An internal electric field driving field emission cathode based on graphene

We present a new cathode structure that the field emission current can be modified. A triode structure of graphene cathode with nano-scale sharp folds with two plat electrodes at two sides is presented in which an internal electrical field can be applied across the graphene fold, which is serving as field emission tip, to modulate the field emission. The graphene nano-fold is prepared by transfer an as-grown continuous graphene onto a glass blade-edge, which is obtain by wet etching. The turn-on voltage and work function are 2079v, 1647, 1595v, and 4.60 eV, 1.54 eV, 1.48 eV when the internal electric voltage Ugc are ov, 5v, 10v, respectively (where the turn-on voltage is defined as those required to extract current of 1 uA ). Keep the anode voltage as 2000v, the field emission current increased from 0. 84 μA to 1.94 μA.