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# Ambipolar field effect in the ternary topological insulator (BixSb1–x)2Te3 by composition tuning

## Abstract

Topological insulators exhibit a bulk energy gap and spin-polarized surface states that lead to unique electronic properties1,2,3,4,5,6,7,8,9, with potential applications in spintronics and quantum information processing. However, transport measurements have typically been dominated by residual bulk charge carriers originating from crystal defects or environmental doping10,11,12, and these mask the contribution of surface carriers to charge transport in these materials. Controlling bulk carriers in current topological insulator materials, such as the binary sesquichalcogenides Bi2Te3, Sb2Te3 and Bi2Se3, has been explored extensively by means of material doping8,9,11 and electrical gating13,14,15,16, but limited progress has been made to achieve nanostructures with low bulk conductivity for electronic device applications. Here we demonstrate that the ternary sesquichalcogenide (BixSb1–x)2Te3 is a tunable topological insulator system. By tuning the ratio of bismuth to antimony, we are able to reduce the bulk carrier density by over two orders of magnitude, while maintaining the topological insulator properties. As a result, we observe a clear ambipolar gating effect in (BixSb1–x)2Te3 nanoplate field-effect transistor devices, similar to that observed in graphene field-effect transistor devices17. The manipulation of carrier type and density in topological insulator nanostructures demonstrated here paves the way for the implementation of topological insulators in nanoelectronics and spintronics.

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## References

1. Moore, J. E. The birth of topological insulators. Nature 464, 194–198 (2010).

2. Hasan, M. Z. & Kane, C. L. Colloquium: topological insulators. Rev. Mod. Phys. 82, 3045–3067 (2010).

3. Qi, X-L. & Zhang, S-C. Topological insulators and superconductors. Preprint at http://arxiv.org/abs/1008.2026 (2010).

4. Bernevig, B. A., Hughes, T. L. & Zhang, S-C. Quantum spin Hall effect and topological phase transition in HgTe quantum wells. Science 314, 1757–1761 (2006).

5. Konig, M. et al. Quantum spin Hall insulator state in HgTe quantum wells. Science 318, 766–770 (2007).

6. Zhang, H. et al. Topological insulators in Bi2Se3, Bi2Te3 and Sb2Te3 with a single Dirac cone on the surface. Nature Phys. 5, 438–442 (2009).

7. Xia, Y. et al. Observation of a large-gap topological-insulator class with a single Dirac cone on the surface. Nature Phys. 5, 398–402 (2009).

8. Chen, Y. L. et al. Experimental realization of a three-dimensional topological insulator, Bi2Te3 . Science 325, 178–181 (2009).

9. Hsieh, D. et al. A tunable topological insulator in the spin helical Dirac transport regime. Nature 460, 1101–1105 (2009).

10. Analytis, J. G. et al. Bulk Fermi surface coexistence with Dirac surface state in Bi2Se3: a comparison of photoemission and Shubnikov–de Haas measurements. Phys. Rev. B 81, 205407 (2010).

11. Analytis, J. G. et al. Two-dimensional surface state in the quantum limit of a topological insulator. Nature Phys. 6, 960–964 (2010).

12. Kong, D. et al. Rapid surface oxidation as a source of surface degradation factor for Bi2Se3 . ACS Nano 5, 4698–4703 (2011).

13. Chen, J. et al. Gate-voltage control of chemical potential and weak antilocalization in Bi2Se3 . Phys. Rev. Lett. 105, 176602 (2010).

14. Checkelsky, J. G., Hor, Y. S., Cava, R. J. & Ong, N. P. Bulk band gap and surface state conduction observed in voltage-tuned crystals of the topological insulator Bi2Se3 . Phys. Rev. Lett. 106, 196801 (2011).

15. Chen, J. et al. Tunable surface conductivity in Bi2Se3 revealed in diffusive electron transport. Phys. Rev. B 83, 241304 (2011).

16. Steinberg, H., Gardner, D. R., Lee, Y. S. & Jarillo-Herrero, P. Surface state transport and ambipolar electric field effect in Bi2Se3 nanodevices. Nano Lett. 10, 5032–5036 (2010).

17. Novoselov, K. S. et al. Electric field effect in atomically thin carbon films. Science 306, 666–669 (2004).

18. Hsieh, D. et al. Observation of time-reversal-protected single-Dirac-cone topological-insulator states in Bi2Te3 and Sb2Te3 . Phys. Rev. Lett. 103, 146401 (2009).

19. Alpichshev, Z. et al. STM imaging of electronic waves on the surface of Bi2Te3: topologically protected surface states and hexagonal warping effects. Phys. Rev. Lett. 104, 016401 (2010).

20. Zhang, Y. et al. Crossover of the three-dimensional topological insulator Bi2Se3 to the two-dimensional limit. Nature Phys. 6, 584–588 (2010).

21. Peng, H. et al. Aharonov–Bohm interference in topological insulator nanoribbons. Nature Mater. 9, 225–229 (2010).

22. Qu, D-X., Hor, Y. S., Xiong, J., Cava, R. J. & Ong, N. P. Quantum oscillations and Hall anomaly of surface states in the topological insulator Bi2Te3 . Science 329, 821–824 (2010).

23. Xiu, F. et al. Manipulating surface states in topological insulator nanoribbons. Nature Nanotech. 6, 216–221 (2011).

24. Fu, L. Hexagonal warping effects in the surface states of the topological insulator Bi2Te3 . Phys. Rev. Lett. 103, 266801 (2009).

25. Xu, S-Y. et al. Topological phase transition and texture inversion in a tunable topological insulator. Science 332, 560–564 (2011).

26. Kong, D. et al. Few-layer nanoplates of Bi2Se3 and Bi2Te3 with highly tunable chemical potential. Nano Lett. 10, 2245–2250 (2010).

27. Kim, D. et al. Minimum conductivity and charge inhomogeneity in Bi2Se3 in the topological regime. Preprint at http://arxiv.org/abs/1105.1410 (2011).

28. Liu, C-X. et al. Oscillatory crossover from two-dimensional to three-dimensional topological insulators. Phys. Rev. B 81, 041307 (2010).

29. Li, Y. Y. et al. Intrinsic topological insulator Bi2Te3 thin films on Si and their thickness limit. Adv. Mater. 22, 4002–4007 (2010).

30. Cho, S., Butch, N. P., Paglione, J. & Fuhrer, M. S. Insulating behavior in ultrathin bismuth selenide field effect transistors. Nano Lett. 11, 1925–1927 (2011).

31. Zhang, J. et al. Dirac band engineering in (Bi1–xSbx)2Te3 ternary topological insulators. Preprint at http://arxiv.org/abs/1106.1755 (2011).

## Acknowledgements

Y.C. acknowledges support from the Keck Foundation, a DARPA MESO project (no. N66001-11-1-4105) and a King Abdullah University of Science and Technology (KAUST) Investigator Award (no. KUS-l1-001-12). Y.L.C. acknowledges support from a DARPA MESO project (no. N66001-11-1-4105). Z.K.L., Z.X.S., Y.L.C., J.G.A. and I.R.F. acknowledge support from Department of Energy, Office of Basic Energy Science (contract DE-AC02-76SF00515). K.L. acknowledges support from the KAUST Postdoctoral Fellowship (no. KUS-F1-033-02).

## Author information

Authors

### Contributions

D.K., Y.L.C. and Y.C. conceived the experiments. Y.L.C. and Z.K.L. carried out ARPES measurements. J.G.A. synthesized and characterized bulk single crystals. Q.F.Z. performed electronic structure calculations. D.K. and J.J.C. carried out synthesis, structural characterization and device fabrication for nanoplates. D.K., K.L., J.J.C., S.S.H. and K.J.K. carried out transport measurements and analyses. All authors contributed to the scientific planning and discussions.

### Corresponding author

Correspondence to Yi Cui.

## Ethics declarations

### Competing interests

The authors declare no competing financial interests.

## Supplementary information

### Supplementary information

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Reprints and Permissions

Kong, D., Chen, Y., Cha, J. et al. Ambipolar field effect in the ternary topological insulator (BixSb1–x)2Te3 by composition tuning. Nature Nanotech 6, 705–709 (2011). https://doi.org/10.1038/nnano.2011.172

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• DOI: https://doi.org/10.1038/nnano.2011.172

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