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

Ngoc Han Tu; Yoichi Tanabe; Khuong Kim Huynh; Yohei Sato; Hidetoshi Oguro; Satoshi Heguri; Kenji Tsuda; Masami Terauchi; Kazuo Watanabe; Katsumi Tanigaki

doi:10.1063/1.4892576

arXiv · 1407.7675

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

Ngoc Han Tu·Yoichi Tanabe·Khuong Kim Huynh·Yohei Sato·Hidetoshi Oguro·Satoshi Heguri·Kenji Tsuda·Masami Terauchi·Kazuo Watanabe·Katsumi Tanigaki

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Abstract

We report the growth of high quality Bi$_{2-x}$Sb$_x$Te$_{3-y}$Se$_y$ ultrathin nanoplates (BSTS-NPs) on an electrically insulating fluorophlogopite mica substrate using a catalyst-free vapor solid method. Under an optimized pressure and suitable Ar gas flow rate, we control the thickness, the size and the composition of BSTS-NPs. Raman spectra showing systematic change indicate that the thicknesses and compositions of BSTS-NPs are indeed accurately controlled. Electrical transport demonstrates that a robust Dirac cone carrier transport in BSTS-NPs. Since BSTS-NPs provide superior dominant surface transport of the tunable Dirac cone surface states with negligible contribution of the conduction of the bulk states, BSTS-NPs provide an ideal platform to explore intrinsic physical phenomena as well as technological applications of 3-dimensional topological insulators in the future.

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Ngoc Han Tu, Yoichi Tanabe, Khuong Kim Huynh, Yohei Sato, Hidetoshi Oguro, Satoshi Heguri, Kenji Tsuda, Masami Terauchi, Kazuo Watanabe, Katsumi Tanigaki. 2014-07-29. 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. https://doi.org/10.1063/1.4892576

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