Enhanced field emission properties of graphene composite films by introducing graphene oxide

Abstract

Graphene films are composed of graphene layers that exhibit high levels of order, thereby enabling their use as aligned emission arrays. However, the limitations of the film are attributable to its electric field shielding effect, which is a consequence of the severe π–π stacking. In this study, the stacking was mitigated by incorporating graphene oxide, thereby enhancing the field emission performance of graphene composite films. Graphene oxide has the capacity to modify the interlayer spacing of the film, as well as the morphology of its cross section, when subjected to heat treatment. The combination of these two factors results in a reduction of the electric field shielding effect and an enhancement of the field emission performance. The efficacy of this method is substantiated by a reduction in turn-on and threshold field strengths from 2.34 and 3.35 V/μm to 1.27 and 2.43 V/μm, respectively. Additionally, an enhancement in the field enhancement factor from 4306 to 11 396 has been observed. The slope of the linear fit voltage over time for films has been determined to be 0.001 kV/h at 3 mA@50 kA/cm2. The field emission performance of these film emitters offers valuable insights, providing a foundation for exploring potential applications.