Abstract :
Vertically well-aligned single crystal ZnO nanorod arrays were synthesized and enhanced field electron emission was achieved after radiofrequency
(rf) Ar plasma treatment.With Ar plasma treatment for 30 min, flat tops of the as-grown ZnO nanorods have been etched into sharp tips
without damaging ZnO nanorod geometrical morphologies and crystallinity. After the Ar ion bombardment, the emission current density increases
from 2 to 20 mA cm 2 at 9.0 V mm 1 with a decrease in turn-on voltage from 7.1 to 4.8 V mm 1 at a current density of 1 mA cm 2, which
demonstrates that the field emission of the as-grown ZnO nanorods has been efficiently enhanced. The scanning electron microscopy (SEM)
results, in conjunction with the results of transmission electron microscopy (TEM), Raman spectroscopy and photoluminescence observation, are
used to investigate the mechanisms of the field emission enhancement. It is believed that the enhancements can be mainly attributed to the
sharpening of rod tops, and the decrease of electrostatic screening effect
