Multi-scale computational approach to understand plasma assisted sulfidation for growth mechanism of MoS₂

The discovery of atomically thin two-dimensional (2D) materials has demonstrated attractive potential as replacements for silicon-based semiconductors, spurring the sustained research efforts into the development of synthesis process. Although chemical vapor deposition (CVD) method has been widely adopted for synthesizing 2D materials owing to its scalability and controllability, plasma assisted sulfidation has also garnered significant attention by overcoming the challenges related to high temperatures and large-scale synthesis. However, despite the outstanding benefits over CVD method, the underlying mechanism for plasma-assisted MoS₂ synthesis is still missing due to the difficulty of approaching plasma behaviors and plasma surface interactions. We present a comprehensive investigation of the mechanism, employing a multiscale simulation framework and supporting experimental validation. Plasma diagnostics are utilized in conjunction with a zero-dimensional (0D) plasma kinetic model to characterize plasma behavior. ReaxFF molecular dynamics (MD) is used to capture atomistic trajectories for simulating plasma solid interactions while density functional theory (DFT) is employed to evaluate adsorption energies and energy pathways using the nudged elastic band (NEB) method. Overall, this integrated research paves the way for the fundamental process governing plasma-assisted synthesis and offers valuable insights into the development of advanced plasma technology for nanomaterial fabrication.