Solution to the Hole-Doping Problem and Tunable Quantum Hall Effect in Bi2Se3 Thin Films

Jisoo Moon, Nikesh Koirala, Maryam Salehi, Wenhan Zhang, Weida Wu, Seongshik Oh

Research output: Contribution to journalArticlepeer-review

20 Scopus citations

Abstract

Bi2Se3, one of the most widely studied topological insulators (TIs), is naturally electron-doped due to n-type native defects. However, many years of efforts to achieve p-type Bi2Se3 thin films have failed so far. Here, we provide a solution to this long-standing problem, showing that the main culprit has been the high density of interfacial defects. By suppressing these defects through an interfacial engineering scheme, we have successfully implemented p-type Bi2Se3 thin films down to the thinnest topological regime. On this platform, we present the first tunable quantum Hall effect (QHE) study in Bi2Se3 thin films and reveal not only significantly asymmetric QHE signatures across the Dirac point but also the presence of competing anomalous states near the zeroth Landau level. The availability of doping tunable Bi2Se3 thin films will now make it possible to implement various topological quantum devices, previously inaccessible.

Original languageEnglish (US)
Pages (from-to)820-826
Number of pages7
JournalNano Letters
Volume18
Issue number2
DOIs
StatePublished - Feb 14 2018

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

Keywords

  • BiSe
  • Topological insulator
  • doping
  • interface
  • quantum Hall effect

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