Top gating of epitaxial (Bi_{1-x}Sb_x)2Te3 topological insulator thin films

Abstract

The tunability of the chemical potential for a wide range encompassing the Dirac point is important for many future devices based on topological insulators. Here we report a method to fabricate highly efficient top gates on epitaxially grown (Bi_{1-x}Sb_x)2Te3 topological insulator thin films without degrading the film quality. By combining an in situ deposited Al2O3 capping layer and a SiN_x dielectric layer deposited at low temperature, we were able to protect the films from degradation during the fabrication processes. We demonstrate that by using this top gate, the carriers in the top surface can be efficiently tuned from n- to p-type. We also show that magnetotransport properties give evidence for decoupled transport through top and bottom surfaces for the entire range of gate voltage, which is only possible in truly bulk-insulating samples.

arXiv comment5 pages, 3 figures; accepted for publication in Appl. Phys. Lett

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Cited by in corpus (19)

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• Large linear magnetoresistance in the Dirac semimetal TlBiSSe
• Electrical control of magnetism by electric field and current-induced torques
• Opportunities in topological insulator devices
• Large anomalous Hall effect in ferromagnetic insulator-topological insulator heterostructures
• Switching of Charge-Current-Induced Spin Polarization in the Topological Insulator BiSbTeSe2
• Weak antilocalization and electron-electron interaction in coupled multiple-channel transport in a Bi${}_2$Se${}_3$ thin film
• In-situ spectroscopy of intrinsic Bi2Te3 topological insulator thin films and impact of extrinsic defects
• Gate-tunable transport properties of in-situ capped Bi${}_2$Te${}_3$ topological insulator thin films
• Quantum Transport and Potential of Topological States for Thermoelectricity in Bi${}_2$Te${}_3$ Thin Films
• Top-down fabrication of bulk-insulating topological insulator nanowires for quantum devices
• Observability of surface Andreev bound states in a topological insulator in proximity to an s-wave superconductor
• Weak Antilocalization and Universal Conductance Fluctuations in Bismuth Telluro-Sulfide Topological Insulators
• Topological insulator spin transistor
• Electrostatic Modulation of the Electronic Properties of Dirac Semimetal Na3Bi
• Robust Gapless Surface State against Surface Magnetic Impurities on (Bi${}_{0.5}$Sb${}_{0.5}$)${}_2$Te${}_3$ Evidenced by In Situ Magnetotransport Measurements
• Characterizing the chemical potential disorder in the topological insulator (Bi${}_{1-x}$Sb${}_x$)${}_2$Te${}_3$ thin films
• Relaxation dynamics of the optically driven nonequilibrium states in the electron- and hole-doped topological-insulator materials $(B{i}_{1-x}S{b}_x{)}_{2}T{e}_3$
• From classical to quantum regime of topological surface states via defect engineering