Field Emission Behavior of ZnO Nanowire Planar Cathodes

摘要

Zinc oxide (ZnO) nanowires were deposited on a plane conductive surface. They were vertically aligned, with 3 p and 140 nm respectively for the length and the diameter, and with an array density of 10 nanowires/μm~2. A field emission study by scanning anode field emission microscopy was performed 6' evaluate the field emission properties. The effective work function is about 1 eV, the threshold of the macroscopic field F_(app) is about 6 V/μm for a current density J_(FE) equal to 0.05 A/m~2,which is a rather low field For J_(FE) greater than 500 A/m~2, the nanowires evolved into a bulbous apex by surface diffusion.