Structural Stability of Sulfur-Depleted MoS₂

Transition metal dichalcogenides (TMDs), particularly monolayer MoS₂, have received increased attention in materials science and have been exploited in diverse applications, from photonics to catalysis. Defects in TMDs play a crucial role in modulating their properties, and understanding defect-induced dynamics is of great importance. This study investigates the dynamics of sulfur depletion in defective monolayer MoS₂, which yields stable MoS monolayers. Various defect sizes, temperature regimes (300-1000 K), and substrate effects were investigated. Through comprehensive classical molecular dynamics (CMD) and ab initio molecular dynamics (AIMD) simulations, we elucidate the dynamics of sulfur vacancy formation in MoS₂ lattices. After removal of all sulfur atoms from the top layer, several sulfur atoms from the bottom layer spontaneously migrate to the top layer as a response to increase structural stability, thus creating a MoS _x alloy. These findings deepen our understanding of defect dynamics in TMDs, offering valuable insights into the controlled engineering of their properties for nanotechnology applications.