Morphology and structure controlled growth of one-dimensional AlN nanorod arrays by hydride vapor phase epitaxy

Well-aligned one-dimensional aluminium nitride (AlN) nanorod arrays were grown on sapphire substrate by hydride vapor phase epitaxy (HVPE) with a temperature range from 750 °C to 900 °C. No template or catalyst was used during the whole procedure. The crystal structure and morphology of the AlN nanorods were investigated by X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopy. All the AlN nanorods were preferentially grown along the c-axis and perpendicular to the sapphire substrate. The morphology of single crystal AlN nanorods was closely related to growth temperature and V/III. Different stages of the growth were studied in detail and a vapor–solid growth mechanism with an anisotropic growth rate caused by limited migration of adatoms on the surface of the substrate explains the formation of AlN nanorods.