Comparative Field Emission from Vertically Aligned Few-Layer Graphene and Carbon Nanotubes
Bellucci, Stefano × Malesevic, Alexander Micciulla, Federico Sacco, Immacolata Kemps, Raymond Vanhulsel, Annick Van Haesendonck, Chris #
Amer scientific publishers
Nanoscience and nanotechnology letters vol:3 issue:6 pages:907-912
A comparative study of the electric field emission behaviour of vertically aligned few-layer graphene and carbon nanotubes was evaluated in a parallel plate type setup. Few-layer graphene was synthesized in the absence of any metallic catalyst by microwave plasma enhanced chemical vapour deposition with gas mixtures of methane and hydrogen. The deposit consists of nanostructures that are several micrometers wide, highly crystalline stacks of four to six atomic layers of graphene, aligned vertically to the substrate surface in a high density network. The electric field emission of few-layer graphene was compared to the emission of single-walled carbon nanotubes, as grown multi-walled carbon nanotubes and processed multi-walled carbon nanotubes in the form of buckypaper. The field emission of few-layer graphene is found to be comparable to buckypaper, since both materials are characterized by turn-on fields as low as 2 V/mu m and field amplification factors up to several thousands. As grown single-walled and multi-walled carbon nanotubes reveal remarkable better field emission behaviour when compared to few-layer graphene, with turn-on fields below 1 V/mu m and field amplification factors up to several times the value for few-layer graphene.