR 5265 (CNRS - Université de Lyon 1 - CPE Lyon), Équipe Chimie Organométallique de Surface CPE Lyon, 43 Boulevard du 11 Novembre 1918, FR-69616 Villeurbanne Cedex, France.
Nanoscale. 2017 Jan 5;9(2):538-546. doi: 10.1039/c6nr06021h.
The lack of scalable-methods for the growth of 2D MoS crystals, an identified emerging material with applications ranging from electronics to energy storage, is a current bottleneck against its large-scale deployment. We report here a two-step ALD route with new organometallic precursors, Mo(NMe) and 1,2-ethanedithiol (HS(CH)SH) which consists in the layer-by-layer deposition of an amorphous surface Mo(iv) thiolate at 50 °C, followed by a subsequent annealing at higher temperature leading to ultra-thin MoS nanocrystals (∼20 nm-large) in the 1-2 monolayer range. In contrast to the usual high-temperature growth of 2D dichalcogenides, where nucleation is the key parameter to control both thickness and uniformity, our novel two-step ALD approach enables chemical control over these two parameters, the growth of 2D MoS crystals upon annealing being ensured by spatial confinement and facilitated by the formation of a buffer oxysulfide interlayer.
二维 MoS 晶体的生长缺乏可扩展的方法，而这种新兴材料在电子学和储能等领域都有应用，这是其大规模应用的当前瓶颈。我们在这里报告了一种两步原子层沉积（ALD）方法，使用了新的有机金属前体 Mo(NMe) 和 1,2-乙二硫醇（HS(CH)SH），它包括在 50°C 下逐层沉积无定形表面 Mo(iv) 硫醇，然后在更高温度下进行后续退火，从而在 1-2 单层范围内得到超薄的 MoS 纳米晶体（约 20nm 大小）。与通常的二维二卤化物的高温生长不同，其中成核是控制厚度和均匀性的关键参数，我们的新型两步 ALD 方法可以实现对这两个参数的化学控制，通过空间限制和形成缓冲氧硫化物中间层来促进二维 MoS 晶体的生长。
