Experimental and theoretical investigation on pre-deposited precursor as growth sites for monolayer MoS2 growth by supercritical fluid deposition

• Published in: Chemical engineering science 2025-02, Vol.302, p.120782, Article 120782
• Main Authors: Wang, Qi-Bo, Xu, Qin-Qin, Han, Zhen-Hua, Yang, Ming-Zhe, Yin, Jian-Zhong, Xia, Xiao-Chuan
• Format: Article
• Language: English
• Subjects: Chemical vapor deposition; Growth mechanism; MoS2; Supercritical CO2; Supercritical fluid deposition
• ISSN: 0009-2509
• DOI: 10.1016/j.ces.2024.120782

[Display omitted] •Mo(CO)6 is as nucleation site to grow MoS2 film by supercritical fluid deposition.•MoS2 domains size and coverage can be tuned.•Homogeneous and heterogeneous sulfuration reactions promote synthesis of MoS2.•Mo obtained by decarbonylation of Mo(CO)6 has a high reactivity by DFT analysis. The assistance of promoters, Molybdates or alkali metal salts can regulate the nucleation site of MoS2 in chemical vapor deposition. However, the introduction of impurities inevitably reduces the MoS2 quality. Here, we present the growth of monolayer MoS2 by supercritical fluid deposition to pre-deposit Mo(CO)6 precursors as nucleation sites, replacing difficult to clean conventional promoters. Domain-limited homogeneous and heterogeneous reactions occur at nucleation sites, and through optimization of sulfurization parameters, high-quality monolayer MoS2 with about 20 μm domain size can be obtained by growing at 760 °C and 40 sccm argon for 20 min. Monolayer MoS2 coverage ranged from 2.6 % to 39.1 % by regulating dissolution mass in range of 100–400 mg, utilizing the highly soluble Mo(CO)6 in supercritical CO2. Density functional theory calculations show that decarbonylated Mo(CO)6 possesses higher sulfide reactivity. This study provides new insights into the impurity-free controlled site growth of two-dimensional materials.