Product Code: ICAL09_N301

Rapid Growth of Carbon Nanotubes using Laser-induced Chemical Vapor Deposition
Authors:
J. B. Park, Gwangju Institute of Science of Technology; Gwangju South Korea
M. S. Jeong, Advanced Photonics Research Institute; Gwangju South Korea
Sungho Jeong, Gwangju Institute of Science of Technology; Gwangju South Korea
Presented at ICALEO 2009

This paper presents the growth of single-walled (SW) and multi-walled (MW) carbon nanotubes (CNTs) by laser-induced chemical vapor deposition (LCVD) on a transparent substrate at room temperature. For the CNT growth, multiple catalyst layers (Ni/Al/Cr or Fe/Al/Cr) are irradiated from the backside through the transparent substrate with a Nd:YVO4 laser (wavelength=532 nm). The Cr layer in these catalyst configurations plays the role of a thermal layer that converts the incident laser energy into a rather uniformly distributed heat, leading to a uniform growth of CNTs. The direct writing of dense dot and line patterns of MWCNTs below 10 m in size are successfully produced with uniform density on controlled positions. Also, the growth of vertically-aligned MWCNTs (VA-MWCNTs) with 60 m height and 4 m diameter are grown at a high rate of around 1 μm/s with good reproducibility. It is demonstrated that the fabrication of uniform pillar arrays of VA-MWCNTs can be achieved with a single irradiation for each pillar using LCVD with no preprocessing of the substrate. Laser fast-heating is considered the primary mechanism facilitating the observed VA-MWCNT growth. From field-emission measurement, a current density of 318 mA/cm2 is achieved with an array of VA-MWCNT pillars, showing their potential applicability for vacuum electronic devices. By controlling the catalyst thickness and precursor gases, SWCNTs of relatively high density is also produced using this method. Raman analyses of the SWCNT dots revealed that these dots are rich in semiconducting SWCNTs.