## 5 Conclusions  
In summary, this study provides a comprehensive analysis of the dual-temperature CVD growth process of MoS\({}_{2}\) films, integrating both experimental and simulated approaches to systematically examine the impact of various growth parameters on mass transfer, reaction dynamics, and film growth. The results reveal that during the growth process, the substrate surface exhibits a coexistence of MoS\({}_{6}\) and MoS\({}_{3}\)O\({}_{8}\)S\({}_{4}\). The intermediate product MoS\({}_{3}\)O\({}_{8}\)S\({}_{4}\) not only fails to directly contribute to MoS\({}_{2}\) film growth but also obstructs the diffusion of MoS\({}_{6}\), hindering film formation. When the growth temperature is increased from 1033 K to 1053 K, the diffusion rate of MoS\({}_{6}\) increases, and the inhibitory effect of Mo\({}_{3}\)O\({}_{9}\)S\({}_{4}\) on MoS\({}_{6}\) diffusion decreases, enabling the layered growth of MoS\({}_{2}\) films. Furthermore, lowering the pressure accelerates the convective diffusion rate of dilute species, significantly influencing the location of chemical reactions and the distribution of reaction products, which promotes grain diffusion and growth. This study not only deepens our understanding of mass transfer and reaction processes during MoS\({}_{2}\) growth but also provides valuable insights for the design and optimization of CVD systems. **Supplementary Materials:** The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app15052627/s1](https://www.mdpi.com/article/10.3390/app15052627/s1)]([https://www.mdpi.com/article/10.3390/app15052627/s1](https://www.mdpi.com/article/10.3390/app15052627/s1)), Figure S1: (a) Schematic diagram of the dual-temperature zone CVD system; (b) Concentration of reactants and intermediates as a function of time at a temperature of 1053 K; Figure S2: Flowchart of modeling and calculation processes; Figure S3: XPS data of MoS\({}_{2}\) film grown at 1053 K and 70 Torr; Figure S4: Temperature distribution of the system when the pressure is 70 Torr and the set temperatures in region IV are (a-c) 1033 K, (d-f) 1053 K, and (g-i) 1073 K, where (b, e, h) are the radial cross-sectional views at the center of the substrate, and (c, f, i) are the corresponding local magnifications; Figure S5: Velocity distribution of the system when the pressure is 70 Torr and the temperature in Zone IV is set to (a-c) 1033 K, (d-f) 1053 K, and (g-i) 1073 K, where (b, e, h) are the radial cross-sectional views at the center of the substrate, and (c, f, i) are the corresponding local enlargements; Figure S6: Concentration distribution of S\({}_{2}\) at a pressure of 70 Torr, with the temperature in growth region set to (a) 1033 K, (b) 1053 K, and (c) 1073 K; Figure S7: Radial cross-section of the concentration distribution of reactants and intermediates at the center of the substrate when the temperature in Zone IV is set to 1053 K and the pressure is 70 Torr: (a) Mo\({}_{3}\)O\({}_{9}\)S\({}_{2}\); (b) Mo\({}_{3}\)S\({}_{2}\); (c) Mo\({}_{3}\)S\({}_{4}\); (d) Mo\({}_{2}\)S\({}_{4}\); (e) MoOS\({}_{4}\); (f) MoOS\({}_{6}\); Figure S8: Schematic of MoS\({}_{2}\) film growth on SiO\({}_{2}\)/Si substrate; Figure S9: Temperature distribution of the system at a set temperature of 1053 K in Zone IV, with gas pressures of (a, b) 10 Torr, (c, d) 40 Torr, and (e, f) 100 Torr, where (b, d, f) show radial cross-sectional views at the center position of the substrate; Figure S10: Concentration distribution of S\({}_{2}\) at a temperature of 1053 K in growth region with pressures of (a) 10 Torr, (b) 40 Torr, and (c) 100 Torr; Figure S11: (a) The relationship between Ar gas density and temperature and pressure; (b) The relationship between Ar gas thermal conductivity and temperature; Figure S12: The Reynolds number of the dual-temperature zone CVD when the pressure is 70 Torr and the argon flow rate is 200 sccm. **Author Contributions:** Z.Y. and J.L. contributed equally to this work. Conceptualization, X.S. and X.T. ; simulation, Z.Y., J.L. and Y.L.