Influence of the deposition conditions on the field emission properties of patterned nitrogenated carbon nanotube films

The electron field emission of patterned films of nitrogenated carbon nanotubes is shown to be decisively influenced by the deposition conditions. The growth was carried out by decomposing methane in a nitrogen/ammonia atmosphere using hot filament chemical vapor deposition (CVD). The diameter of the produced tubes depended critically on the distance between substrate and filament, and the field emission properties (applied fields needed for electron emission, field amplification factor) could be directly correlated to the film morphology. This demonstrates the possibility of tuning the field emission properties of such film emitters. For arrays of nanotubes thinner than 50 nm, the onset of field emission was observed at ∼4 V/μm, and a current density of 10 mA/cm2 was obtained for an applied field of 7.2 V/μm.