Multiple Coaxial Carbon Nanotubes of Nitrogen-doped and Boron-doped Multiwalls Prepared by the Template Technique

Introduction With the miniaturization of silicon devices used as semi-conducting devices now appearing its limits, development of other kinds of devices in smaller size (nanodevices) become an urgent task for next generation of electronics devices. Low dimensional carbon materials, especially carbon nanotubes (CNTs), are believed to be one of the most potential candidates for silicon. Constituting carbon based nanoscale diodes and transistors becomes one of main topics in CNTs–based nanoelectronics. Doping of some kinds of foreign elements into CNTs may lead to electron-excess n-type (e.g. N-doped CNTs) or electron-deficient p-type (e.g. B-doped CNTs) semiconducting nanotubes [1]. Provided one can control at nanometer level the position and distribution of such heteroatoms as N and B in CNTs, various types of nano-structured junctions with controlled electronic properties will be possibly prepared. Our group first reported the successful preparation of the double coaxial CNTs of N-doped and undoped multiwalls by the template technique [2]. In this study, we first succeed in the preparation of double and triple coaxial CNTs composed of N-doped and B-doped multiwalls using the template technique.