Revealing localized excitons in WSe₂/β-Ga₂O₃

Author(s):Show less -

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

• Document type: Journal article
• Source: Applied Physics Letters; v. 124, n. 14, p. 7-pg., 2024-04-01.

Abstract

We have investigated the optical and magneto-optical properties of monolayer (ML) WSe2 on flakes of beta-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 approximate to-7 and approximate to-12, which were associated with the hybridization of strain localized dark excitons and defects. The reported results suggest that beta-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. (AU)

• FAPESP's process: 22/08329-0 - Effect of Moiré pattern on physical properties of twisted van der Waals heterostructures
• Grantee: Yara Galvão Gobato
• Support Opportunities: Regular Research Grants
• FAPESP's process: 23/11265-7 - Effect of Moire patterns on physical properties of van der Waals heterostructures
• Grantee: José Roberto de Toledo
• Support Opportunities: Scholarships in Brazil - Support Program for Fixating Young Doctors