Multiple low-energy excitons and optical response of d0 double perovskite Ba2ScTaO6

Himanshu, A.K.; Kumar, Sujit; Dey, Urmimala; Ray, Rajyavardhan

Abstract

Large bandgap insulators are considered promising for applications such as photocatalysts, dielectric resonators and interference lters. Based on synchrotron X-ray diraction, diuse re ectance measurement and density functional theory, we report the crystal structure, optical response, and electronic properties of the synthesized d0 double perovskite Ba2ScTaO6. In contrast to earlier prediction, the electronic bandgap is found to be large, 4:66 eV. The optical response is characterized by the presence of multiple exciton modes extending up to the visible range. A detailed investigation of the direct gap excitons based on the Elliot formula is presented. Density functional theory based investigation of the electronic properties within generalized gradient approximation severely underestimates the electronic gap. To reach a quantitative agreement, we consider dierent available avors of the modied-Becke-Johnson exchange-correlation potential and discuss their eects on the electronic and optical properties.

Citation

Himanshu, A., Kumar, S., Dey, U., & Ray, R. (2022). Multiple low-energy excitons and optical response of d0 double perovskite Ba2ScTaO6. Physica B: Condensed Matter, 637, Article 413856. https://doi.org/10.1016/j.physb.2022.413856

• Journal Article Type: Article
• Acceptance Date: Mar 19, 2022
• Online Publication Date: Apr 12, 2022
• Publication Date: Jul 15, 2022
• Deposit Date: Apr 26, 2022
• Publicly Available Date: Apr 12, 2023
• Journal: Physica B: Condensed Matter
• Print ISSN: 0921-4526
• Electronic ISSN: 1873-2135
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 637
• Article Number: 413856
• DOI: https://doi.org/10.1016/j.physb.2022.413856
• Public URL: https://durham-repository.worktribe.com/output/1207691