Growth of Bi2Te3 topological insulator ultra-thin layers via molecular beam epitaxy on GaAs (100)

• Published in: Journal of applied physics 2023-08, Vol.134 (8)
• Main Authors: Rodrigues, Leonarde N., de Araujo, C. I. L., Mello, S. L. A., Laverock, J., Fonseca, Jakson M., Schwarzacher, W., Inoch, Wesley F., Ferreira, Sukarno O.
• Format: Article
• Language: English
• Subjects: Applied physics; Epitaxial growth; Gallium arsenide; Microscopy; Molecular beam epitaxy; Photoelectrons; Raman spectroscopy; Spintronics; Substrates; Tellurium; Thin films; Topological insulators
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/5.0155332

Ultra-thin layers ( < 8 nm) of a Bi 2Te 3 topological insulator have been grown on GaAs (100) substrates using molecular beam epitaxy. The growth was performed from a single Bi 2Te 3 effusion cell and one source of extra tellurium. Optical and structural characterizations were carried out through Raman spectroscopy, x-ray diffraction, atomic force microscopy, and scanning electron microscopy. The topological insulator properties were also investigated by angle-resolved photoelectron spectroscopy. A layer of 5 nm showed Dirac cone-like linear electronic band dispersion, indicating the signature of a topological insulator with the Dirac point having large binding energy relative to the Fermi level as expected for ultra-thin films. Topological insulator properties were also investigated at the initial growth stage where deposition follows an islandlike growth mode. Our results can contribute to the development of practical chalcogenide-based thin-film spintronics devices.