Comparison of field emission of carbon, carbon nitride and boron carbon nitride nanotubes

Carbon,CN x and BCN nanotubes were synthesized by pyrolysis at 860℃ and purified. Thin films of the purified samples were fabricated by a screen-printing method. The field emission effect of these films was compared. It was found that the turn-on field was 2.22，1.1 and 4.4V/μm,and the current density at 5.7V/μm was 1400，3000 and ＜50μA/cm 2 for C, CN x and BCN nanotubes,respectively. The electron field emission property of the CN x nanotubes was better than the carbon nanotubes while that of BCN nanotubes was the worst. The origin of the differences in field emission of these films was explained.