Enhanced field emission is observed in nanocrystalline diamond (NCD) films upon irradiation with 100 MeV Ag9+ ions in the range of fluences from 5 × 1010 to 5 × 1011 ions/cm2. Field emission characteristics monotonically changes with the ion beam fluence, but does not show any correlation with sp2 cluster size induced. Enhancement of field emission is presumed to result from the formation of interconnected sp2 cluster network. The turn-on field (E0) for inducing the electron field emission (EFE) has been lowered from 28 to 3.2 V/μm, whereas the EFE current density has been increased from 1.4 × 10− 6 to 2.086 mA/cm2. Such EFE properties are comparable with those of carbon nanotubes.
