Fermi-level tuning of the Dirac surface state in (Bi1-xSbx)2Se3 thin films

Yosuke Satake, Junichi Shiogai, Daichi Takane, Keiko Yamada, Kohei Fujiwara, Seigo Souma, Takafumi Sato, Takashi Takahashi, Atsushi Tsukazaki

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13 Citations (Scopus)


We report on the electronic states and the transport properties of three-dimensional topological insulator (Bi1-xSbx)2Se3 ternary alloy thin films grown on an isostructural Bi2Se3 buffer layer on InP substrates. By angle-resolved photoemission spectroscopy, we clearly detected Dirac surface states with a large bulk band gap of 0.2-0.3 eV in the (Bi1-xSbx)2Se3 film with x = 0.70. In addition, we observed by Hall effect measurements that the dominant charge carrier converts from electron (n-type) to hole (p-type) at around x = 0.7, indicating that the Fermi level can be controlled across the Dirac point. Indeed, the carrier transport was shown to be governed by Dirac surface state in 0.63 x 0.75. These features suggest that Fermi-level tunable (Bi1-xSbx)2Se3-based heterostructures provide a platform for extracting exotic topological phenomena.

Original languageEnglish
Article number085501
JournalJournal of Physics Condensed Matter
Issue number8
Publication statusPublished - 2018 Feb 1


  • angle-resolved photoemission spectroscopy
  • bismuth selenide
  • Dirac surface state
  • electrical transoport
  • molecular beam epitaxy
  • topological insulator


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