Synthesis and field emission properties of aluminum nitride nanocones

One-dimensional aluminum nitride nanostructures have displayed superior field emission due to the combination of small or negative electron affinity and one-dimensional quantum confinement effect. Herein we report on the synthesis of quasi-aligned AlN nanocones via chemical vapor deposition on the Ni-coated silicon wafer at 750 °C through the reaction between AlCl3 vapor and NH3/N2 gas. The as-prepared hexagonal AlN nanocones grow preferentially along c-axis with the tips' sizes of about 60 nm and the lengths up to several microns. The field emission measurement exhibits a notable electron emission with the apparent turn-on field of 17.8 V/μm, indicating their potential applications as the field emitters. Due to space charge effect, the corresponding Fowler-Nordheim plot shows a two-sectional characteristic with the field enhancement factors of 1450 and 340 at low and high electric fields, respectively.