▎ 摘　　要

Ultrananocrystalline diamond (UNCD) films on silicon were prepared by microwave plasma chemical vapor deposition (MPCVD) method using argon-rich CH4/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 cm(-1) and D, G and 2D bands of graphene at 1360, 1550 and 2610 cm(-1), respectively. The EFE behavior of the composite films can be turned on at E-0 = 2.2 V/mu m, attaining a current density of 0.065 mA/cm(2) at an applied field of 7.3 V/mu m.