{"title":"In-situ preparation and characterization of defect-free topological insulator surfaces","authors":"Shreyashi Sinha, Sujit Manna","doi":"10.1016/j.surfin.2025.106171","DOIUrl":null,"url":null,"abstract":"<div><div>Atomically clean and defect-free surface of topological insulators (TI) are essential for reliable quantum application such as the quantum Hall effect, topological superconductivity. We report an alternative and efficient method for preparing clean, defect-free and atomically flat surface of topological insulators compared to conventional <em>in-situ</em> cleaving of single crystals. Scanning tunneling microscopy (STM) measurements reveal that <em>in-vacuo</em> cleaving produces a smooth surface with large terraces but results in atomic native surface defects. Over time, surface contamination roughens the surface and repeated cleaving becomes impractical for thin samples. Argon ion bombardment followed by <em>in-situ</em> e-beam annealing effectively restored a clean surface with fewer defects, eliminating the need of removing the sample from the vacuum for fresh cleaving. Atomic-resolved imaging and spectroscopic measurements revealed detailed surface structures, defect geometries and local density of states for TI (Bi<sub>0.1</sub>Sb<sub>0.9</sub>)<sub>2</sub>Te<sub>3</sub>(0001) surface. With further optimization of the e-beam annealing parameters, a completely defect-free pristine surface was obtained as evidenced by spatially resolved differential conductance (dI/dU) measurements. We successfully extended this method to prepare clean defect-free surface of SnTe(001), a pristine topological crystalline insulator. It provides strong evidence to remove surface contaminants and imperfections, thereby ensuring its potential for broad application in the preparation of various 2D materials.</div></div>","PeriodicalId":22081,"journal":{"name":"Surfaces and Interfaces","volume":"62 ","pages":"Article 106171"},"PeriodicalIF":5.7000,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Surfaces and Interfaces","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2468023025004304","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Atomically clean and defect-free surface of topological insulators (TI) are essential for reliable quantum application such as the quantum Hall effect, topological superconductivity. We report an alternative and efficient method for preparing clean, defect-free and atomically flat surface of topological insulators compared to conventional in-situ cleaving of single crystals. Scanning tunneling microscopy (STM) measurements reveal that in-vacuo cleaving produces a smooth surface with large terraces but results in atomic native surface defects. Over time, surface contamination roughens the surface and repeated cleaving becomes impractical for thin samples. Argon ion bombardment followed by in-situ e-beam annealing effectively restored a clean surface with fewer defects, eliminating the need of removing the sample from the vacuum for fresh cleaving. Atomic-resolved imaging and spectroscopic measurements revealed detailed surface structures, defect geometries and local density of states for TI (Bi0.1Sb0.9)2Te3(0001) surface. With further optimization of the e-beam annealing parameters, a completely defect-free pristine surface was obtained as evidenced by spatially resolved differential conductance (dI/dU) measurements. We successfully extended this method to prepare clean defect-free surface of SnTe(001), a pristine topological crystalline insulator. It provides strong evidence to remove surface contaminants and imperfections, thereby ensuring its potential for broad application in the preparation of various 2D materials.
期刊介绍:
The aim of the journal is to provide a respectful outlet for ''sound science'' papers in all research areas on surfaces and interfaces. We define sound science papers as papers that describe new and well-executed research, but that do not necessarily provide brand new insights or are merely a description of research results.
Surfaces and Interfaces publishes research papers in all fields of surface science which may not always find the right home on first submission to our Elsevier sister journals (Applied Surface, Surface and Coatings Technology, Thin Solid Films)