Patterned growth and field emission properties of AlN nanocones

AlN is well known for its small (even negative) electron affinity, high stability, and superior thermal conductivity. Recently, various 1D AlN nanostructures such as nanotubes, nanowires, nanobelts and nanocones have been synthesized. Among them, AlN nanocone arrays exhibit good field emission properties due to their sharp apexes, large aspect ratios and well alignment on substrate (1). However, in comparison with carbon nanotubes, the field emission properties of the AlN nanocone arrays were not so promising because of their wide band gap and large density. To further improve the field emission properties of AlN nanocones, two means are worthy of attempt. One is to increase the conductivity of AlN nanocones by doping other elements or constructing composite nanostructures, and the other is to adjust the nanocone density to decrease the screening effect.