Growth of High-Mobility Bi2Te2Se Nanoplatelets on hBN Sheets by van der Waals Epitaxy

Abstract

The electrical detection of the surface states of topological insulators is strongly impeded by the interference of bulk conduction, which commonly arises due to pronounced doping associated with the formation of lattice defects. As exemplified by the topological insulator Bi2Te2Se, we show that via van der Waals epitaxial growth on thin hBN substrates the structural quality of such nanoplatelets can be substantially improved. The surface state carrier mobility of nanoplatelets on hBN is increased by a factor of about 3 compared to platelets on conventional Si/SiOx substrates, which enables the observation of well-developed Shubnikov-de Haas oscillations. We furthermore demonstrate the possibility to effectively tune the Fermi level position in the films with the aid of a back gate.

References in corpus (6)

• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• Hunting for Monolayer Boron Nitride: Optical and Raman Signatures
• Few-layer Nanoplates of Bi2Se3 and Bi2Te3 with Highly Tunable Chemical Potential
• Rapid Surface Oxidation as a Source of Surface Degradation Factor for Bi2Se3
• Two-dimensional magnetotransport in Bi2Te2Se nanoplatelets

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• Synthesis and characterisation of nanomaterials of the topological crystalline insulator SnTe
• Van der Waals epitaxial growth of topological insulator Bi${}_{2-x}$Sb${}_x$Te${}_{3-y}$Se${}_y$ ultrathin nanoplate on electrically insulating fluorophlogopite mica
• Versatile Large-Area Custom-Feature van der Waals Epitaxy of Topological Insulators