Factors determining properties of multi-walled carbon nanotubes/fibres deposited by PECVD

This paper presents a number of factors which have been found to be important to the growth of carbon nanotubes and nanofibres by plasma enhanced chemical vapour deposition. The effect of the electric field in a plasma discharge on nanotube growth is investigated and shown to be important in achieving nanotube alignment. The use of a plasma discharge also enables deposition to take place at lower temperatures, facilitating the use of substrates which would otherwise be damaged. The effect of varying the ratio of carbon feedstock gas to etchant gas is investigated and the ratio is shown to be important for controlling the shape of deposited nanostructures. The effects of varying plasma power are investigated, showing that greater plasma power results in a lower growth rate. Higher levels of plasma power are also shown to cause the sidewalls of deposited carbon nanotubes to be etched. Finally, the growth rate of carbon nanotubes and nanofibres is shown to depend upon the strength of the local electric field. It is proposed that a higher field causes greater ionization within the plasma, which results in a higher growth rate. This is borne out by comparing simulation results with experimental observations.

[1]  Otto Zhou,et al.  Plasma-induced alignment of carbon nanotubes , 2000 .

[2]  Gehan A. J. Amaratunga,et al.  Plasma composition during plasma-enhanced chemical vapor deposition of carbon nanotubes , 2004 .

[3]  Seong Chu Lim,et al.  Effect of surface morphology of Ni thin film on the growth of aligned carbon nanotubes by microwave plasma-enhanced chemical vapor deposition , 2000 .

[4]  H. Dai,et al.  Self-oriented regular arrays of carbon nanotubes and their field emission properties , 1999, Science.

[5]  W. I. Milne,et al.  Carbon nanotubes by plasma-enhanced chemical vapor deposition , 2006 .

[6]  G. Amaratunga,et al.  Characterization of plasma-enhanced chemical vapor deposition carbon nanotubes by Auger electron spectroscopy , 2002 .

[7]  M. Meyyappan,et al.  Growth of carbon nanotubes by thermal and plasma chemical vapour deposition processes and applications in microscopy , 2002 .

[8]  W. K. Maser,et al.  Large-scale production of single-walled carbon nanotubes by the electric-arc technique , 1997, Nature.

[9]  M. Meyyappan,et al.  Combinatorial Optimization of Heterogeneous Catalysts Used in the Growth of Carbon Nanotubes , 2001 .

[10]  Sungho Jin,et al.  In situ-grown carbon nanotube array with excellent field emission characteristics , 2000 .

[11]  R. J. Waite,et al.  Nucleation and growth of carbon deposits from the nickel catalyzed decomposition of acetylene , 1972 .

[12]  S. Iijima.  Helical microtubules of graphitic carbon , 1991, Nature.

[13]  I. Han,et al.  In situ diagnosis of chemical species for the growth of carbon nanotubes in microwave plasma-enhanced chemical vapor deposition , 2002 .

[14]  Gehan A. J. Amaratunga,et al.  The Significance of Plasma Heating in Carbon Nanotube and Nanofiber Growth , 2004 .

[15]  M. Siegal,et al.  Synthesis of large arrays of well-aligned carbon nanotubes on glass , 1998, Science.

[16]  Sajad Haq,et al.  Large-area synthesis of carbon nanofibres at room temperature , 2002, Nature materials.

[17]  Vladimir I. Merkulov,et al.  Patterned growth of individual and multiple vertically aligned carbon nanofibers , 2000 .

[18]  John Robertson,et al.  Growth process conditions of vertically aligned carbon nanotubes using plasma enhanced chemical vapor deposition , 2001 .

[19]  M. Meyyappan,et al.  Reactor design considerations in the hot filament/direct current plasma synthesis of carbon nanofibers , 2003 .

[20]  J. Remacle,et al.  Gmsh: A 3‐D finite element mesh generator with built‐in pre‐ and post‐processing facilities , 2009 .

[21]  Sungho Jin,et al.  Nucleation and growth of carbon nanotubes by microwave plasma chemical vapor deposition , 2000 .

[22]  L. Delzeit,et al.  Electronic properties of multiwalled carbon nanotubes in an embedded vertical array , 2002 .

[23]  Young Hee Lee,et al.  Crystalline Ropes of Metallic Carbon Nanotubes , 1996, Science.

[24]  W. Krätschmer,et al.  Solid C60: a new form of carbon , 1990, Nature.

[25]  G. Park,et al.  Growth of carbon nanotubes by microwave plasma-enhanced chemical vapor deposition at low temperature , 2000 .

[26]  P. Ajayan,et al.  Large-scale synthesis of carbon nanotubes , 1992, Nature.

[27]  Christophe Geuzaine,et al.  Gmsh: A 3‐D finite element mesh generator with built‐in pre‐ and post‐processing facilities , 2009 .

[28]  M. Meyyappan,et al.  Growth of multiwall carbon nanotubes in an inductively coupled plasma reactor , 2002 .