Effect of top dielectric medium on gate capacitance of graphene field effect transistors: Implications in mobility measurements and sensor applications

J. L. Xia, F. Chen, Peter Wiktor, D. K. Ferry, Nongjian Tao

Research output: Contribution to journalArticlepeer-review

67 Scopus citations

Abstract

We have carried out Hall measurement on back-gated graphene field effect transistors (FET) with and without a top dielectric medium. The gate efficiency increases by up to 2 orders of magnitude in the presence of a high κ top dielectric medium, but the mobility does not change significantly. Our measurement further shows that the back-gate capacitance is enhanced dramatically by the top dielectric medium, and the enhancement increases with the size of the top dielectric medium. Our work strongly suggests that the previously reported top dielectric medium-induced charge transport properties of graphene FETs are possibly due to the increase of gate capacitance, rather than enhancement of carrier mobility.

Original languageEnglish (US)
Pages (from-to)5060-5064
Number of pages5
JournalNano Letters
Volume10
Issue number12
DOIs
StatePublished - Dec 8 2010

Keywords

  • Graphene
  • dielectric screening
  • electron transport
  • gate capacitance
  • mobility

ASJC Scopus subject areas

  • Bioengineering
  • General Chemistry
  • General Materials Science
  • Condensed Matter Physics
  • Mechanical Engineering

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