Controllable growth of hierarchical AlN nanostructures based on dynamic equilibrium

One-dimensional hierarchical AlN nanostructures comprising a thin nanowire on top of a nanocolumn were synthesized via a vapor–liquid–solid growth mechanism. The abrupt change in the gas flow rate in the growth chamber is responsible for the observed nanostructures. The dynamic equilibrium between absorption and evaporation of the catalyst droplet plays a key role in forming the multilevel nanostructures.