Enhancement of the Surface Morphology of (Bi0.4Sb0.6)2Te3 Thin Films by In Situ Thermal Annealing

Liesbeth Mulder; Hanne van de Glind; Alexander Brinkman; Omar Concepción

doi:10.3390/nano13040763

Enhancement of the Surface Morphology of (Bi_0.4Sb_0.6)₂Te₃ Thin Films by In Situ Thermal Annealing

Nanomaterials (Basel). 2023 Feb 17;13(4):763. doi: 10.3390/nano13040763.

Authors

Liesbeth Mulder¹, Hanne van de Glind¹, Alexander Brinkman¹, Omar Concepción^{1

2}

Affiliations

¹ MESA+ Institute for Nanotechnology, University of Twente, 7500 AE Enschede, The Netherlands.
² Peter Grünberg Institute (PGI-9), Forschungszentrum Juelich, 52425 Juelich, Germany.

Abstract

The study of the exotic properties of the surface states of topological insulators requires defect-free and smooth surfaces. This work aims to study the enhancement of the surface morphology of optimally doped, high-crystalline (Bi_0.4Sb_0.6)₂Te₃ films deposited by molecular beam epitaxy on Al₂O₃ (001) substrates. Atomic force microscopy shows that by employing an in situ thermal post anneal, the surface roughness is reduced significantly, and transmission electron microscopy reveals that structural defects are diminished substantially. Thence, these films provide a great platform for the research on the thickness-dependent properties of topological insulators.

Keywords: (Bi1−xSbx)2Te3; in situ thermal post anneal; molecular beam epitaxy; smooth surfaces; topological insulator.

Grants and funding

This work was financially supported by the Netherlands Organization for Scientific Research (NWO) through a VICI grant.