The Fowler-Nordheim plot behaviour from virtual field emitters arrays of zinc oxide nanorods mixed with carbon nanotubes

The Fowler-Nordheim plot behaviour is investigated for large area field emitters arrays composed of mixtures of ZnO nanorods and single-wall carbon nanotubes (CNTs). The field emission current-voltage characteristics are calculated using the Murphy-Good equation based on the Fowler-Nordheim model. The influencing factors taken into consideration are the radii of the ZnO rods, the heights of the CNTs, the variation of the onset voltage of the saturation of the ZnO conduction band (CB) emission current and the degradation of the CNTs at high applied voltages. The results show that the FN plots of the mixed arrays exhibit nonlinear behaviour near the high-field region which could be related to the FN plot behaviour of the constituting emitters arrays. The distribution of the emitters geometrical parameters and the onset of saturation of the ZnO CB current are found to affect the FN plot behaviour of the pure ZnO, CNTs arrays as well as mixed arrays. The comparisons between the FN plots from the present work and those measured experimentally are found useful to shed light on the field emission mechanism. This may in turn aid the development of complex field emission arrays for future technological applications. The work also shows the possibility to apply the standard FN model to complex large area field emitters arrays.