▎ 摘　　要

NOVELTY - A controllable layer number graphene thin film is prepared by (A) preparing germanium-silicon substrate; (B) carburizing; and (C) heating copper-nickel composite substrate with carbon source gas at 300-1000 degrees C, introducing carrier gas and performing heat preservation for 10-180 minutes to obtain desired graphene film. The step (A) comprises forming a layer of metal nickel layer on surface of copper foil to obtain nickel-copper composite substrate. The carburizing step comprises heating copper-nickel composite substrate at 200-300 degrees C and carrying out carburizing for nickel layer. USE - Controllable layer number graphene thin film. ADVANTAGE - The thin film solves the problem that composite substrate has high cost. Layer number of graphene is controlled more easily. The preparation method is simple and easy to control, has good product quality, and has large area graphene film material. DETAILED DESCRIPTION - Controllable layer number graphene thin film is prepared by (A) preparing germanium-silicon substrate; (B) carburizing; and (C) heating copper-nickel composite substrate with carbon source gas at 300-1000 degrees C, continuously introducing carrier gas and performing heat preservation for 10-180 minutes to obtain desired graphene film. The step (A) comprises forming a layer of metal nickel layer on surface of copper foil to obtain nickel-copper composite substrate. The carburizing step comprises heating copper-nickel composite substrate at 200-300 degrees C, introducing carbon source gas and carrier gas, performing heat preservation for 30-240 minutes, and carrying out carburizing for nickel layer.