The field emission properties of graphene aggregates films deposited on Fe-Cr-Ni alloy substrates

The graphene aggregates films were fabricated directly on Fe-Cr-Ni alloy substrates by microwave plasma chemical vapor deposition system (MPCVD). The source gas was a mixture of H2 and CH4 with flow rates of 100 sccm and 12 sccm, respectively. The micro- and nanostructures of the samples were characterized by Raman scattering spectroscopy, field emission scanning electron microscopy (SEM), and transparent electron microscopy (TEM). The field emission properties of the films weremeasured using a diode structure in a vacuum chamber. The turn-on field was about 1.0 V/µm. The current density of 2.1 mA/cm2 at electric field of 2.4 V/µm was obtained.