Understanding chemical vapor deposition (CVD) growth of MoS$_{\mathrm{2}}$ layers by ReaxFF-molecular dynamics simulations

Recently, mono-layered MoS$_{\mathrm{2}}$ has been widely studied for the next generation of electronic devices. A fundamental understanding of the CVD growth of MoS$_{\mathrm{2}}$ layer is the key to manufacturing a high quality of MoS$_{\mathrm{2}}$-based devices. However, reaction kinetics of the CVD growth of the MoS$_{\mathrm{2}}$ layer has not been fully understood; and synthesis of uniform mono-layered MoS$_{\mathrm{2}}$ up to the wafer-scale is still challenging. This is primarily due to the complexity of the CVD processes ($i.e.,$ intermediate structures from MoO$_{\mathrm{3}}$ to MoS$_{\mathrm{2}}$ phases). Reactive molecular dynamic (MD) simulations can provide atomistic-scale insights into complex surface reactions during the CVD growth. For this reason, our work focuses on developing a ReaxFF reactive force field for MoO$_{\mathrm{3}}$/MoS$_{\mathrm{2}}$/S interactions and performing massively parallel MD simulations of the sulfidation of MoO$_{\mathrm{3}}$ systems. Our goal is to clarify the reaction mechanism of the sulfidation of MoO$_{\mathrm{3}}$ clusters, and provide a theory-supported rational design for not only MoS$_{\mathrm{2}}$-based applications but also for synthesis of other two-dimensional materials.