Pulse Field Emission Characteristics of Vertical Few-Layer Graphene Cold Cathode

Vertical few-layer graphene (FLG) is an excellent field emission material, with an atomically thin edge and a 2-D heat dissipation area. A pulse voltage driving operation was used to achieve a high field emission current. The pulsewidth and duty ratio affected the field emission characteristics of the FLG due to the current heating effect. The optimal pulse parameters were obtained. A maximum current of 32 mA in 3- $\mu{\rm s}$ pulsing operation was achieved from a 5-mm diameter FLG film, which was 10 times greater than the maximum current achieved in continuous current operation. The current fluctuation was 4.1%. A method for further increasing the emission current is proposed.