Molecular Nanosystems

Core Technologies

Chemical Vapor Deposition

Chemical vapor deposition (CVD) on catalytically patterned substrates is Molecular Nanosystems' patented 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.

Our CVD technologies can synthesize both high quality single- and multi-walled carbon nanotubes. We use a variety of lithographic patterning methods 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.

Main features of our CVD growth technology

Three main advantages of the CVD approach include:

(1) The synthesized nanotube structures tend to be more organized and controlled than those produced by other techniques, such as arc-discharge and laser ablation.

(2) The organization of nanotubes is unsurpassed by any other approach. Their quality and purity are comparable to the best arc-discharge and laser ablation techniques, as verified by microscopy, spectroscopy and electron transport measurements.

(3) True scalability is possible. The growth of massive arrays, or networks of nanotubes, including various ordered multi-walled and single-walled nanotubes, can be synthesized on large surfaces.

The capability of growing carbon nanotubes in a scalable fashion with high yield and reproducibility is the cornerstone of the company's efforts in commercialization of nanotube-based products.