Growth Physics of MoS₂ Layer on the MoS₂ Surface: A Monte Carlo Approach

Layered Transition Metal Dichalcogenides (TMDs) are getting attention due to their layer-dependent tunable optoelectronic and mechanical behavior and the control over the experimental growth technique is required to synthesize deserved stacked products. Alongside, a probabilistic computational approach is necessary to gain deeper insight into the in-situ growth physics. We, therefore, performed Grand Canonical Monte Carlo (GCMC) simulation as implemented in LAMMPS package with ReaxFF potential, and developed our in-house Kinetic Monte Carlo (KMC) code to model the growth physics of MoS₂ layer on the substrate. We considered various pristine and defective growth surface to track the movement of the individual Mo and S. Non-periodic surface with various edge termination (such as chalcogen and metal termination) was also explored. Our Monte Carlo study captures the formation of the MoS₂ on the perfect MoS₂ surface starting with the individual Mo and S flux. We find that the growth temperature plays a crucial role in governing growth mechanisms. Further investigation is on-going on the growth physics of MoS₂ and other TMDs (e.g., WS₂) on pristine and defective substrates. Our modeling approach provides guidelines for the experimentalists for the optimal design of TMD bilayer growth.