Low temperature synthesis of single-walled carbon nanotubes in an inductively coupled plasma chemical vapor deposition system.
In this work, we present a parametric study on the low temperature synthesis of single-walled carbon nanotubes (SWNTs) in an inductively coupled plasma (ICP) CVD system using dry bi-layered catalytic thin-films (Fe/Al and Ni/Al, deposited by electron-beam evaporation method) as the catalysts. With a low substrate temperature of 550 degrees C and above, SWNTs were successfully synthesized on both catalysts, as revealed from the characteristic peaks of SWNTs in the micro-Raman spectra. By the reduction of plasma power and the shortening of the process times, the lowest synthesis temperature of SWNTs achieved in our system was approached to 500 degrees C on Ni/Al catalysts; on the other hands, the lowest temperature for Fe/Al catalysts was 550 degrees C. Our results suggest that as compared with Fe/Al, Ni/Al is more favorable for plasma-enhanced CVD (PECVD) synthesis of SWNTs at low temperatures. This work can be used for further improvements and better understanding on the production processes of SWNTs by PECVD methods.
Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan, R. O. China.
Cheng-Hui
CH
Weng
Chao-Shun
CS
Yang
Hsuan
H
Lin
Chuen-Horng
CH
Tsai
Keh-Chyang
KC
Leou