Epitaxial Growth of Ternary Topological Insulator Bi₂ Te₂ Se 2D Crystals on Mica

Nanostructures of ternary topological insulator (TI) Bi₂ Te₂ Se are, in principle, advantageous to the manifestation of topologically nontrivial surface states, due to significantly enhanced surface-to-volume ratio compared with its bulk crystals counterparts. Herein, the synthesis of 2D Bi₂ Te₂ Se crystals on mica via the van der Waals epitaxy method is explored and systematically the growth behaviors during the synthesis process are investigated. Accordingly, 2D Bi₂ Te₂ Se crystals with domain size up to 50 µm large and thickness down to 2 nm are obtained. A pronounced weak antilocalization effect is clearly observed in the 2D Bi₂ Te₂ Se crystals at 2 K. The method for epitaxial growth of 2D ternary Bi₂ Te₂ Se crystals may inspire materials engineering toward enhanced manifestation of the subtle surface states of TIs and thereby facilitate their potential applications in next-generation spintronics.