Anisotropic Electronic Structure and Interfacial Chemical Reaction of Stanene/Bi₂Te₃

Stanene, composed of tin atoms and arranged in a single layer, is the tin analogue of graphene and predicted by the past studies to be a 2D topological insulator, which has aroused extensive research interest in recent years since it was fabricated on the substrate Bi₂Te₃(111) by molecular beam epitaxy. But so far, the hexagonal deformation of the Fermi surface of stanene and the interfacial interaction between tin atoms and the substrate Bi₂Te₃ are still not properly revealed by experiments. Here, the entire and anisotropic electronic band structure of stanene has been investigated in detail by angle-resolved photoemission spectroscopy. The anisotropic electronic band structure can explain the anisotropic electronic properties and the anisotropic transport behavior in different directions of stanene. Moreover, the interfacial chemical reaction and Sn–Te chemical bonding are revealed though the subtle chemical shift of the core level measured by high-resolution synchrotron radiation X-ray photoemission spectroscopy, which has been largely misunderstood in previous works. The experimental results demonstrate it is necessary to rethink the formation of stanene on the substrate Bi₂Te₃.