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arXiv · 2602.16552

The rise and fall of an oxide: growth and evolution of Bismuth Oxide on Au(111)

Alberto Turoldo·Marco Bianchi·Deborah Perco·Andrea Berti·Philip Hofmann·Alessandro Baraldi·Silvano Lizzit
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Abstract

We report a comprehensive, multi-technique study of bismuth oxide growth on Au(111) under different conditions such as temperature and exposure to molecular oxygen. By combining synchrotron-based X-ray photoelectron spectroscopy and diffraction with low-energy electron diffraction and scanning tunneling microscopy, we elucidate the structural evolution of the system during controlled oxidation and subsequent annealing. We find that Bi deposition induces well-defined surface reconstructions, whereas oxidation triggers the formation of a complex sequence of bismuth oxide domains. High-resolution spectroscopic and diffraction data enable us to pinpoint the structure of the oxide consistent with the $(201)$ surface of $\beta$-Bi$_2$O$_3$. In addition, angle resolved photoemission experiments and work function measurements reveal substantial electronic modifications triggered by a complex interplay of segregation of Bi and Au. Notably, a work function of 3.4 eV is achieved for oxidation at 423 K. These results provide benchmark structural and electronic insights into the Bi oxide/Au(111) system and establish a framework for integrating Bi$_2$O$_3$ as a contact material in devices using two-dimensional semiconductors, where it can enable low contact resistance.

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Alberto Turoldo, Marco Bianchi, Deborah Perco, Andrea Berti, Philip Hofmann, Alessandro Baraldi, Silvano Lizzit. 2026-02-18. The rise and fall of an oxide: growth and evolution of Bismuth Oxide on Au(111). https://arxiv.org/abs/2602.16552

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