Modeling of convective transport in crystallization of gallium nitride by basic ammonothermal method

• Published in: Journal of crystal growth Vol. 627; p. 127525
• Main Authors: Zak, Marek, Kempisty, Pawel, Lucznik, Boleslaw, Grabianska, Karolina, Kucharski, Robert, Iwinska, Malgorzata, Bockowski, Michal
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2024
• Subjects: A1. Computer simulation; A1. Fluid flows; A2. Growth from solutions; Semiconducting III-V materials; Semiconducting III-V materials; A1. Computer simulation; A2. Growth from solutions; A1. Fluid flows
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2023.127525

•Industrial scale autoclave shows high probability of turbulent flow.•Temperature distribution plays important role in crystals quality.•Uniform velocity distribution gives better growth condition.•Smaller velocity values seems to be better for high quality crystals.•Installation can be optimized based on velocity and temperature distribution. The most important parameter affecting the surface morphology of the growing crystal and its structural quality is supersaturation at the crystallization front. In the case of ammonothermal growth of gallium nitride, supersaturation is fully related to convective mass transport. Due to technological limitations and extreme crystallization conditions it is problematic to obtain detailed information about the internal processes in the growth experiments, especially the convective flow. The solution to this problem is to use the Computational Fluid Dynamics method to model the processes occurring inside autoclaves. This paper presents a quantitative analysis of convective transport in a three-dimensional approximation during the ammonothermal crystallization of gallium nitride. ANSYS Academic Computational Fluid Dynamics simulation software was used. The simulation results obtained were referenced and compared with the experimental results: thickness and structural quality of the gallium nitride crystals.