Modelling conduction in carbon nanotube networks with different thickness, chemical treatment and irradiation

Abstract We show how the main features of the electronic transport properties of single-wall carbon nanotube (SWNT) networks can be understood in terms of a simple model involving metallic conduction interrupted by thin tunnelling barriers, backscattering by zone-boundary phonons, and variable range hopping. Within this framework we examine the effect of reducing the thickness of the SWNT networks, chemical treatments, and ion irradiation. The conduction mechanism can be tuned from variable-range hopping between localized states (for the thinnest networks), to metallic conduction interrupted by thin barriers through which conduction is by tunnelling (for thick freestanding films). Chemical treatment of the thick films by different molecules leads to retention of metallic character but changes (increases or decreases) the charge carrier density. For ion-irradiated thick films we find two competing effects: a change to hopping-type conduction in the direct impact layer that lowers conductivity, and annealing effects extending deeper than the ion penetration depth that increase conductivity and lead to a peak in conductivity as a function of irradiation dose. We briefly discuss current–voltage characteristics and possible Luttinger liquid effects.

[1]  A. B. Kaiser,et al.  Thin transparent carbon nanotube networks: effects of ion irradiation , 2007 .

[2]  John R. Reynolds,et al.  Transparent, Conductive Carbon Nanotube Films , 2004, Science.

[3]  Ping Sheng,et al.  Fluctuation-induced tunneling conduction in disordered materials , 1980 .

[4]  A. B. Kaiser,et al.  Ion irradiation effects on conduction in single-wall carbon nanotube networks , 2008 .

[5]  Electronic transport in carbon nanotubes: From individual nanotubes to thin and thick networks , 2006 .

[6]  Dekker,et al.  High-field electrical transport in single-wall carbon nanotubes , 1999, Physical review letters.

[7]  Martel,et al.  Intertube coupling in ropes of single-wall carbon nanotubes , 2000, Physical review letters.

[8]  A. B. Kaiser,et al.  Effect of chemical treatment on electrical conductivity, infrared absorption, and Raman spectra of single-walled carbon nanotubes. , 2005, The journal of physical chemistry. B.

[9]  G. Grüner,et al.  Carbon nanotube films for transparent and plastic electronics , 2006 .

[10]  Liangbing Hu,et al.  Conductivity scaling with bundle length and diameter in single walled carbon nanotube networks , 2006 .

[11]  Kai Nordlund,et al.  Irradiation effects in carbon nanotubes , 2004 .

[12]  Zettl,et al.  Extreme oxygen sensitivity of electronic properties of carbon nanotubes , 2000, Science.

[13]  Bin Zhao,et al.  Electronic properties of single-walled carbon nanotube networks. , 2005, Journal of the American Chemical Society.

[14]  F. Banhart,et al.  The Engineering of Hot Carbon Nanotubes with a Focused Electron Beam , 2004 .

[15]  S. Roth,et al.  Transparent and flexible carbon nanotube/polypyrrole and carbon nanotube/polyaniline pH sensors , 2006 .

[16]  L. Pietronero.  Ideal conductivity of carbon π polymers and intercalation compounds , 1983 .

[17]  Leon Balents,et al.  Luttinger-liquid behaviour in carbon nanotubes , 1998, Nature.

[18]  A. B. Kaiser.  Systematic Conductivity Behavior in Conducting Polymers: Effects of Heterogeneous Disorder , 2001 .

[19]  R. Egger,et al.  Bulk and boundary zero-bias anomaly in multiwall carbon nanotubes. , 2001, Physical review letters.

[20]  G. Grüner,et al.  Transparent and flexible carbon nanotube transistors. , 2005, Nano letters.

[21]  A. B. Kaiser,et al.  Electronic transport properties of conducting polymers and carbon nanotubes , 2001 .

[22]  N. Mott,et al.  Electronic Processes In Non-Crystalline Materials , 1940 .

[23]  W. Whaling,et al.  RANGE OF HEAVY IONS IN SOLIDS , 1962 .

[24]  Zhen Yao,et al.  Carbon nanotube intramolecular junctions , 1999, Nature.

[25]  A. B. Kaiser,et al.  Current-voltage characteristics of conducting polymers and carbon nanotubes , 2005 .

[26]  M. Lundstrom,et al.  Ballistic carbon nanotube field-effect transistors , 2003, Nature.

[27]  John A. Rogers,et al.  p-Channel, n-Channel Thin Film Transistors and p−n Diodes Based on Single Wall Carbon Nanotube Networks , 2004 .

[28]  Masashi Shiraishi,et al.  Conduction mechanisms in single-walled carbon nanotubes , 2002 .

[29]  A. B. Kaiser,et al.  Heterogeneous model for conduction in carbon nanotubes , 1998 .

[30]  H. Dai,et al.  Individual single-wall carbon nanotubes as quantum wires , 1997, Nature.