Passivation of Bi2Te3 Topological Insulator by Transferred CVD‐Graphene: Toward Intermixing‐Free Interfaces. Issue 36 (7th December 2022)

• Record Type: Journal Article
• Authors: Galceran, Regina; Bonell, Frédéric; Camosi, Lorenzo; Sauthier, Guillaume; Gebeyehu, Zewdu M.; Esplandiu, Maria José; Arrighi, Aloïs; Fernández Aguirre, Iván; Figueroa, Adriana I.; Sierra, Juan F.; Valenzuela, Sergio O.
• Is Part Of: Advanced materials interfaces. Volume 9:Issue 36(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-07
• Subjects: Bi 2Te 3 -- graphene−topological insulator interface -- intermixing -- passivation -- XPS; Materials science -- Periodicals; 620.11
• DOI: 10.1002/admi.202201997
• Languages: English
• ISSNs: 2196-7350

Abstract

Abstract: The investigation, and ultimate application, of topological insulators, typically involve exposure to ambient conditions or their integration with metals, which lead to surface oxidation or material intermixing. X‐ray photoelectron spectroscopy (XPS) measurements that demonstrate passivated and intermixing‐free interfaces in the topological insulator Bi2 Te3 by means of dry‐transferred CVD graphene are reported. After air exposure, no traces of Bi2 Te3 oxidation are found. Furthermore, it is demonstrated that graphene acts as a very efficient metal and chalcogen diffusion barrier in Bi2 Te3 /graphene/permalloy (Py) heterostructures, which are relevant for spintronics. Such results are in stark contrast with the significant surface degradation observed in bare Bi2 Te3 under ambient conditions and the deep BiTe bonding disruption that occurs in Bi2 Te3 /Py heterostructures. These findings provide a new approach to control and engineer topological insulator interfaces for spintronic applications and a new platform to investigate the combined use of graphene and topological insulator Dirac states. Abstract : A single layer of CVD graphene, transferred in an inert atmosphere, protects the topological insulator Bi2 Te3 from oxidizing. It further acts as a remarkable diffusion barrier in Bi2 Te3 /graphene/ferromagnet (permalloy, Py) heterostructures, fully suppressing the intermixing observed in Bi2 Te3 /Py and therefore offering a route toward intermixing‐free interfaces with potential for spintronics applications with large‐scale integration.