Field emission from open ended aluminum nitride nanotubes

TLDR

The study reports field‑emission measurements of aluminum nitride nanotubes synthesized by gas‑phase condensation. The authors produced AlN vapors in a dc arc plasma reactor, mixed the resulting nanotubes with AlN nanoparticles, and coated tungsten tips with the mixture to serve as field emitters. Field‑emission measurements revealed sharp, shape‑changing ring patterns attributed to open‑ended AlN nanotubes, dot patterns from nanoparticles, nonlinear Fowler–Nordheim behavior indicating semi‑insulating emitters, and a high field‑enhancement factor of 34 500.

Abstract

This letter reports the field emission measurements from the nanotubes of aluminum nitride which were synthesized by gas phase condensation using the solid-vapor equilibria. A dc arc plasma reactor was used for producing the vapors of aluminum in a reactive nitrogen atmosphere. Nanoparticles and nanotubes of aluminum nitride were first characterized by transmission electron microscope and tube dimensions were found to be varying from 30 to 200 nm in diameter and 500 to 700 nm in length. These tubes were mixed with nanoparticles of size range between 5 and 200 nm in diameter. Tungsten tips coated with these nanoparticles and tubes were used as a field emitter. The field emission patterns display very interesting features consisting of sharp rings which were often found to change their shapes. The patterns are attributed to the open ended nanotubes of aluminum nitride. A few dot patterns corresponding to the nanoparticles were also seen to occur. The Fowler–Nordheim plots were seen to be nonlinear in nature, which reflects the semi-insulating behavior of the emitter. The field enhancement factor is estimated to be 34 500 indicating that the field enhancement due to the nanometric size of the emitter is an important cause for the observed emission.