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Title: Growth and characterization of molecular beam epitaxy-grown Bi{sub 2}Te{sub 3−x}Se{sub x} topological insulator alloys

We report a systematic study on the structural and electronic properties of Bi{sub 2}Te{sub 3−x}Se{sub x} topological insulator alloy grown by molecular beam epitaxy (MBE). A mixing ratio of Bi{sub 2}Se{sub 3} to Bi{sub 2}Te{sub 3} was controlled by varying the Bi:Te:Se flux ratio. X-ray diffraction and Raman spectroscopy measurements indicate the high crystalline quality for the as-grown Bi{sub 2}Te{sub 3−x}Se{sub x} films. Substitution of Te by Se is also revealed from both analyses. The surfaces of the films exhibit terrace-like quintuple layers and their size of the characteristic triangular terraces decreases monotonically with increasing Se content. However, the triangular terrace structure gradually recovers as the Se content further increases. Most importantly, the angle-resolved photoemission spectroscopy results provide evidence of single-Dirac-cone like surface states in which Bi{sub 2}Te{sub 3−x}Se{sub x} with Se/Te-substitution leads to tunable surface states. Our results demonstrate that by fine-tuned MBE growth conditions, Bi{sub 2}Te{sub 3−x}Se{sub x} thin film alloys with tunable topological surface states can be obtained, providing an excellent platform for exploring the novel device applications based on this compound.
Authors:
; ; ; ;  [1] ;  [1] ;  [2] ;  [3] ; ; ;  [4] ; ;  [5]
  1. Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan (China)
  2. (AOTC), National Cheng Kung University, Tainan 70101, Taiwan (China)
  3. (TCECM), Ministry of Science and Technology, Taipei 10622, Taiwan (China)
  4. National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan (China)
  5. School of Electronic Science and Applied Physics, HeFei University of Technology, Anhui (China)
Publication Date:
OSTI Identifier:
22494985
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 119; Journal Issue: 5; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALLOYS; BISMUTH SELENIDES; BISMUTH TELLURIDES; MOLECULAR BEAM EPITAXY; PHOTOELECTRON SPECTROSCOPY; RAMAN SPECTROSCOPY; SURFACES; THIN FILMS; TOPOLOGY; X-RAY DIFFRACTION