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arXiv · 2404.17203

Band structure of Bi surfaces formed on Bi2Se3 upon exposure to air

Alexandre Gauthier·Jonathan A. Sobota·Nicolas Gauthier·Costel R. Rotundu·Zhi-Xun Shen·Patrick S. Kirchmann
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Abstract

Bi$_2$Se$_3$ has been the focus of intense interest over the past decade due to its topological properties. Bi surfaces are known to form on Bi$_2$Se$_3$ upon exposure to atmosphere, but their electronic structure has not been investigated. We report band structure measurements of such Bi surfaces using angle-resolved photoemission spectroscopy. Measured spectra can be well explained by the band structure of a single bilayer of Bi on Bi$_2$Se$_3$, and show that Bi surfaces consistently dominate the photoemission signal for air exposure times of at least 1 hour. These results demonstrate that atmospheric effects should be taken into consideration when identifying two-dimensional transport channels, and when designing surface-sensitive measurements of Bi$_2$Se$_3$, ideally limiting air exposure to no more than a few minutes.

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Alexandre Gauthier, Jonathan A. Sobota, Nicolas Gauthier, Costel R. Rotundu, Zhi-Xun Shen, Patrick S. Kirchmann. 2024-04-26. Band structure of Bi surfaces formed on Bi2Se3 upon exposure to air. https://doi.org/10.1103/physrevmaterials.8.054201

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