Surface Structure of In Situ Cleaved Single Crystal Bi2Se3 Measured by Low Energy Ion Scattering

TL;DR

This study uses low energy ion scattering to analyze the surface structure of in situ cleaved Bi2Se3, confirming a Se-terminated surface consistent with cleaving between quintuple layers and providing insights into surface relaxation.

Contribution

The paper provides experimental evidence and molecular dynamics simulation comparison to determine the surface termination and relaxation of Bi2Se3 after UHV cleaving.

Findings

Bi2Se3 cleaved under UHV has a Se-terminated surface

Surface relaxation estimates are provided from simulations

Experimental data confirms cleaving occurs between quintuple layers

Abstract

Bismuth Selenide is a two-dimensional topological insulator material composed of stacked quintuple layers (QL). The layers are held together by a weak van der Waals force that enables surface preparation by cleaving. Low energy ion scattering experiments (LEIS) show that Bi2Se3 cleaved under ultra-high vacuum (UHV) has a Se-terminated structure that is consistent with cleaving between QLs. Comparison of experimental data to molecular dynamics simulations confirms the Se-termination and provides an estimate of the surface relaxation.