Method for preparing hexagonal boron nitride film through chemical vapor deposition under normal pressure

According to the method for preparing the hexagonal boron nitride thin film through chemical vapor deposition under the normal pressure, the surface of the copper foil obtained after ultrasonic cleaning, electrochemical polishing, chemical corrosion and high-temperature annealing is smooth and low in roughness and has few nucleation sites, necessary conditions are provided for growth of the large-size and high-quality hexagonal boron nitride thin film H-BN, and the method is suitable for large-scale production of the hexagonal boron nitride thin film. According to the method, a substrate is treated to be in a state suitable for growth of H-BN through reasonable matching of multiple treatment modes, appropriate growth parameters of the H-BN are analyzed and adjusted through analysis of thermodynamics and dynamics in the chemical vapor deposition process, and the large-size and high-quality H-BN is obtained under the normal-pressure environment and the low-airflow condition. Due to low-airflow growth, the use o