Effect of length, spacing and morphology of vertically aligned RuO ₂ nanostructures on field-emission properties

The length, spacing and morphology of vertical aligned nanostructural RuO₂ one-dimensional (1D) arrays are varied independently to investigate their effect on the field-emission properties. It is shown that, in general, the lowest turn-on field, highest emission current density and apparent field enhancement factor can be achieved in nanocrystals (NCs) with the smallest emitter radius for the tips and the highest aspect ratio. Moreover, the lower-density NCs exhibit better field-emission characteristics, which are related to the screening effect. The results could be valuable for the application of field-emission-based devices using RuO₂ NCs arrays as cathode materials.