Properties of nitrogen-doped diamond-like-carbon films prepared by a laser ablation

Enhanced field emission from nitrogen-doped amorphous diamond

“…According to previous AFM studies, graphitization could dramatically increase surface roughness. 17 The measured AFM images before and after nitrogen addition clearly demonstrate that the addition of N 2 does not change the morphology or roughness of the films. The AFM studies of films are in good agreement with ESCA ( Fig.…”

“…It was previously discussed that the increase of conductivity by nitrogen doping could arise from nitrogen-induced graphitization or the rise of Fermi level in the undoped amorphous diamond from above the valence band to near the conduction band. 14,17 Because the graphitization was not observed in this study, the increasing conductivity of nitrogen-doped films is attributed to the rise of E F in the undoped amorphous diamond from above the valence band to near the conduction band. Veerasamy et al [14][15][16] have demonstrated that nitrogen can act as a donor in tetrahedral amorphous carbon.…”

“…The G peak is associated with the in-plane C-C stretching mode of the sp 2 -hybridized carbon atoms. 17,24,25 The positions of G peaks of nitrogendoped films are shown in Fig. 4(b).…”

“…Hence, it was reported that nitrogen could increase the electrical conductivity and electron emission of amorphous diamondlike carbon films. [13][14][15][16][17] The field emission is typically described by the Fowler-Nordheim (F-N) equation, [18][19][20] which correlates the emission-current density (J, in A/cm 2 ) with the work function (⌽, in eV) and field-enhancement factor (␤) as follows:…”