Revealing localized excitons in WSe2/β-Ga2O3

Cavalini, Camila; Rabahi, Cesar; de Brito, Caique S.; Lee, Eunji; Toledo, José R.; Cazetta, Felipe F.; Fernandes de Oliveira, Raphael B.; Andrade, Marcelo B.; Henini, Mohamed; Zhang, Yuhao; Kim, Jeongyong; Barcelos, Ingrid D.; Galvão Gobato, Yara

Abstract

We have investigated the optical and magneto-optical properties of monolayer (ML) WSe2 on flakes of β-Ga2O3 under high magnetic fields. Remarkably, sharp emission peaks were observed and associated with localized excitons related to point defects. A detailed study of low-temperature photoluminescence (PL) and magneto-PL under high perpendicular magnetic field up to 9 T was carried out. Several sharp emission peaks have shown valley g-factors values close to −4, which is an unusual result for localized excitons in WSe2. Furthermore, some PL peaks have shown higher g-factor values of ≈−7 and ≈−12, which were associated with the hybridization of strain localized dark excitons and defects. The reported results suggest that β-Ga2O3 is, indeed, a promising dielectric substrate for ML WSe2 and also to explore fundamental physics in view of possible applications in quantum information technology.

• Journal Article Type: Article
• Acceptance Date: Mar 15, 2024
• Online Publication Date: Apr 1, 2024
• Publication Date: Apr 1, 2024
• Deposit Date: Apr 7, 2024
• Publicly Available Date: Apr 8, 2024
• Journal: Applied Physics Letters
• Print ISSN: 0003-6951
• Electronic ISSN: 1077-3118
• Publisher: American Institute of Physics
• Peer Reviewed: Peer Reviewed
• Volume: 124
• Issue: 14
• Article Number: 142104
• DOI: https://doi.org/10.1063/5.0203628
• Keywords: Excitons, Optoelectronics, Heterostructures, Fundamental physics, Information technology, 2D materials, Zeeman effect, Oxides, Crystallographic defects, Photoluminescence spectroscopy
• Public URL: https://nottingham-repository.worktribe.com/output/33293448