Fabrication of three dimensional graphene/carbon nanotube/copper foam field emitter by electrophoretic deposition and its emission properties

Abstract

In this paper, the graphene/carbon nanotubes/copper foam (GR/CNTs/CuF) three-dimensional field emitters were prepared by electrophoretic deposition (EPD). For comparison, the graphene/copper foam (GR/CuF) and carbon nanotubes copper foam (CNTs/CuF) field emitters were also prepared by the same way and characterized by the several different methods. The turn on electrical field (Eon) of composite materials of GR/CNTs/CuF was obtained to be 0.85 V/μm. Threshold electric field (Eth) is 1.52 V/μm. The composite of GR/CNTs/CuF have a large contact area, a lower volume resistance and lower contact resistance, which is more easy to electron transport. The root of the CNTs or the fold tip of GR is fixed in the interlaced composite, and the tip or fold forms a stable micro tip emission structure, which enhanced the field strength factor. The field emission performances are significantly better than that of individual GR/CuF or CNTs/CuF field emitter. The GR/CNTs/CuF as 3D field emitters were prepared by EPD method with low cost and easy manipulation, which provided a good way for a large-scale preparation of composite field emitters.