▎ 摘　　要

NOVELTY - Preparation of petal-shaped graphene field emission cold cathode comprises (i) selecting and cleaning the substrate, (ii) selecting the silicon sheet and the copper foil as the substrate respectively, (iii) growing a layer of copper film on the substrate surface in the step (1), (iv) depositing a layer in copper film surface means of thermal evaporation or magnetron sputtering, and (v) using gas phase chemical deposition to obtain the copper film of the silicon sheet substrate surface graphene. USE - Preparation method of petal-shaped graphene field emission cold cathode used for manufacturing field emission cathode in field emission flat panel display (FED), ultra-high frequency tube, terahertz source, X-ray tube and vacuum microelectronic device. ADVANTAGE - The method enables to prepare petal-shaped graphene field emission cold cathode, which exhibits better electron emission performance, stability and reliability, and is compatible with the current semiconductor processing which is good for realizing the integration and miniaturization of the field emitting device, and avoids the adverse effect caused by the transfer process and other indirect preparation method, obtains a kind of shape, and reduces the sound scattering caused by large area contact the graphene and the substrate, which is better for fast conduction of joule heat in field emission process, and improves the stability of the graphene of the cathode field. The field emission test result shows that the product completely satisfies the emission current density required by the field emission plane display device to be more than 1 m A/cm2 and the X-ray tube requires the large current emission index.