Real-space characterization of reactivity towards water at Bi2Te3(111) surface

Abstract

Surface reactivity is important in modifying the physical and chemical properties of surface sensitive materials, such as the topological insulators (TIs). Even though many studies addressing the reactivity of TIs towards external gases have been reported, it is still under heavy debate whether and how the topological insulators react with H${}_2$O. Here, we employ scanning tunneling microscopy (STM) to directly probe the surface reaction of Bi${}_2$Te${}_3$ towards H${}_2$O. Surprisingly, it is found that only the top quintuple layer is reactive to H${}_2$O, resulting in a hydrated Bi bilayer as well as some Bi islands, which passivate the surface and prevent from the subsequent reaction. A reaction mechanism is proposed with H${}_2$Te and hydrated Bi as the products. Unexpectedly, our study indicates the reaction with water is intrinsic and not dependent on any surface defects. Since water inevitably exists, these findings provide key information when considering the reactions of Bi${}_2$Te${}_3$ with residual gases or atmosphere.

17 pages, 5 figures, accepted, Phys. Rev. B (2016)

References in corpus (5)

• First direct observation of Spin-textures in Topological Insulators : Spin-resolved ARPES as a probe of topological quantum spin Hall effect and Berry's phase
• Coexistence of the topological state and a two-dimensional electron gas on the surface of Bi2Se3
• Rapid Surface Oxidation as a Source of Surface Degradation Factor for Bi2Se3
• Spin-orbit interaction effect in the electronic structure of \BiTe \ observed by angle-resolved photoemission spectroscopy
• Intrinsic conduction through topological surface states of insulating Bi${}_2$Te${}_3$ epitaxial thin films

Cited by in corpus (1)

• Atmosphere loss in planet-planet collisions