▎ 摘　　要

NOVELTY - Improving cleanliness of graphene film comprises subjecting graphene film to high-temperature treatment in vacuum environment, where the temperature of the high temperature treatment is 800-1050degrees Celsius and carrying out chemical vapor deposition method. The growth substrate is provided on the graphene film. The growth substrate is copper foil, nickel foil, copper nickel foil, silicon dioxide or sapphire. USE - The method is useful for improving cleanliness of graphene film. ADVANTAGE - The method: can improve cleanliness of graphene film and the uniformity of cleanliness; and has high temperature processing time of 5-300 minutes and the pressure of the vacuum environment is less than 20 Pa. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for graphene film, prepared by the above method.