Tailoring Carbon Nanotubes to Designed Morphologies for Electron Field Emission Applications

Field emission from carbon nanotubes (CNTs) at low applied electric fields has been demonstrated by a number of groups. However, the emission behavior reported for CNTs varies widely. Most of this variation is attributed to differences in the nanotube morphologies and contents of measured samples. We report here the effect of fabrication techniques including thermal chemical vapor deposition (CVD) and plasma enhanced CVD on the formation of CNTs. The post-deposition process of using atomic layer deposition (ALD) of ZnO on CNTs was also investigated. The results suggest that numerous ZnO "nanobeads" formed on the surface of the CNTs resulting in dramatically improved electron field-emission