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Chemical Vapor Deposition
Chemical vapor deposition (CVD) on catalytically patterned substrates is a method for
carbon nanotube synthesis. The growth process involves heating catalyst
nanoparticles placed at well-defined surface sites on a substrate to high temperatures in
a reactor with flowing hydrocarbon gases. Carbon nanotubes grow from the particles via the
catalytic dissociation of hydrocarbon molecules by the metal particles, and dissolution of carbon
atoms into the particle. Upon saturation, carbon atoms precipitate from the metal particle in a
way that favors the formation of a tubular carbon structure.
The CVD technologies can synthesize both high quality single- and multi-walled carbon nanotubes. A variety of lithographic patterning methods can be used to pattern catalyst particles on various types of substrates. The catalyst sites on the surface provide a means to control the originating locations of nanotubes. The orientation of nanotubes is controlled by either self-assembly or externally applied forces. |
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