Anisotropic growth of aluminum nitride nanostructures for a field emission application

Abstract

One-dimensional single-crystalline AlN nanostructures, which have a tip size of < 20 nm, were synthesized by a HVPE (halide vapor-phase epitaxy) system. The tip size and shape depend on the HCl flow rate. As the HCl flow rate increases, the tip size of the AlN nanostructure decreases. The AlN nanostructures were grown along the c-axis and preferentially oriented with their growth direction perpendicular to the substrate. The morphology and crystallinity of AlN nanorods were characterized by SEM and XRD. The chemical composition was analyzed by energy-dispersive X-ray spectroscopy in the SEM. The field emission measurements show that the turn-on field and field enhancement factor (beta) are 5.6 V/mu m at a field emission current density (J) of 10 mu A/cm(2) and 2092, respectively.