Field emission properties of nitrogen incorporated DLC films prepared by electrodeposition

Nitrogen incorporated diamond-like carbon (DLC:N) films with different N content were deposited on Si(1 0 0) substrates by electrolysis of urea/methanol organic solution with different mole ratios under a constant voltage of 600 V. Analysis by Raman spectrometry and X-ray photoelectron spectrometry (XPS) shows that N is incorporated into the DLC films by sp3 C-N and sp2 CN bonds and induces graphitization of the films. The electronic field emission properties of these films have been studied using a parallel plate configuration, and the dependence on N content investigated. The turn-on field (Ec) is lowered with increasing N content, and there is a simultaneous rise in the field emission current densities under the electric field of 23.5 V/μm. Enhancement in field emission is attributed to the donor activity of nitrogen and the field enhancement effect of sp2 clusters.