Influence of the nitrogen content on the field emission properties of a-CNx films prepared by pulsed laser deposition

Amorphous carbon nitride (a-CNx) films were grown on silicon substrates by ArF excimer laser ablation of a graphite target in the presence of nitrogen at various gas pressures. By working at elevated pressures (up to 100 Pa), high amounts of nitrogen can be incorporated into the films (N/C≤0.4) which lead to strong enhancement of their field emission properties. This behaviour was demonstrated to be mainly related to changes in the surface roughness of the samples, in connection with the development of graphite-like structures.