▎ 摘　　要

NOVELTY - Gallium nitride crystals preparation involves preparing graphene nanosheet, where concentration of graphene oxide is 0.005-0.1 mg/ml. The nanosheet (0.001-0.02mg/ml) is dispersed in a solution of N,N-dimethylformamide or N-methyl pyrrolidone to obtain oxidized graphene nanosheet, which is later dispersed in water. The prepared graphene nanosheet is utilized for upper substrate preparation of gallium nitride crystals. The prepared graphene nanosheet is dried at 80-200 degrees C for 1-8 hours and is subjected to hydride vapor phase epitaxy method to obtain desired product. USE - Method for preparing gallium nitride crystals (claimed). ADVANTAGE - The method is suitable for large scale production of gallium nitride crystals in a convenient and cost-effective manner.