Field emissions of graphene films deposited on different substrates by CVD system

Graphene films are deposited on copper (Cu) and aluminum (Al) substrates, respectively, by using microwave plasma chemical vapour deposition technique. Furthermore, these graphene films are characterized by a field emission type scanning electron microscope (FE-SEM), Raman spectra, and field emission (FE) I-V measurements. It is found that the surface morphologies of the films deposited on Cu and Al substrates are different: the field emission property of graphene film deposited on Cu substrate is better than that on Al substrate, and the lowest turn-on field of 2.4 V/μm is obtained for graphene film deposited on Cu substrate. The macroscopic areas of the graphene samples are all above 400 mm².