S Precursors*

Layered transition metal dichalcogenides (TMDCs) like MoS₂ layers are promising materials for next-generation electronic applications. Large-area monolayer MoS₂ samples for these applications are typically synthesized by chemical vapor deposition (CVD) using MoO₃ reactants and sulfur precursors. Recent experimental and computational studies have greatly improved our understanding of reaction pathways in CVD synthesis. However, effect of different types of sulfur precursor on CVD synthesis of MoS₂ layer has yet to be fully investigated. Here, we present quantum-mechanically informed and validated reactive molecular dynamics (RMD) simulations to investigate CVD synthesis of MoS₂ layer using S₂ and H₂S molecules. Our goal is to clarify the different sulfidation and reduction rates of MoO₃ surface by S₂ and H₂S precursors.
In this work, we successfully simulated RMD simulations up to 16 ns with a reasonable computing cost. Such a long time-scale simulation allows us to study an atomic scale understanding of the CVD reactions for higher-quality MoS₂ and other TMDCs.