The relationship between network morphology and conductivity in nanotube films

Lyons, Philip E.; De, Sourya Joyee; Blighe, Fiona M.; Nicolosi, Valeria; Pereira, Luiz Felipe C.; Ferreira, M. S.; Coleman, Jonathan N.

doi:10.1063/1.2968437

Cited by 128 publications

(139 citation statements)

References 30 publications

Supporting

Mentioning

128

Contrasting

Order By: Relevance

“…In combination with experimental measurements, the model described above has been used to estimate the inter-tube junction resistance [8]. The result obtained is in broad agreement with independent experimental results [18,19].…”

Section: Applicationsupporting

confidence: 72%

“…We again see an increase in the overall film conductance as the aspect ratio of individual nanotubes is increased. Moreover, the model reproduces the approximate linear trend observed in experimental reports [8].…”

Section: Multiscale Model Of Cnt Networksupporting

confidence: 61%

“…In practice, equations (1) and (2) provide numerical values for the connectivity and for the number of connections to the electrodes in a model network film, for any set of parameters chosen. Furthermore, the expressions obtained for α and α E can be used in combination with experimental data in order to estimate physical properties of real carbon nanotube films [8]. Finally, equations (1) and (2) can also be coupled with electronic transport models to provide calculations for the electrical conductivity of network films.…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Electronic transport on carbon nanotube networks: A multiscale computational approach

Pereira

Ferreira

2011

Nano Communication Networks

View full text Add to dashboard Cite

Carbon nanotube networks are one of the candidate materials to function as malleable, transparent, conducting films, with the technologically promising application of being used as flexible electronic displays. Nanotubes disorderly distributed in a film offers many possible paths for charge carriers to travel across the entire system, but the theoretical description of how this charge transport occurs is rather challenging for involving a combination of intrinsic nanotube properties with network morphology aspects. Here we attempt to describe the transport properties of such films in two different length scales. Firstly, from a purely macroscopic point of view we carry out a geometrical analysis that shows how the network connectivity depends on the nanotube concentration and on their respective aspect ratio. Once this is done, we are able to calculate the resistivity of a heavily disordered networked film. Comparison with experiment offers us a way to infer about the junction resistance between neighbouring nanotubes. Furthermore, in order to guide the frantic search for high-conductivity films of nanotube networks, we turn to the microscopic scale where we have developed a computationally efficient way for calculating the ballistic transport across these networks. While the ballistic transport is probably not capable of describing the observed transport properties of these films, it is undoubtedly useful in establishing an upper value for their conductivity. This can serve as a guideline in how much room there is for improving the conductivity of such networks.

show abstract

Section: Applicationsupporting

confidence: 72%

Section: Multiscale Model Of Cnt Networksupporting

confidence: 61%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Electronic transport on carbon nanotube networks: A multiscale computational approach

Pereira

Ferreira

2011

Nano Communication Networks

View full text Add to dashboard Cite

show abstract

“…In fact, we have recently demonstrated how sensitive to the network connectivity the conductivity can be. 12 This means that no matter how much progress is made in lowering the junction resistance, there should be a maximum value for the film conductivity, which is regulated by the network itself. This is the goal of the present manuscript, i.e., to obtain an upper bound for the conductivity of disordered NT networks.…”

mentioning

confidence: 99%

Upper bound for the conductivity of nanotube networks

Pereira¹,

Rocha²,

Latgé³

et al. 2009

Applied Physics Letters

View full text Add to dashboard Cite

Films composed of nanotube networks have their conductivities regulated by the junction resistances formed between tubes. Conductivity values are enhanced by lower junction resistances but should reach a maximum that is limited by the network morphology. By considering ideal ballistic-like contacts between nanotubes, we use the Kubo formalism to calculate the upper bound for the conductivity of such films and show how it depends on the nanotube concentration as well as on their aspect ratio. Highest measured conductivities reported so far are approaching this limiting value, suggesting that further progress lies with metallic nanowires rather than carbon nanotubes. © 2009 American Institute of Physics. ͓doi:10.1063/1.3236534͔The search for thin films that are flexible, transparent, and conductive is driven by their potential as transparent electrodes. [1][2][3] One common route is to use films made by a disordered network of carbon nanotubes ͑NTs͒. [4][5][6][7][8][9] In this case, electrons move across the entire film by moving between NT in close proximity. The conductivity is limited by the tunneling between tubes, which introduces a significant inter-NT junction resistance. To make the films more conductive, one needs to improve the coupling between NT, which recently has been achieved with acid treatments. 10,11 Further attempts are being made to lower the junction resistance and surpass the best conductivity reported so far, which currently stands at Ϸ 6 ϫ 10 5 S / m. 5,10,11 In addition to the junction resistance, the network morphology also plays a role in limiting the film conductivity. In fact, we have recently demonstrated how sensitive to the network connectivity the conductivity can be. 12 This means that no matter how much progress is made in lowering the junction resistance, there should be a maximum value for the film conductivity, which is regulated by the network itself. This is the goal of the present manuscript, i.e., to obtain an upper bound for the conductivity of disordered NT networks. The knowledge of this upper bound should avoid overoptimistic expectations for the transport properties of the films. Furthermore, understanding the interplay between network morphology and the intrinsic conductances of NT may be explored to deal with films made of other nanowires ͑NWs͒. 13,14 Since we are interested in the best-case scenario in which the electronic conductivity is at its maximum, we must eliminate potential sources of scattering and decoherence such as structural imperfections, impurities, and interaction with other quasiparticles. In this situation, it is appropriate to consider a purely ballistic regime of transport within the NW, which calls for a quantum description of the conductivity. NTs are known to behave as ballistic conductors with two quanta of conductance 15 and are often referred to as possessing two conducting channels. How much interference there is between these channels is what determines how the network affects the film conductivity. Furthermore, because other quantum wir...

show abstract

“…We found one: films of entangled carbon nanotubes. 14,15 These films are currently being investigated for a number of applications 16 due to their, for example, mechanical 17 and electrical 18 properties. We refer to these films as buckypaper.…”

Section: Introductionmentioning

confidence: 99%

Carbon-Nanotube-Based Materials for Protein Crystallization

Asanithi

Saridakis

Govada

et al. 2009

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

We report on the first use of carbon-nanotube based films to produce crystals of proteins. The crystals nucleate on the surface of the film. The difficulty of crystallising proteins is a major bottleneck in the determination of the structure and function of biological molecules. The crystallisation of two model proteins and two medically relevant proteins was studied. Quantitative data on the crystallisation times of the model protein lysozyme are also presented. Two types of the nanotube film, one made with the surfactant Triton X-100 (TX-100) and one with gelatin, were tested. Both induce nucleation of the crystal phase at supersaturations at which the protein solution would otherwise remain clear, however the gelatin-based film induced nucleation down to much lower supersaturations for the two model proteins with which it was used. It appears that the interactions of gelatin with the protein molecules are particularly favourable to nucleation. Crystals of the C1 domain of the human cardiac myosin-binding protein-C that diffracted to a resolution of 1.6Å, were obtained on the TX-100 film. This is far superior to the best crystals obtained using standard techniques, which only diffracted to 3.0 Å. Thus, both our nanotube-based films are very promising candidates for future work on crystallising difficult-tocrystallise target proteins.3

show abstract

The relationship between network morphology and conductivity in nanotube films

Cited by 128 publications

References 30 publications

Electronic transport on carbon nanotube networks: A multiscale computational approach

Electronic transport on carbon nanotube networks: A multiscale computational approach

Upper bound for the conductivity of nanotube networks

Carbon-Nanotube-Based Materials for Protein Crystallization

Contact Info

Product

Resources

About