Surface state transport and ambipolar electric field effect in Bi 2Se3 nanodevices

Hadar Steinberg, Dillon R. Gardner, Young S. Lee, Pablo Jarillo-Herrero*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

273 Scopus citations

Abstract

Electronic transport experiments involving the topologically protected states found at the surface of Bi2Se3 and other topological insulators require fine control over carrier density, which is challenging with existing bulk-doped material. Here we report on electronic transport measurements on thin (<100 nm) Bi2Se3 devices and show that the density of the surface states can be modulated via the electric field effect by using a top-gate with a high-k dielectric insulator. The conductance dependence on geometry, gate voltage, and temperature all indicate that transport is governed by parallel surface and bulk contributions. Moreover, the conductance dependence on top-gate voltage is ambipolar, consistent with tuning between electrons and hole carriers at the surface.

Original languageAmerican English
Pages (from-to)5032-5036
Number of pages5
JournalNano Letters
Volume10
Issue number12
DOIs
StatePublished - 8 Dec 2010

Keywords

  • Topological insulator
  • bismuth selenide
  • exfoliation
  • surface state

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