Band gap narrowing and electron doping by potassium encapsulation into single-walled carbon nanotubes

Hideyuki Maki, Satoru Suzuki, Tetsuya Sato, Koji Ishibashi

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

We have fabricated field-effect transistors (FETs) with pristine and potassium-encapsulated single-walled carbon nanotube (SWNT) films, and the effects of potassium encapsulation are investigated. The transformation from a unipolar characteristic to an ambipolar characteristic by potassium encapsulation is observed from the measurement of the gate voltage dependence (Vgs) of the current (I) for SWNT-film FETs. This result indicates that the potassium encapsulation into SWNTs causes band gap narrowing. In addition, the n-type region of the I-Vgs, curve is expanded during annealing of the devices; electron transfer from potassium to SWNTs occurs owing to the removal of the adsorbates. The adsorbate removal is confirmed by photoemission spectroscopy measurement. The FET with an individual potassium-encapsulated SWNT shows an ambipolar characteristic.

Original languageEnglish
Pages (from-to)2486-2489
Number of pages4
JournalJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
Volume46
Issue number4 B
DOIs
Publication statusPublished - 2007 Apr 24

Fingerprint

Single-walled carbon nanotubes (SWCN)
Encapsulation
Potassium
potassium
Energy gap
carbon nanotubes
Doping (additives)
Electrons
Field effect transistors
electrons
field effect transistors
Adsorbates
Photoelectron spectroscopy
electron transfer
photoelectric emission
Annealing
annealing
causes
Electric potential
electric potential

Keywords

  • Ambipolar transport
  • Band gap
  • Carbon nanotube
  • Electron doping
  • Field-effect transistor
  • Film
  • Potassium
  • Work function

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this

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title = "Band gap narrowing and electron doping by potassium encapsulation into single-walled carbon nanotubes",
abstract = "We have fabricated field-effect transistors (FETs) with pristine and potassium-encapsulated single-walled carbon nanotube (SWNT) films, and the effects of potassium encapsulation are investigated. The transformation from a unipolar characteristic to an ambipolar characteristic by potassium encapsulation is observed from the measurement of the gate voltage dependence (Vgs) of the current (I) for SWNT-film FETs. This result indicates that the potassium encapsulation into SWNTs causes band gap narrowing. In addition, the n-type region of the I-Vgs, curve is expanded during annealing of the devices; electron transfer from potassium to SWNTs occurs owing to the removal of the adsorbates. The adsorbate removal is confirmed by photoemission spectroscopy measurement. The FET with an individual potassium-encapsulated SWNT shows an ambipolar characteristic.",
keywords = "Ambipolar transport, Band gap, Carbon nanotube, Electron doping, Field-effect transistor, Film, Potassium, Work function",
author = "Hideyuki Maki and Satoru Suzuki and Tetsuya Sato and Koji Ishibashi",
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T1 - Band gap narrowing and electron doping by potassium encapsulation into single-walled carbon nanotubes

AU - Maki, Hideyuki

AU - Suzuki, Satoru

AU - Sato, Tetsuya

AU - Ishibashi, Koji

PY - 2007/4/24

Y1 - 2007/4/24

N2 - We have fabricated field-effect transistors (FETs) with pristine and potassium-encapsulated single-walled carbon nanotube (SWNT) films, and the effects of potassium encapsulation are investigated. The transformation from a unipolar characteristic to an ambipolar characteristic by potassium encapsulation is observed from the measurement of the gate voltage dependence (Vgs) of the current (I) for SWNT-film FETs. This result indicates that the potassium encapsulation into SWNTs causes band gap narrowing. In addition, the n-type region of the I-Vgs, curve is expanded during annealing of the devices; electron transfer from potassium to SWNTs occurs owing to the removal of the adsorbates. The adsorbate removal is confirmed by photoemission spectroscopy measurement. The FET with an individual potassium-encapsulated SWNT shows an ambipolar characteristic.

AB - We have fabricated field-effect transistors (FETs) with pristine and potassium-encapsulated single-walled carbon nanotube (SWNT) films, and the effects of potassium encapsulation are investigated. The transformation from a unipolar characteristic to an ambipolar characteristic by potassium encapsulation is observed from the measurement of the gate voltage dependence (Vgs) of the current (I) for SWNT-film FETs. This result indicates that the potassium encapsulation into SWNTs causes band gap narrowing. In addition, the n-type region of the I-Vgs, curve is expanded during annealing of the devices; electron transfer from potassium to SWNTs occurs owing to the removal of the adsorbates. The adsorbate removal is confirmed by photoemission spectroscopy measurement. The FET with an individual potassium-encapsulated SWNT shows an ambipolar characteristic.

KW - Ambipolar transport

KW - Band gap

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KW - Field-effect transistor

KW - Film

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