Morphological effects on the field emission characteristics of zinc oxide nanotetrapods films

Abstract

The direct growth of a tetrapod-like ZnO nanostructure has been accomplished by using a thermal oxidation method without any catalysts. Studies on the field emission properties of the ordered ZnO nanotetrapods films found that the shape of the ZnO nanotetrapods has considerable effect on their field emission properties, especially the turn-on field and the emission current density. Compared with the rod-like legs ZnO nanotetrapods, the nanotetrapods with acicular legs have a lower turn-on field of 2.7 V/µm at a current density of 10 µA/cm 2 , a high field enhancement factor of 1830, and an available stability. More importantly, the emission current density reached 1 mA/cm 2 at a field of 4.8 V/µm without showing saturation. The results could be valuable for using the ZnO nanostructure as a cold-cathode field-emission material.