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

Journal Article · Sun Feb 07 00:00:00 EST 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4941018· OSTI ID:22494985

Tung, Y.; Chiang, Y. F.; Deng, Z. X.; Chen, Y. C. ^[1]; Huang, J. C. A., ^[1]; Pi, T. -W.; Tsuei, K. -D. ^[2]; Li, Z.; Qiu, H. ^[3]

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1. Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan (China)
2. National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan (China)
3. School of Electronic Science and Applied Physics, HeFei University of Technology, Anhui (China)

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.

• OSTI ID: 22494985
• Journal Information: Journal of Applied Physics, Vol. 119, Issue 5; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

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