Formation and field emission characteristics of nitrogen plasma-treated titanium dioxide clusters

Nitrogen plasma treatment was used to enhance the field emission (FE) properties of titanium dioxide (TiO2) clusters and form nitrogen doped TiO2 (N-doped TiO2) on the TiO2 clusters. The TiO2 clusters were grown directly onto the Fe/Al/Ti sheet using atmospheric annealing. The N-doped TiO2 content was controlled using the nitrogen plasma treatment time. Because continuous nitrogen plasma treatment damages the N-doped TiO2/TiO2 cluster surface, increasing the N-doped TiO2 content could not continually improve the FE current density. A balance between the N-doped TiO2 content and surface damage must be reached to attain a relatively higher FE current density. The FE characteristics are discussed with regard to the N-doped TiO2 content and the cluster surface morphologies. An optimal nitrogen plasma treatment time of 60 min was developed in this study to attain the highest FE current density.