AVS 56th International Symposium & Exhibition
    Nanometer-scale Science and Technology Monday Sessions
       Session NS+BI-MoA

Paper NS+BI-MoA4
Synthesis of Vertically Aligned and Patterned Silicon-Carbon Core Shell Nanotubes

Monday, November 9, 2009, 3:00 pm, Room L

Session: Nanowires and Nanoparticles II
Presenter: J. Song, Brigham Young University
Authors: J. Song, Brigham Young University
R. Vanfleet, Brigham Young University
R.C. Davis, Brigham Young University
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Here we report the first synthesis of silicon-carbon core-shell nanotubes (SiCNTs). The SiCNTs are formed by coating a vertically aligned and patterned carbon nanotube(CNT) forest with low pressure chemical vapor deposition (LPCVD) of silicon. The carbon nanotube forests were grown from a patterned thin film Fe catalyst resulting in high aspect ratio three dimensional microscale structures up to 500 microns tall with vertical sidewalls. The density of the nanotubes in the forests is very low; the nanotubes fill only about 1 percent of the space by volume. Silicon LPCVD layers (~30 nm thickness) are deposited conformally, coating the nanotubes and significantly increasing the mechanical strength of the structure. By adjusting the silicon deposition temperature, amorphous or crystalline silicon shells can be formed. This combination of silicon LPCVD on VACNTs yields a unique fabrication approach resulting in porous three dimensional silicon structures with precise control over shape and porosity.