▎ 摘　　要

NOVELTY - Preparing double-layer graphene thin film comprises e.g. taking metal foil/metal thin film as substrate, coating one layer of catalyst on the surface, drying to obtain catalyst and metal complex substrate, placing complex co-catalyst and metal substrate in reaction chamber of chemical gas phase deposition equipment, pumping vacuum, filling hydrogen, thermal insulating, introducing hydrogen and carbon source gas, controlling air pressure, maintaining hydrogen and carbon source gas flow rate, reaction chamber pressure and temperature, and cooling to room temperature. USE - The graphene thin film is used in the field of micro-electronics and photoelectronic device. ADVANTAGE - The method produces double-layer graphene with coverage rate of more than 90%, high controllable graphene layer number, and with fewer defects; has simple process flow; and is suitable for large-scale mass and controllable production of double-layer graphene thin film. DETAILED DESCRIPTION - Preparing double-layer graphene thin film comprises (i) taking metal foil or metal thin film as the substrate, coating one layer of co-catalyst on the surface, then drying at 20-60 degrees C for 2-10 minutes to obtain catalyst and metal complex substrate, where the co-catalyst coating comprises mixed solution comprising 0.03-0.1 g/ml decaborane and anisole, or 97% pure triethyl borate, and the co-catalyst layer coating thickness is 20-150 nm, (ii) placing complex co-catalyst and metal substrate in reaction chamber of chemical gas phase deposition equipment, pumping vacuum at pressure of less than 5x 104 Pa, then filling hydrogen in the reacting chamber so that the air pressure reaches 50-2000 pa, increasing the temperature of the reacting chamber to 850-1000 degrees C, thermal insulating for 10-60 minutes, (iii) maintaining the reaction chamber temperature at 850-1000 degrees C, introducing hydrogen and carbon source gas, where the hydrogen flow rate is controlled at 10-50 sccm, and carbon source gas flow rate is controlled at 10-100 sccm, then controlling air pressure at 150-4000 Pa, thermal insulating for 10-60 minutes, and (iv) maintaining the hydrogen and carbon source gas flow rate, reaction chamber pressure and temperature at 5-100 degrees C, and cooling to room temperature to obtain metal substrate surface deposited double-layer graphene thin film.