Based on the actual hot zone structure of an AlN crystal growth resistance furnace, the global numerical simulation on the heat transfer process in the AlN crystal growth was performed. The influence of different heater structures on the growth of AlN crystals was investigated. It was found that the top heater can effectively reduce the axial temperature gradient, and the side heater 2 has a similar effect on the axial gradient, but the effect feedback is slightly weaker. The axial temperature gradient tends to increase when the bottom heater is added to the furnace, and the adjustable range of the axial temperature gradient of the side 1 heater + bottom heater mode is the largest. Our work will provide important reference values for AlN crystal growth by the resistance method.

Monocrystalline graphene growth has always been an intriguing research focus. Argon (Ar) is merely viewed as a carrier gas due to its inert chemical properties throughout the whole growth procedure by the chemical vapor deposition method. In this work, the influence of Ar on temperature and flow fields was investigated in consideration of its physical parameter difference among all involved gases. Results by experimental characterization and fluid dynamics simulation showed that the temperature elevated, and the velocity of the mixed gas increased as the Ar flow rates rose. Furthermore, the deposition rate of C on the Cu surface, representing graphene generation rate, was studied as the Ar flow rate changed in combination with CH₄ decomposition reaction. Based on the effects made by Ar, a method was proposed, where the Ar flow rate was dynamically regulated to break monocrystalline graphene growth cessation. The graphene size was enlarged, and the nucleation site density was reduced remarkably compared with a common consistent Ar flow. It is believed that this work would provide a new perspective in two-dimensional material preparation by combining basic properties with temperature and field distribution in the whole reaction system.