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arXiv · 1804.10229

Halogen adsorption and reaction with Bi$_2$(Se,Te)$_3$ and Bi/Bi$_2$(Se,Te)$_3$

Haoshan Zhu·Weimin Zhou·Jory A. Yarmoff
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Abstract

Bi$_2$Se$_3$ and Bi$_2$Te$_3$, and these same surfaces covered with Bi films, are exposed to Br$_2$ and Cl$_2$ in ultra-high vacuum. Low energy electron diffraction (LEED) and low energy ion scattering (LEIS) are used to investigate the surface composition before and after halogen exposure. It is found that Br$_2$ weakly chemisorbs to the Se- or Te-terminated clean surfaces and light annealing removes the adsorbates restoring the intact surfaces. In contrast, halogens dissociatively adsorb onto surfaces covered with an additional bilayer of Bi, having a p-doping effect. Annealing these halogen-covered surfaces at 130{\deg}C causes Bi atoms to be chemically etched away and the surface reverts to a Se- or Te-termination. This work shows how halogen adsorption and reaction can be used to modify the surface termination of such materials.

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Haoshan Zhu, Weimin Zhou, Jory A. Yarmoff. 2018-04-26. Halogen adsorption and reaction with Bi$_2$(Se,Te)$_3$ and Bi/Bi$_2$(Se,Te)$_3$. https://arxiv.org/abs/1804.10229

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