2, The Pennsylvania State University, University Park, Pennsylvania, United States
The chemical vapor deposition (CVD) is a powerful technique for synthesizing monolayer materials specifically transition metal dichalcogenides (TMDs). This method has advantages over exfoliation techniques including higher purity and ability to control chemistry of the products. However, controllable and reproducible synthesis of 2D materials using the CVD technique is a challenge, because the complexity of the growth process and its sensitivity to subtle changes in the growth parameters. This will also hinder the extending of the conclusions and growth conditions between different CVD reactors, without exhaustive trial and error experimentations. Here, we developed a generalized multiscale method, where CVD control parameters are linked to morphology, size, and distribution of synthesized 2D materials. The model is further validated experimentally by systematic growth of MoS2, demonstrating its generality and capabilities. Developing this model, we coupled the reactor-scale governing heat and mass transport equations with the mesoscale phase-field equations of the growth, where edge energies vary as a function of precursor concentration within the chamber. Predicted distribution of 2D materials are also statistically analyzed indicating a perfect match with the density of material growth over the substrate. The simulation results indicate an excellent capability developed model for predicting the morphology and thus characteristics of synthesized 2D materials and can be used for designing new CVD chambers, determining the optimum growth conditions, and control of the morphology and characteristics of synthesized 2D materials.