Enhanced field emission from ZnO/CNT nanostructure with minimized screening effect

Zinc oxide nanowires (ZNWs) are grown on vertically-aligned carbon nanotubes (CNTs) by vapor phase transport method. Field emission properties of these nanowires have been studied and then compared with similar nanowires fabricated on flat silica substrates. This composed nanostructure has minimized the field-screening effects provoked by the proximity of neighbour tubes. This work demonstrates that the field emission properties were substantially stable at a pressure of 5×10^-6 mbar without exhibiting any current degradation for a constant external field, with an emitting current density of ~1 mA/cm².