Reaction Dynamics Simulation of MoO2 Cluster Precursor with Melting, Deoxygenation and Sulfuration for MoS2 Growth by Chemical Vapor Deposition

Chemical vapor deposition (CVD) is a promising strategy for achieving fascinating large-scale production of MoS2. During CVD, MoO2 exhibits high reactivity and can effectively inhibit intermediate phase formation. Although, the experiments qualitatively demonstrate the MoO2 sulfuration mechanism, the reaction dynamics process on the atomic level is not clear. Herein, according to our previous experimental results of pre-deposited MoO2 vapor-liquid-solid growth MoS2, we investigate microscopic reaction events, including melting, deoxygenation, and sulfuration by reactive molecular dynamics simulation as follow: Terminal oxygen in pre-melting zone on the cluster surface has high reactivity, leading to deoxygenation occurring during melting. The unsaturated coordination Mo atoms are more accessible to sulfuration. With a long simulation time, MoO2 is transformed into MoO0.27S1.95 in which MoS2-like clusters account for up to 92.45 % after annealing. We hope that our work will provide theoretical support for the controlled CVD synthesis of MoS2 and other transition metal dichalcogenides.