▎ 摘　　要

NOVELTY - The graphene-like material comprises graphene located on one surface or two surfaces of insulating substrate. The thickness of the graphene is 150-250 atomic layers. The modified preparation method of graphene material involves putting the insulating substrate in chemical vapor deposition system, introducing carbon source and nitrogen source, depositing at 900-1100 ℃, cooling to room temperature to obtain the modified graphene material. The carbon source is ethanol. The growth condition of the modified graphene material is controlled by gradient method to prepare graphene material with ultra-low wrinkle density. The gradient method comprises low temperature phase, temperature rising stage, and high temperature phase. USE - Graphene-like material with insulating heat-conducting function for use in electronic device. ADVANTAGE - The modified graphene material has good insulating and heat conducting performance, improves the material performance of the graphene material. The growth process of graphene is carried out on the insulating substrate, can obtain 1-3 layers of graphene material, no need to transfer the material to be obtained, can be directly applied to the electronic device. The condition of each step by gradient control, the invention realizes the accurate control of the nucleation and growth speed of graphene, uniformly distributed on the substrate, the wrinkle density can be reduced to 1 × 10- 5/μm2or less. DETAILED DESCRIPTION - The graphene-like material comprises graphene located on one surface or two surfaces of insulating substrate. The thickness of the graphene is 150-250 atomic layers. The modified preparation method of graphene material involves putting the insulating substrate in chemical vapor deposition system, introducing carbon source and nitrogen source, depositing at 900-1100 ℃, cooling to room temperature to obtain the modified graphene material. The carbon source is ethanol. The growth condition of the modified graphene material is controlled by gradient method to prepare graphene material with ultra-low wrinkle density. The gradient method comprises low temperature phase, in which growth temperature is 900-1500 ℃, gaseous carbon source flow is 0.001-0.02 L/minute, hydrogen flow is 1-25 L/minute, C/H ratio is 0.01-0.1 %, nitrogen flow is 0.5-1 L/minute, gas pressure is 500-1000 mbar, and duration is 1-25 minutes, temperature rising stage comprising raising the temperature at a constant speed of 31-250 ℃ in 5-15 minutes, keeping the flow of the gaseous carbon source unchanged, reducing the hydrogen flow, raising the C/H ratio to 0.2-1 %, reducing the constant speed of the nitrogen flow to 0.05-0.3 L/minute, and reducing the gas pressure at a constant speed 100-400 mbar, and high temperature phase, in which the low temperature stage temperature difference is 31-250 ℃, the gaseous carbon source flow is kept unchanged, C/H ratio is 0.2-1 %, the nitrogen flow is 0.05-0.3 L/minute, the gas pressure is 100-400 mbar, and the duration is 10-60 minute, where the C/H ratio is the flow ratio of the carbon source and the hydrogen.