Arrays of Ni nanowire/multiwalled carbon nanotube/amorphous carbon nanotube heterojunctions containing Schottky contacts

Ordered arrays of heterojunctions comprising Ni nanowires, multiwalled carbon nanotubes, and amorphous carbon nanotubes (a-CNTs) connected end to end were fabricated. The current-voltage (I-V) characteristics of the heterojunctions embedded in the arrays were measured by a conductive atomic force microscope. It was found that although the electrical signals of Schottky contacts in some heterojunctions were buried by those of the long a-CNT segments, Schottky contacts in the other heterojunctions played a central role and made the corresponding heterojunctions possess rectifying I-V characteristics. The quantitative analysis showed that the thermionic emission theory was applicable to Schottky contacts in one-dimensional heterojunctions. (c) 2007 American Institute of Physics.