▎ 摘　　要

NOVELTY - A single-crystal grapheme preparation method involves coating hydrocarbon in a metal foil. Thermal decomposition treatment is implemented in the metal foil under vacuum environment or mixed atmosphere of hydrogen and inert gas. The metal foil is cooled to room temperature in the mixed atmosphere of vacuum or hydrogen and inert gas to obtain an outer surface of a single crystal graphene sheet metal, where melting temperature of the metal foil is higher than decomposition temperature of the thermal decomposition treatment. USE - Method for preparing single-crystal graphene in an electronic device. ADVANTAGE - The method enables preparing the single-crystal graphene with high quality and high electron mobility, simplifying a preparation process of the single-crystal graphene, reducing preparation cost of the single-crystal graphene and avoiding generation of pollution during preparation of the single-crystal graphene.