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Selected Topics in Applied Physics
Fermi-Level Tuning of Topological Insulator Thin Films
1Department of Physics, University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
2UVSOR Facility, Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan
(Received April 24, 2013; revised June 15, 2013; accepted July 17, 2013; published online October 16, 2013)
Topological insulators are insulating materials but have metallic edge states with peculiar properties. They are considered to be promising for the development of future low energy consumption nano-electronic devices. However, there is a major problem: Naturally grown materials are not truly insulating owing to defects in their crystal structure. In the present study, we have examined the electronic structure and transport properties of topological insulator ultrathin Bi2Te3 films by angle-resolved photoemission spectroscopy and in situ transport measurements. To realize a truly bulk insulating film, we tried to tune the Fermi-level position using two methods. The first of these, i.e., changing the Si substrate temperature during film growth (350–450 K) to reduce the defects in the grown films, had some effect in reducing the bulk residual carriers, but we could not fabricate a film that showed only the surface states crossing the Fermi level. The second method we employed was to incorporate Pb atoms during film growth since Pb has one less electron than Bi. When the films were grown at around 350 K, we observed a systematic shift in the Fermi level and obtained a bulk insulating film, although it was not possible to move the Dirac point just at the Fermi level. The change in the measured film conductivity was consistent with the shift in the Fermi level and suggested the detection of the surface-state conductivity. For films grown at a higher substrate temperature (450 K), the Fermi level could be tuned only slightly and a bulk n-type film was obtained. Pb incorporation changes the shape of the Dirac cone, suggesting the formation of a stoichiometric ternary alloy of Bi, Pb, and Te, which is another topological insulator.
- C. L. Kane and E. J. Mele:
Phys. Rev. Lett. 95 (2005) 146802[APS].
- D. Hsieh, Y. Xia, D. Qian, L. Wray, J. H. Dil, F. Meier, J. Osterwalder, L. Patthey, J. G. Checkelsky, N. P. Ong, A. V. Fedorov, H. Lin, A. Bansil, D. Grauer, Y. S. Hor, R. J. Cava, and M. Z. Hasan:
Nature 460 (2009) 1101[CrossRef].
- A. Nishide, A. A. Taskin, Y. Takeichi, T. Okuda, A. Kakizaki, T. Hirahara, K. Nakatsuji, F. Komori, Y. Ando, and I. Matsuda:
Phys. Rev. B 81 (2010) 041309[APS](R).
- K. Miyamoto, A. Kimura, T. Okuda, H. Miyahara, K. Kuroda, H. Namatame, M. Taniguchi, S. V. Eremeev, T. V. Menshchikova, E. V. Chulkov, K. Kokh, and O. Tereshchenko:
Phys. Rev. Lett. 109 (2012) 166802[APS].
- S. Souma, M. Komatsu, M. Nomura, T. Sato, A. Takayama, T. Takahashi, K. Eto, K. Segawa, and Y. Ando:
Phys. Rev. Lett. 109 (2012) 186804[APS].
- T. Misawa, T. Yokoyama, and S. Murakami:
Phys. Rev. B 84 (2011) 165407[APS].
- R. Yu, W. Zhang, H. J. Zhang, S. C. Zhang, X. Dai, and Z. Fang: Science 329 (2010) 61.
- L. Fu and C. L. Kane:
Phys. Rev. Lett. 100 (2008) 096407[APS].
- C. W. J. Beenakker: Annu. Rev. Condens. Matter Phys. 4 (2013) 113.
- O. A. Tretiakov, Ar. Abanov, and J. Sinova:
Appl. Phys. Lett. 99 (2011) 113110[AIP Scitation].
- Y. L. Chen, J. G. Analytis, J.-H. Chu, Z. K. Liu, S.-K. Mo, X. L. Qi, H. J. Zhang, D. H. Lu, X. Dai, Z. Fang, S. C. Zhang, I. R. Fisher, Z. Hussain, and Z.-X. Shen: Science 325 (2009) 178.
- Y. S. Hor, J. G. Checkelsky, D. Qu, N. P. Ong, and R. J. Cava:
- A. A. Taskin, Z. Ren, S. Sasaki, K. Segawa, and Y. Ando:
Phys. Rev. Lett. 107 (2011) 016801[APS].
- Z. Ren, A. A. Taskin, S. Sasaki, K. Segawa, and Y. Ando:
Phys. Rev. B 85 (2012) 155301[APS].
- H. Bando, K. Koizumi, Y. Oikawa, K. Daikohara, V. A. Kulbachinskii, and H. Ozaki:
J. Phys.: Condens. Matter 12 (2000) 5607[IoP STACKS].
- J. G. Analytis, R. D. McDonald, S. C. Riggs, J. Chu, G. S. Boebinger, and I. R. Fisher:
Nat. Phys. 6 (2010) 960[CrossRef].
- T. Tanikawa, I. Matsuda, R. Hobara, and S. Hasegawa: e-J. Surf. Sci. Nanotechnol. 1 (2003) 50.
- M. Yamada, T. Hirahara, R. Hobara, S. Hasegawa, H. Mizuno, Y. Miyatake, and T. Nagamura: e-J. Surf. Sci. Nanotechnol. 10 (2012) 400.
- Y. Sakamoto, T. Hirahara, H. Miyazaki, S. Kimura, and S. Hasegawa:
Phys. Rev. B 81 (2010) 165432[APS].
- Y.-Y. Li, G. Wang, X.-G. Zhu, M.-H. Liu, C. Ye, X. Chen, Y.-Y. Wang, K. He, L.-L. Wang, X.-C. Ma, H.-J. Zhang, X. Dai, Z. Fang, X.-C. Xie, Y. Liu, X.-L. Qi, J.-F. Jia, S.-C. Zhang, and Q.-K. Xue:
Adv. Mater. 22 (2010) 4002[CrossRef].
- T. Zhang, P. Cheng, X. Chen, J. Jia, X. Ma, K. He, L. Wang, H. Zhang, X. Dai, Z. Fang, X. Xie, and Q. Xue:
Phys. Rev. Lett. 103 (2009) 266803[APS].
- T. Hirahara, G. Bihlmayer, Y. Sakamoto, M. Yamada, H. Miyazaki, S.-I. Kimura, S. Blügel, and S. Hasegawa:
Phys. Rev. Lett. 107 (2011) 166801[APS].
- M. D'angelo, K. Takase, N. Miyata, T. Hirahara, S. Hasegawa, A. Nishide, M. Ogawa, and I. Matsuda:
Phys. Rev. B 79 (2009) 035318[APS].
- K. Park, J. Heremans, V. Scarola, and D. Minic:
Phys. Rev. Lett. 105 (2010) 186801[APS].
- G. Wang, X. Zhu, Y. Sun, Y. Li, T. Zhang, J. Wen, X. Chen, K. He, L. Wang, X. Ma, J. Jia, S. B. Zhang, and Q. Xue:
Adv. Mater. 23 (2011) 2929[CrossRef].
- We should note that the substrate temperature shown in the present study is lower than that reported in Ref. . This is probably due to the difference in the estimation. In Ref. , it is most likely that a optical pyrometer is used. However, since we did not have such instrument to measure low temperature, we extrapolated the current–temperature curve obtained for the data points above 800 K. In this estimation, 350–450 K was the only temperature range that we could fabricate a Bi2Te3 thin film.
- T. Plechäček, P. Lošt'ák, J. Navrátil, and T. Černohorský: Cryst. Res. Technol. 33 (1998) 911.
- H. Jin, J.-H. Song, A. J. Freeman, and M. G. Kanatzidis:
Phys. Rev. B 83 (2011) 041202[APS].
- S. V. Eremeev, G. Landolt, T. V. Menshchikova, B. Slomski, Y. M. Koroteev, Z. S. Aliev, M. B. Babanly, J. Henk, A. Ernst, L. Patthey, A. Eich, A. A. Khajetoorians, J. Hagemeister, O. Pietzsch, J. Wiebe, R. Wiesendanger, P. M. Echenique, S. T. Tsirkin, I. R. Amiraslanov, J. H. Dil, and E. V. Chulkov:
Nat. Commun. 3 (2012) 635[CrossRef].
- S. Souma, K. Eto, M. Nomura, K. Nakayama, T. Sato, T. Takahashi, K. Segawa, and Y. Ando:
Phys. Rev. Lett. 108 (2012) 116801[APS].
- K. Kuroda, H. Miyahara, M. Ye, S. V. Eremeev, Yu. M. Koroteev, E. E. Krasovskii, E. V. Chulkov, S. Hiramoto, C. Moriyoshi, Y. Kuroiwa, K. Miyamoto, T. Okuda, M. Arita, K. Shimada, H. Namatame, M. Taniguchi, Y. Ueda, and A. Kimura:
Phys. Rev. Lett. 108 (2012) 206803[APS].