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

Ahmed Zubair, Damien Tristant, Chunyang Nie, Dmitri E. Tsentalovich, Robert J. Headrick, Matteo Pasquali, Junichiro Kono, Vincent Meunier, Emmanuel Flahaut, Marc Monthioux, Iann C. Gerber, and Pascal Puech

Phys. Rev. Materials 1, 064002 – Published 27 November 2017

Abstract

The origin of highly efficient iodine doping of carbon nanotubes is not well understood. Relying on first-principles calculations, we found that iodine molecules $(I_{2})$ in contact with a carbon nanotube interact to form monoiodide or/and polyiodide from two and three $I_{2}$ 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 $I_{2}$ . 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.

Received 26 September 2017

DOI:https://doi.org/10.1103/PhysRevMaterials.1.064002

Physics Subject Headings (PhySH)

Chemical bonding Dopants Electrical conductivity Optical phonons Physisorption

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Ahmed Zubair¹, Damien Tristant^2,3,4, Chunyang Nie^3,5, Dmitri E. Tsentalovich⁶, Robert J. Headrick^6,7, Matteo Pasquali^6,7,8, Junichiro Kono^1,8,9, Vincent Meunier², Emmanuel Flahaut¹⁰, Marc Monthioux³, Iann C. Gerber⁴, and Pascal Puech^3,*

¹Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, USA
²Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
³CEMES-CNRS, UPR-8011, Université Fédérale de Toulouse-Midi-Pyrénées, Toulouse, France
⁴LPCNO, UMR-5215 CNRS, INSA, Université Fédérale de Toulouse-Midi-Pyrénées, Toulouse, France
⁵School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, P. R. China
⁶Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, USA
⁷Department of Chemistry, Rice University, Houston, Texas 77005, USA
⁸Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA
⁹Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
¹⁰Institut Carnot CIRIMAT, Université Fédérale de Toulouse-Midi-Pyrénées, UMR CNRS 5085, Toulouse, France