The synthesis of MWNTs/SWNTs multiple phase nanowire arrays in porous anodic aluminum oxide templates

In order to utilize the unique properties of carbon nanotubes (CNTs) in microelectronic devices, the special hetero-junction or multiple phase structure of multi-walled carbon nanotubes (MWNTs) and single-walled carbon nanotubes (SWNTs) array has been produced by chemical vapor deposition (CVD) method in porous anodic aluminum oxide (AAO) templates. The approach involves CVD process, fabrication of catalytic nanoparticle, and nanotube interconnection for orientation. The synthesized MWNT/SWNT hetero-junctions or multiple phase nanowire arrays were fully characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectrum. The multiple phase structures have the one-dimensional features of CNTs and build an ideal semiconductor–metal or metal–metal hetero-junction nanowire in the axial direction. The structural character and growing mechanism of MWNT/SWNT hetero-junctions or multiple phase nanowire arrays were also analyzed and discussed.