Charge transfer at junctions of a single layer of graphene and a metallic single walled carbon nanotube

Geraldine L.C. Paulus, Qing Hua Wang, Zachary W. Ulissi, Thomas P. McNicholas, Aravind Vijayaraghavan, Chih Jen Shih, Zhong Jin, Michael S. Strano

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

Junctions between a single walled carbon nanotube (SWNT) and a monolayer of graphene are fabricated and studied for the first time. A single layer graphene (SLG) sheet grown by chemical vapor deposition (CVD) is transferred onto a SiO2/Si wafer with aligned CVD-grown SWNTs. Raman spectroscopy is used to identify metallic-SWNT/SLG junctions, and a method for spectroscopic deconvolution of the overlapping G peaks of the SWNT and the SLG is reported, making use of the polarization dependence of the SWNT. A comparison of the Raman peak positions and intensities of the individual SWNT and graphene to those of the SWNT-graphene junction indicates an electron transfer of 1.12 × 1013 cm-2 from the SWNT to the graphene. This direction of charge transfer is in agreement with the work functions of the SWNT and graphene. The compression of the SWNT by the graphene increases the broadening of the radial breathing mode (RBM) peak from 3.6 ± 0.3 to 4.6 ± 0.5 cm-1 and of the G peak from 13 ± 1 to 18 ± 1 cm-1, in reasonable agreement with molecular dynamics simulations. However, the RBM and G peak position shifts are primarily due to charge transfer with minimal contributions from strain. With this method, the ability to dope graphene with nanometer resolution is demonstrated.

Original languageEnglish (US)
Pages (from-to)1954-1963
Number of pages10
JournalSmall
Volume9
Issue number11
DOIs
StatePublished - Jun 10 2013
Externally publishedYes

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Keywords

  • MD simulations
  • Raman spectroscopy
  • SWNTs
  • charge transfer
  • graphene

ASJC Scopus subject areas

  • Biotechnology
  • Biomaterials
  • Chemistry(all)
  • Materials Science(all)

Cite this

Paulus, G. L. C., Wang, Q. H., Ulissi, Z. W., McNicholas, T. P., Vijayaraghavan, A., Shih, C. J., Jin, Z., & Strano, M. S. (2013). Charge transfer at junctions of a single layer of graphene and a metallic single walled carbon nanotube. Small, 9(11), 1954-1963. https://doi.org/10.1002/smll.201201034