Field emission performance of bulk graphene

Graphene is an upcoming field emission material. However, graphene based thin film devices are prone to irreversible damage, and the stability for long-term operation is poor. In this study, bulk graphene emitter has been proposed for the first time. The emitter was generated by cold pressing using high quality graphene. The novel bulk emitter exhibited an outstanding field emission performance with the turn-on electric field (at 100 μA/cm²) and threshold electric field (at 10 mA/cm²) values determined to be 0.73 V/μm and 1.09 V/μm, respectively, along with a maximum current density of 715.51 mA/cm². Besides, a stable emission of 209.78 mA/cm² was obtained continuously for over 60 h. The self-compensation electron emission mechanism of bulk graphene was proposed based on the morphological changes and simulation results.