Nitrogen doped reduced graphene oxide: Investigations on electronic properties using X-ray and Ultra-violet photoelectron spectroscopy and field electron emission behaviour

Abstract

The practice of heteroatom doping has been proven to significantly enhance the intrinsic properties of host materials. A facile, one-step process due to the thermal reduction of ammonium hydroxide-treated graphene oxide (GO) was employed to yield nitrogen (N) doped reduced graphene oxide (rGO). In-depth characterization has been performed to reveal the phase, structure, morphology, and electronic properties of as-synthesized products. It is observed that the processing temperature noticeably affects the concentration and type of doped N species. The N-doped rGO (N-rGO) prepared at 900 ℃ exhibited excellent field electron emission (FEE) performance with relatively lower values of turn-on and threshold fields ∼ 1.28 and 1.52 V/µm, defined at emission current densities of 10 and 100 µA/cm2, respectively. Furthermore, a high current density of 5.83 mA/cm2 was drawn at an applied field of 2.51 V/µm, and the emitter showed equitably current stability tested at 10 µA. The obtained results promote the N-rGO emitter, with tuned concentrations of doped N-species, as a promising candidate for practical applications in various vacuum microelectronic devices.