Controlled growth of aluminium nitride nanorod arrays via chemical vapour deposition

Large-area and high-density arrays of AlN nanorods were synthesized at low temperature via a template-free and catalyst-free chemical vapour deposition. The quasi-aligned AlN nanorods were identified to grow along the c-axis and preferentially orient with their growth direction perpendicular to the substrate. Further studies showed that the AlN nanorods were grown on a buffer layer formed at the beginning of the reaction. By changing the flow rate of the carrier gas at the beginning of the reaction, we successfully obtained nanorods with different orientations on the substrate. The Raman spectrum and cathodoluminescence spectrum of the AlN nanorods at room temperature reveal the existence of oxygen-related defects in the nanorods.