Stable field emission from tetrapod-like ZnO nanostructures

Abstract

Stable field emission is realized from well-separated tetrapod-like ZnO nanostructures with high purity. The ZnO nanostructures are painted on a highly doped silicon substrate covered by a Au layer with a thickness of $300\mathrm{nm}$ . An emission current density of $18\mathrm{mA}∕{\mathrm{cm}}^2$ is obtained and degradation was not observed over a three day period. The fluctuations of the emission current are less than 2%. These experimental results indicate that tetrapod-like ZnO nanostructures are promising materials as cold cathodes for mass production.