Combined effect of nitrogen doping and nanosteps on microcrystalline diamond films for improvement of field emission

•Hot filament chemical vapor deposition using methane, hydrogen and a solution of urea in methanol produced nitrogen-doped diamond films.•Diamonds had the grain morphology changed for long growth time (28h), and the nitrogen doping were evaluated by Raman spectroscopy.•Field emission characterization shows a decrease up to 70% in threshold field, related to reference diamond layer. Nitrogen-doped microcrystalline diamond (N-MCD) films were grown on Si substrates using a hot filament reactor with methanol solution of urea as N source. Electrostatic self-assembly seeding of nanocrystalline diamond were used to obtain continuous and uniform films. Simultaneous changes in grains morphology and work function of diamond by nitrogen doping decreased the threshold field and the angular coefficient of Fowler–Nordhein plots. The field emission properties of our N-MCD films are comparable to carbon nanotube films.