Termination of Single Crystal Bi2Se3 Surfaces Prepared by Various Methods

Abstract

Bismuth Selenide (Bi2Se3) is a topological insulator with a two-dimensional layered structure that enables clean and well-ordered surfaces to be prepared by cleaving. Although some studies have demonstrated that the cleaved surface is terminated with Se, as expected from the bulk crystal structure, other reports have indicated either a Bi- or mixed-termination. Low energy ion scattering (LEIS), low energy electron diffraction (LEED) and x-ray photoelectron spectroscopy (XPS) are used here to compare surfaces prepared by ex situ cleaving, in situ cleaving, and ion bombardment and annealing (IBA) in ultra-high vacuum (UHV). Surfaces prepared by in situ cleaving and IBA are well ordered and Se-terminated. Ex situ cleaved samples could be either Se-terminated or Bi-rich, are less well ordered and have adsorbed contaminants. This suggests that a chemical reaction involving atmospheric contaminants, which may preferentially adsorb at surface defects, could contribute to the non-reproducibility of the termination.

31 pages, 10 figures, 1 table

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• Quantum Anomalous Hall Effect in Hg${}_{1-y}$Mn${}_y$Te Quantum Wells
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Cited by in corpus (6)

• Preparation of clean surfaces and Se vacancy formation in Bi${}_2$Se${}_3$ by ion bombardment and annealing
• Electronic correlation determining correlated plasmons in Sb-doped Bi${}_2$Se${}_3$
• The growth of bismuth on Bi${}_2$Se${}_3$ and the stability of the first bilayer
• Spatial Distribution of Topological Surface State Electrons in Bi${}_2$Te${}_3$ Probed by Low Energy Na${}^{+}$ Ion Scattering
• Spatial Distribution of Topological Surface State Electrons in Bi${}_2$Se${}_3$ Probed by Na${}^{+}$ Low Energy Ion Scattering
• Halogen adsorption and reaction with Bi${}_2$(Se,Te)${}_3$ and Bi/Bi${}_2$(Se,Te)${}_3$