Growth of AlN nanowires by metal organic chemical vapour deposition

AlN nanowires with a diameter of 20 nm were grown stochastically by the vapour-liquid-solid (VLS) method. At low temperatures below 1000 degrees C the Kirkendall effect during the alloying of aluminium and the catalyst resulted in the formation of three-dimensional nanostructures like lamellas and nano flowers. The high temperatures above 1000 degrees C, which are necessary to grow the nanowires complicate the control of their formation. Small catalyst droplets of 20 nm diameter are not stable due to their evaporation. Thus, in contrast to the classical approach to grow a single nano wire out of one droplet, we grew dense networks of nanowires inside larger 3D structures with diameters up to 5 gym. Depending on the growth temperature and the droplet geometry the nanowires inside of these networks are connected by angles of 90 degrees ("cubic") or 120 degrees ("hexagonal").