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Growth of Topological Insulator Bi 2 Se 3 Thin Films on SrTiO 3 with Large Tunability in Chemical Potential
Author(s) -
Zhang Guanhua,
Qin Huajun,
Chen Jun,
He Xiaoyue,
Lu Li,
Li Yongqing,
Wu Kehui
Publication year - 2011
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201002667
Subject(s) - materials science , topological insulator , thin film , molecular beam epitaxy , fabrication , hall effect , dielectric , substrate (aquarium) , electrical resistivity and conductivity , optoelectronics , insulator (electricity) , epitaxy , condensed matter physics , nanotechnology , electrical engineering , medicine , oceanography , physics , alternative medicine , engineering , layer (electronics) , pathology , geology
The growth of high quality, gate‐tunable topological insulator Bi 2 Se 3 thin films on SrTiO 3 substrates by molecular beam epitaxy is reported in this paper. The optimized substrate preparation procedures are critical for obtaining undoped Bi 2 Se 3 thin films with sufficiently low carrier densities while maintaining the strong dielectric strength of the substrates. The large tunability in chemical potential is manifested in the greatly enhanced longitudinal resistivity and the reversal of the sign of the Hall resistivity at negative back‐gate voltages. These thin films provide a convenient basis for fabrication of hybrid devices consisting of gate‐tunable topological insulators and other materials such as a superconductor and a ferromagnet.