You are here : Home > Nano Tech/Components > Materials/Advanced Processes > Nano Objects

Article | Energies | Materials


​Carbon nano-objects: materials with numerous properties for a wide range of applications

Nano Objects

Published on 6 October 2016

Liten’s research on carbon-based materials—graphene and carbon nanotubes—dates back to 2000. Our main focus is on making these materials. We are capable of making 4 nm to 5 nm diameter, 1 mm long nanotubes. Our catalytic process offers the advantage of producing tubes of the same length, diameter, and structure, which can be used for battery electrodes and sensors for microelectronics applications or for electronic circuit interconnects. The nanotubes possess good conductivity, semiconductivity, flexibility, and resistance.

Nano-objects are less expensive and more effective than other materials, providing an affordable, high-performance alternative to techniques currently used in a number of fields.

  • Graphene, a form of graphite forming one-atom-thick planar sheets that are both transparent and electrically conductive, is being investigated for a number of applications. The material’s one-atom-thick, two-dimensional structure ensures very good electron mobility, resulting in excellent electrical conductivity, a crucial factor for many electronics applications. The material could therefore be used to make electrically conductive thin layers, which could eventually replace the indium oxide (a finite resource) used in touch screens and solar cells.
  • Carbon nanotubes—like rolled-up graphene sheets—offer exceptional electrical conductivity or semiconductivity, depending on how the atoms are arranged on the surface. Research is underway on how to use the nanotubes to replace silicon in a new generation of electronic components. Advances in microelectronics over the past few decades have focused on making transistors smaller—creating new technological challenges. One possible way around the issues inherent to miniaturization is to come up with a “third dimension.” This will require making 3D connected transistors, something that cannot be achieved with silicon-based technologies—but that is possible with graphene and carbon nanotubes.


Liten has developed nanotubes for lithium-sulfur batteries developed in our labs. These materials, which take the form of a “carpet” of nanotubes, are highly porous: the nanotubes grow perpendicular to surfaces to form electrodes into which sulfur is inserted and desorbed in a reversible manner, without damaging the structures. The nanotubes can be used to make batteries with storage capacities well above those of current solutions. For instance, where a lithium-ion battery would have a theoretical capacity of 450 mAh/g, a lithium-sulfur battery would offer 1,600 mAh/g.

We are now working on making conductive wires from carbon nanotubes. The wires would be used to make macroscopic conductors offering high electrical conductivity while remaining very light in weight. The wires could be useful in aircraft cabling systems, where they would substantially reduce weight and, therefore, fuel consumption. And, with rising copper and aluminum prices, carbon-based conductors offer an obvious economic advantage.

Nanotubes can also be used to give non-conducting materials like polymers conducting capacities with much smaller amounts of carbon black, which offers the advantage of not deteriorating the polymers’ original properties. Furthermore, nanotubes offer anticorrosion properties that can increase materials’ durability. Finally, nanotubes can help make flexible, yet very resistant materials (ten times stronger than steel) with excellent thermal conductivity.

Liten brings know-how from a broad range of fields to this research, with expertise in physical chemistry (nanotube growth), processes for integrating nano-objects into components (etching), and characterization (electrical, Raman). We also use the CEA nanocharacterization platform to gain an in-depth understanding of these materials.

BENEFITS

Enhanced technical and economic performance for the materials of the future

  • The use of nanomaterials will pave the way for new applications in energy, electronics, and microelectronics.
  • Because Liten is capable of making nanotubes with a diverse range of structures, we can give materials new properties, either by adding nanotubes or by replacing an existing material with nanotubes.
  • Nanotubes and nanotube-based conductors are a source of energy savings with the potential to overcome the technical hurdles inherent to the miniaturization of electrical circuits and replace rare, expensive metals.

PROJECTS

Liten is working with Intel on interconnects. The goal of this joint research program is to find a replacement for copper, which, given the miniaturization of microelectronic components, presents reliability and performance issues. Miniaturization results in higher current densities in the circuits, which in turn causes reduced conductivity and reliability due to electromigration in the copper interconnects. Carbon nanotubes, on the other hand, can withstand far higher current densities (around 1,000 times higher than equivalent copper systems). This early-stage research is still a long way away from addressing specific applications.

Liten is also engaged in several EU research programs:

  • Grafol: Large-scale R2R (roll-to-roll) graphene production, a mass-production technique that can handle large surface areas of flexible materials.
  • Gladiator FP7 NMP: This project is focusing on ways to produce larger graphene sheets of higher quality using high-temperature catalytic decomposition of a carbon gas (CVD); the goal is to reduce manufacturing costs to make integrating the material into electronic components a more attractive alternative.
  • Connect, a Horizon 2020 program: The purpose of this program is to make copper-nanotube composites for microelectronic circuits; recent results have demonstrated that, with the right composite, it is possible to obtain the conductivity of copper while substantially increasing current capacity, potentially pushing back the limits of electromigration by a factor of 100.

FACTS & FIGURES

  • ​4 employees
  • More than ten patents


Publications:

Joyeux X, Ammar S, Dijon J, Pinson J. 2010. September 2010. Growth of carbon nanotubes through selective deposition of nanoparticles. Journal of Materials Chemistry 20: 7197–7200.

Dijon J. 2013. Horizontal carbon nanotube interconnects for advanced integrated circuits. 2013. MRS spring meeting. Mater. Res. Soc. Symp. Proc. Vol. 1559.

Kim H, Renault O, Tyurnina A, Simonato JP, Rouchon D, Mariolle D, Chevalier N, Dijon J. July 2014. Doping efficiency of single and randomly stacked bilayer graphene by iodine adsorption. Applied Physics Letters 105: 011605.

Guerin H, Le Poche H,  Pohled R, Buitrago E, Fernández-Bolaños Badíaa M, Dijon J, Ionescu A. February 2015. Carbon nanotube gas sensor array for multiplex analytediscrimination. Sensors and Actuators B 207(A): 833–842.

Liatard S, Benhamouda K, Fournier A, Ramos R, Barchasz C, Dijon J. April 2015. Vertically-aligned carbon nanotubes on aluminium as a light-weight positive electrode for lithium-polysulfide batteries. Chemical Communications 51: 7749–7752.

Arun A, Le Poche H, Idda T, Acquaviva D, Fernández-Bolaños Badíaa M, Pantigny P, Salet P, Ionescu A. 2011. Tunable MEMS capacitors using vertical carbon nanotubes arrays grown on metal lines. Nanotechnology 22(2): 1–9.


Contact an expert to find out more

Facts & Figures