Field emission from carbon nanotube and tetrapod-like ZnO compound cathode fabricated by spin-coating method

We present a study of the field emission properties of a mixture of multi-wall carbon nanotubes (MWCNTs) and tetrapod-like zinc oxide nanostructures (ZTPNs). A spin-coating process instead of screen-printing was used to fabricate the cathode; this prevented largely the destruction of the slim needles of ZTPNs by mechanical rubbing. The protruding needles of ZTPNs in the paste are largely responsible for the field emission, while the CNTs have been added to improve the conductivity of cathode. Ultra low turn-on field at 0.6 V/μm and threshold field at 1.5 V/μm were obtained; moreover, the emission uniformity improved substantially compared to unmixed samples of ZTPN.