▎ 摘　　要

NOVELTY - A substrate is ultrasonically-cleaned. Copper target is pre-sputtered. Copper film-deposited substrate is annealed, to obtain polycrystalline copper film substrate. The polycrystalline copper film substrate is heated. Graphene is grown on substrate. The graphene film is transferred, and layer containing poly(methyl methacrylate) is spin-coated with solution containing poly(methyl methacrylate) and anisole. The copper film is etched, and graphene film with layer containing poly(methyl methacrylate) is transferred to target substrate, to obtain graphene thin film. USE - Preparation of graphene thin film (claimed). ADVANTAGE - The method enables economical preparation of graphene thin film at low temperature. DETAILED DESCRIPTION - A substrate is ultrasonically-cleaned with acetone, alcohol and deionized water, and subjected to cavity magnetron sputtering in sputter chamber which is evacuated to predetermined vacuum degree. Copper target is pre-sputtered to remove surface oxidation and contamination, and to deposit copper film with thickness of 1-5 mu m. Copper film-deposited substrate is put in tube furnace and annealed at 900-1050 degrees C for 30-60 minutes in atmosphere containing hydrogen and inert gas, to obtain polycrystalline copper film substrate. When the flow rate of inert gas during annealing is 300-500 sccm, the hydrogen flow rate is 50-100 sccm. The polycrystalline copper film substrate is placed in chemical-vapor-deposition chamber which is evacuated to vacuum degree of 8x 10-4 Pa to 4x 10-4 Pa, and the copper film substrate is heated at 350-450 degrees C in atmosphere containing mixed gas containing 2-5% carbon and hydrogen, and pressure is adjusted to 2-20 Pa, and filament power supply is opened and the filament temperature is adjusted to 1400-2100 degrees C. The radio frequency power supply is adjusted to 0-100 W, and voltage supply to substrate is adjusted to 0-800 V, and graphene is grown for l-10 minutes. The graphene film is transferred, and layer containing poly(methyl methacrylate) is spin-coated with solution containing poly(methyl methacrylate) having mass fraction of 10% and anisole as solvent at rate of 3000 rpm. The copper film is etched, and graphene film with layer containing poly(methyl methacrylate) is transferred to target substrate, and layer containing poly(methyl methacrylate) is removed, to obtain graphene thin film.