▎ 摘　　要

NOVELTY - Preparing graphene field emission source, comprises (i) placing metal substrate into metal lotion, cleaning with acetone, and washing with deionized water, (ii) soaking the washed metal substrate in a hydrochloric acid solution, soaking and washing the deionized water with a metal polishing solution, (iii) placing the metal substrate on the corundum carrier, placing in chemical vapor deposition (CVD) cavity, (iv) vacuuming the cavity, introducing gas hydrogen and carbon-containing gas, (v) heating the base material by electrifying, heating to 1100-1250degrees Celsius for 120-360 minutes, dissolving the carbon atoms in the carbon gas in metal material, (vi) slowly cooling, separating the carbon atom from the metal surface to form a graphene layer by stage cooling, closing the power supply to room temperature, and taking out the metal materials, and (vii) polishing the emitting end of metal material. USE - The graphene field emission source is useful in field emission cathode of electronic device e.g. display device, X-ray tube and negative hydrogen ion source. ADVANTAGE - The graphene field emission source: improves the emission current density of the cathode, and the low opening field and the threshold field; and has excellent stability. The method: is simple; has low energy consumption; is easy to realize industrial production; prepares the emitting component, where the power is higher, the stability is better, and the service life is longer; combines graphene layer with the metal substrate more tightly, where the resistance between the two is far less than the emitter prepared by transferring, when the large current passes through the combined part, the heat productivity is smaller; simultaneously receives the graphene emitting tip exposed of secondary electron reflected by the target; and reduces damage caused by electron or ion of back bombarding emitting tip.