Infrared Optical Anisotropy in Quasi‐1D Hexagonal Chalcogenide BaTiSe<sub>3</sub>
Abstract Polarimetric infrared (IR) detection bolsters IR thermography by leveraging the polarization of light. Optical anisotropy, i.e., birefringence and dichroism, can be leveraged to achieve polarimetric detection. Recently, giant optical anisotropy is discovered in quasi‐1D narrow‐bandgap hexagonal perovskite sulfides, A 1+ x TiS 3 , specifically BaTiS 3 and Sr 9/8 TiS 3 . In these materials, the critical role of atomic‐scale structure modulations in the unconventional electrical, optical, and thermal properties raises the broader question of the nature of other materials that belong to this family. To address this issue, for the first time, high‐quality single crystals of a largely unexplored member of the A 1+ x TiX 3 (X = S, Se) family, BaTiSe 3 are synthesized. Single‐crystal X‐ray diffraction determined the room‐temperature structure with the P 31 c space group, which is a superstructure of the earlier reported P 6 3 / mmc structure. The crystal structure of BaTiSe 3 features antiparallel c ‐axis displacements similar to but of lower symmetry than BaTiS 3 , verified by the polarization dependent Raman spectroscopy. Fourier transform infrared (FTIR) spectroscopy is used to characterize the optical anisotropy of BaTiSe 3 , whose refractive index along the ordinary ( E ⊥ c ) and extraordinary ( E ‖ c ) optical axes is quantitatively determined by combining ellipsometry studies with FTIR. With a giant birefringence Δ n ∼ 0.9, BaTiSe 3 emerges as a new candidate for miniaturized birefringent optics for mid‐wave infrared to long‐wave infrared imaging.
Authors
- Hongyan Mei (ORCID: https://orcid.org/0000-0002-4461-7438)
- Nuh Gedik (ORCID: https://orcid.org/0000-0002-6394-4987)
- Batyr Ilyas (ORCID: https://orcid.org/0000-0002-5135-2378)
- Shantanu Singh (ORCID: https://orcid.org/0000-0001-6765-7152)
- Qian Song (ORCID: https://orcid.org/0000-0003-1193-1540)
- Jayakanth Ravichandran (ORCID: https://orcid.org/0000-0001-5030-9143)
- Tieyan Chang (ORCID: https://orcid.org/0000-0002-7434-3714)
- Stephen B. Cronin (ORCID: https://orcid.org/0000-0001-9153-7687)
- Ting‐Ran Liu
- Simon J. Teat (ORCID: https://orcid.org/0000-0001-9515-2602)
- Nicholas S. Settineri (ORCID: https://orcid.org/0000-0003-0272-454X)
- Mikhail A. Kats (ORCID: https://orcid.org/0000-0003-4897-4720)
- Riccardo Comin (ORCID: https://orcid.org/0000-0002-1069-9973)
- Yu‐Tsun Shao (ORCID: https://orcid.org/0000-0002-5574-0490)
- Jiaheng Li (ORCID: https://orcid.org/0000-0002-1172-8000)
- Yu‐Sheng Chen (ORCID: https://orcid.org/0000-0001-6593-5155)
- Zhengyu Du
- Boyang Zhao (ORCID: https://orcid.org/0000-0001-5562-2630)
Institutions
- University of Southern California (US)
- University of Wisconsin–Madison (US)
- Lawrence Berkeley National Laboratory (US)
- Chinese Academy of Sciences (CN)
- University of Chicago (US)
- Institute of Physics (CN)
- Massachusetts Institute of Technology (US)
- University of California, Berkeley (US)
Publication Details
- Journal
- Advanced Optical Materials
- Published
- 2024-09-03
- DOI
- https://doi.org/10.1002/adom.202400327
- Citations
- 8
- Primary Topic
- Perovskite Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 1.67
Funders
- National Science Foundation
- U.S. Department of Energy
- Gordon and Betty Moore Foundation
- University of Southern California
- Chinese Academy of Sciences
- Office of Science
- Multidisciplinary University Research Initiative
- Office of Naval Research
- Division of Materials Research
- Division of Chemistry
- Basic Energy Sciences
- Army Research Office