SYNTHESIS OF GRAPHENE/DIAMOND DOUBLE-LAYERED STRUCTURE FOR IMPROVING ELECTRON FIELD EMISSION PROPERTIES

Ultrananocrystalline diamond (UNCD) films on silicon were prepared by microwave plasma chemical vapor deposition (MPCVD) method using argon-rich CH 4 /H 2 /Ar plasmas. The graphene sheets synthesized by chemical vapor deposition (CVD) were successfully transferred on to the UNCD surface to fabricate electron field emission (EFE) property-enhanced graphene/UNCD films. The surface morphology, structure and composition of the graphene/UNCD double-layered structures were characterized by scanning electron microscope (SEM), atomic force microscope (AFM), Raman spectroscopy and grazing incidence X-ray diffraction (GXRD). GXRD clearly shows the characteristic diffraction peaks of both diamond and graphene. The Raman spectrum shows the characteristic band of diamond at 1332[Formula: see text]cm[Formula: see text] and D, G and 2D bands of graphene at 1360, 1550 and 2610[Formula: see text]cm[Formula: see text], respectively. The EFE behavior of the composite films can be turned on at [Formula: see text][Formula: see text]V/[Formula: see text]m, attaining a current density of 0.065[Formula: see text]mA/cm 2 at an applied field of 7.3[Formula: see text]V/[Formula: see text]m.