1
|
Kamada Y, Hayasaka R, Uchida K, Suzuki T, Takei T, Kitaura M, Kominami H, Hara K, Matsushima Y. Deep Red Photoluminescence from Cr 3+ in Fluorine-Doped Lithium Aluminate Host Material. MATERIALS (BASEL, SWITZERLAND) 2024; 17:338. [PMID: 38255506 PMCID: PMC10817566 DOI: 10.3390/ma17020338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 12/25/2023] [Accepted: 01/02/2024] [Indexed: 01/24/2024]
Abstract
Deep red phosphors have attracted much attention for their applications in lighting, medical diagnosis, health monitoring, agriculture, etc. A new phosphor host material based on fluorine-doped lithium aluminate (ALFO) was proposed and deep red emission from Cr3+ in this host material was demonstrated. Cr3+ in ALFO was excited by blue (~410 nm) and green (~570 nm) rays and covered the deep red to near-infrared region from 650 nm to 900 nm with peaks around 700 nm. ALFO was a fluorine-doped form of the spinel-type compound LiAl5O8 with slightly Li-richer compositions. The composition depended on the preparation conditions, and the contents of Li and F tended to decrease with preparation temperature, such as Al4.69Li1.31F0.28O7.55 at 1100 °C, Al4.73Li1.27F0.17O7.65 at 1200 °C, and Al4.83Li1.17F0.10O7.78 at 1300 °C. The Rietveld analysis revealed that ALFO and LiAl5O8 were isostructural with respect to the spinel-type lattice and in a disorder-order relationship in the arrangement of Li+ and Al3+. The emission peak of Cr3+ in LiAl5O8 resided at 716 nm, while Cr3+ in ALFO showed a rather broad doublet peak with the tops at 708 nm and 716 nm when prepared at 1200 °C. The broad emission peak indicated that the local environment around Cr3+ in ALFO was distorted, which was also supported by electron spin resonance spectra, suggesting that the local environment around Cr3+ in ALFO was more inhomogeneous than expected from the diffraction-based structural analysis. It was demonstrated that even a small amount of dopant (in this case fluorine) could affect the local environment around luminescent centers, and thus the luminescence properties.
Collapse
Affiliation(s)
- Yuki Kamada
- Applied Chemistry, Chemical Engineering, and Biochemical Engineering, Yamagata University, Yonezawa 992-8510, Japan
| | - Ryusei Hayasaka
- Applied Chemistry, Chemical Engineering, and Biochemical Engineering, Yamagata University, Yonezawa 992-8510, Japan
| | - Kento Uchida
- Applied Chemistry, Chemical Engineering, and Biochemical Engineering, Yamagata University, Yonezawa 992-8510, Japan
| | - Taisei Suzuki
- Applied Chemistry, Chemical Engineering, and Biochemical Engineering, Yamagata University, Yonezawa 992-8510, Japan
| | - Takahiro Takei
- Center for Crystal Science and Technology, University of Yamanashi, Kofu 400-0021, Japan;
| | - Mamoru Kitaura
- Faculty of Science, Yamagata University, Yamagata 990-8560, Japan;
| | - Hiroko Kominami
- Faculty of Engineering, Shizuoka University, Hamamatsu 432-8561, Japan;
| | - Kazuhiko Hara
- Research Institute of Electronics, Shizuoka University, Hamamatsu 432-8011, Japan;
| | - Yuta Matsushima
- Applied Chemistry, Chemical Engineering, and Biochemical Engineering, Yamagata University, Yonezawa 992-8510, Japan
| |
Collapse
|