Position-Controlled, Rapid Growth of Single-walled Carbon Nanotubes
ORAL
Abstract
`Fast-heating' chemical vapor deposition (CVD) is a proven approach for the growth of long individual single-walled carbon nanotubes (SWCNTs). However, obtaining insights into how fast a carbon nanotube can grow is still of scientific and technical importance. Here, we describe a new CVD technique to synthesize SWCNTs using laser irradiation as the heat source. By adjusting the laser conditions, the heating time can be precisely controlled. Additionally, using a laser provides localization of the thermal energy, allowing position controlled growth. Temperature profiles of the substrate, measured by fast, in situ optical pyrometry, show controlled heating to CVD temperatures in a few seconds. Growth rate, yield, and diameter distribution of SWCNTs vary dramatically depending on catalysts, feedstock gases, and heating profile parameters, indicating this laser-CVD technique may provide local control over growth conditions and may pave a way for investigating the growth mechanism of `fast-heating' carbon nanotubes.
*Research on Functional Nanomaterials at ORNL is supported by the U. S. Department of Energy, Division of Materials Science, Basic Energy Sciences.
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