title: Stable and controlled amphoteric doping by encapsulation of organic molecules inside carbon nanotubes.
abstract: Single-walled carbon nanotubes (SWNTs) have strong potential for molecular electronics, owing to their unique structural and electronic properties. However, various outstanding issues still need to be resolved before SWNT-based devices can be made. In particular, large-scale, air-stable and controlled doping is highly desirable. Here we present a method for integrating organic molecules into SWNTs that promises to push the performance limit of these materials for molecular electronics. Reaction of SWNTs with molecules having large electron affinity and small ionization energy achieved p- and n-type doping, respectively. Optical characterization revealed that charge transfer between SWNTs and molecules starts at certain critical energies. X-ray diffraction experiments revealed that molecules are predominantly encapsulated inside SWNTs, resulting in an improved stability in air. The simplicity of the synthetic process offers a viable route for the large-scale production of SWNTs with controlled doping states.
authors.affiliation: Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan. takenobu@imr.edu
authors.forename: Taishi
authors.initials: T
authors.lastname: Takenobu
authors.forename: Takumi
authors.initials: T
authors.lastname: Takano
authors.forename: Masashi
authors.initials: M
authors.lastname: Shiraishi
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Murakami
authors.forename: Masafumi
authors.initials: M
authors.lastname: Ata
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Kataura
authors.forename: Yohji
authors.initials: Y
authors.lastname: Achiba
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Iwasa
mesh_terms: D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis* / Q000737:chemistry; D003460:Crystallization / Q000379:methods*; D003461:Crystallography / Q000379:methods*; D004867:Equipment Design; D006863:Hydrogen-Ion Concentration; D046911:Macromolecular Substances; D008422:Materials Testing; D008968:Molecular Conformation; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009930:Organic Chemicals / Q000138:chemical synthesis / Q000737:chemistry*; D012666:Semiconductors
chemical_list: D020099:Coated Materials, Biocompatible; D046911:Macromolecular Substances; D037742:Nanotubes, Carbon; D009930:Organic Chemicals