Charged iodide in chains behind the highly efficient iodine doping in carbon nanotubes

Ahmed Zubair (1) , Damien Tristant (2, 3) , Chunyang Nie (4, 3) , Dmitri Tsentalovich (1) , Robert Headrick (1) , Matteo Pasquali (1) , Junichiro Kono (1) , Vincent Meunier (5) , Emmanuel Flahaut (4) , Marc Monthioux (3) , I.C. Gerber (2) , Pascal Puech (3)

1 Rice University [Houston]
2 LPCNO - Laboratoire de physique et chimie des nano-objets
3 CEMES-M3 - Matériaux Multi-fonctionnels et Multi-échelles
4 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
5 RPI - Rensselaer Polytechnic Institute

The origin of highly efficient iodine doping of carbon nanotubes is not well understood. Relying on firstprinciples calculations, we found that iodine molecules (I2) in contact with a carbon nanotube interact to form monoiodide or/and polyiodide from two and three I2 as a result of removing electrons from the carbon nanotube (p-type doping). Charge per iodine atom for monoiodide ion or iodine atom at end of iodine chain is significantly higher than that for I2. This atomic analysis extends previous studies showing that polyiodide ions are the dominant dopants. Moreover, we observed isolated I atoms in atomically resolved transmission electron microscopy, which proves the production of monoiodide. Finally, using Raman spectroscopy, we quantitatively determined the doping level and estimated the number of conducting channels in high electrical conductivity fibers composed of iodine-doped double-wall carbon nanotubes.

Mots clés: Carbon nanotubes; Doping; Iodine; Charge transfer; Raman spectroscopy

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Physique mathématique [math-ph]; Matériaux

Ahmed Zubair, Damien Tristant, Chunyang Nie, Dmitri Tsentalovich, Robert Headrick, et al.. Charged iodide in chains behind the highly efficient iodine doping in carbon nanotubes. Physical Review Materials, 2017, 1 (6), pp.064002. ⟨10.1103/PhysRevMaterials.1.064002⟩. ⟨hal-01867475⟩