Robust and orange-yellow-emitting Sr-rich polytypoid α-SiAlON (Sr3Si24Al6N40:Eu2+) phosphor for white LEDs
Nitrides and oxynitrides isostructural to α-Si3N4 (M-α-SiAlON, M = Sr, Ca, Li) possess superb thermally stable photoluminescence (PL) properties, making them reliable phosphors for high-power solid-state lighting. However, the synthesis of phase-pure Sr-α-SiAlON still remains a great challenge and h...
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| Format: | Article |
| Language: | English |
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Taylor & Francis Group
2024-12-01
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| Series: | Science and Technology of Advanced Materials |
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| Online Access: | https://www.tandfonline.com/doi/10.1080/14686996.2024.2396276 |
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| author | Mehdi Estili Rong-Jun Xie Kohsei Takahashi Shiro Funahashi Tohru S. Suzuki Naoto Hirosaki |
| author_facet | Mehdi Estili Rong-Jun Xie Kohsei Takahashi Shiro Funahashi Tohru S. Suzuki Naoto Hirosaki |
| author_sort | Mehdi Estili |
| collection | DOAJ |
| description | Nitrides and oxynitrides isostructural to α-Si3N4 (M-α-SiAlON, M = Sr, Ca, Li) possess superb thermally stable photoluminescence (PL) properties, making them reliable phosphors for high-power solid-state lighting. However, the synthesis of phase-pure Sr-α-SiAlON still remains a great challenge and has only been reported for Sr below 1.35 at.% as the large size of Sr2+ ions tends to destabilize the α-SiAlON structure. Here, we succeeded to synthesize the single-phase powders of a unique ‘Sr-rich’ polytypoid α-SiAlON (Sr3Si24Al6N40:Eu2+) phosphor with three distinctive Sr/Eu luminescence sites using a solid-state remixing-reannealing process. The Sr content of this polytypoid structure exceeds those of a few previously reported structures by over 200%. The phase purity, composition, structure, and PL properties of this phosphor were investigated. A single phase can be obtained by firing the stoichiometric mixtures of all-nitride precursors at 2050°C under a 0.92 MPa N2 atmosphere. The Sr3Si24Al6N40:Eu2+ shows an intense orange-yellow emission, with the emission maximum of 590 nm and internal/external quantum efficiency of 66%/52% under 400 nm excitation. It also has a quite small thermal quenching, maintaining 93% emission intensity at 150°C. In comparison to Ca-α-SiAlON:Eu2+, this Sr counterpart shows superior quantum efficiency and thermal stability, enabling it to be an interesting orange-yellow down-conversion luminescent material for white LEDs. The experimental confirmation of the existence of such ‘Sr-rich’ SiAlON systems, in a single-phase powder form, paves the way for the design and synthesis of novel ‘Sr-rich’ SiAlON-based phosphor powders with unparalleled properties. |
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| institution | Directory Open Access Journal |
| issn | 1468-6996 1878-5514 |
| language | English |
| last_indexed | 2025-02-17T14:26:19Z |
| publishDate | 2024-12-01 |
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| series | Science and Technology of Advanced Materials |
| spelling | doaj.art-5b9bde5496ad4c5cb0683dc5719d63f52024-12-23T08:54:38ZengTaylor & Francis GroupScience and Technology of Advanced Materials1468-69961878-55142024-12-0125110.1080/14686996.2024.2396276Robust and orange-yellow-emitting Sr-rich polytypoid α-SiAlON (Sr3Si24Al6N40:Eu2+) phosphor for white LEDsMehdi Estili0Rong-Jun Xie1Kohsei Takahashi2Shiro Funahashi3Tohru S. Suzuki4Naoto Hirosaki5Research Center for Electronic and Optical Materials, National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, JapanCollege of Materials, Xiamen University, Xiamen, ChinaResearch Center for Electronic and Optical Materials, National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, JapanResearch Center for Electronic and Optical Materials, National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, JapanResearch Center for Electronic and Optical Materials, National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, JapanResearch Center for Electronic and Optical Materials, National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, JapanNitrides and oxynitrides isostructural to α-Si3N4 (M-α-SiAlON, M = Sr, Ca, Li) possess superb thermally stable photoluminescence (PL) properties, making them reliable phosphors for high-power solid-state lighting. However, the synthesis of phase-pure Sr-α-SiAlON still remains a great challenge and has only been reported for Sr below 1.35 at.% as the large size of Sr2+ ions tends to destabilize the α-SiAlON structure. Here, we succeeded to synthesize the single-phase powders of a unique ‘Sr-rich’ polytypoid α-SiAlON (Sr3Si24Al6N40:Eu2+) phosphor with three distinctive Sr/Eu luminescence sites using a solid-state remixing-reannealing process. The Sr content of this polytypoid structure exceeds those of a few previously reported structures by over 200%. The phase purity, composition, structure, and PL properties of this phosphor were investigated. A single phase can be obtained by firing the stoichiometric mixtures of all-nitride precursors at 2050°C under a 0.92 MPa N2 atmosphere. The Sr3Si24Al6N40:Eu2+ shows an intense orange-yellow emission, with the emission maximum of 590 nm and internal/external quantum efficiency of 66%/52% under 400 nm excitation. It also has a quite small thermal quenching, maintaining 93% emission intensity at 150°C. In comparison to Ca-α-SiAlON:Eu2+, this Sr counterpart shows superior quantum efficiency and thermal stability, enabling it to be an interesting orange-yellow down-conversion luminescent material for white LEDs. The experimental confirmation of the existence of such ‘Sr-rich’ SiAlON systems, in a single-phase powder form, paves the way for the design and synthesis of novel ‘Sr-rich’ SiAlON-based phosphor powders with unparalleled properties.https://www.tandfonline.com/doi/10.1080/14686996.2024.2396276White light emitting diodesphosphorsnitridesphotoluminescencepowder synthesis |
| spellingShingle | Mehdi Estili Rong-Jun Xie Kohsei Takahashi Shiro Funahashi Tohru S. Suzuki Naoto Hirosaki Robust and orange-yellow-emitting Sr-rich polytypoid α-SiAlON (Sr3Si24Al6N40:Eu2+) phosphor for white LEDs Science and Technology of Advanced Materials White light emitting diodes phosphors nitrides photoluminescence powder synthesis |
| title | Robust and orange-yellow-emitting Sr-rich polytypoid α-SiAlON (Sr3Si24Al6N40:Eu2+) phosphor for white LEDs |
| title_full | Robust and orange-yellow-emitting Sr-rich polytypoid α-SiAlON (Sr3Si24Al6N40:Eu2+) phosphor for white LEDs |
| title_fullStr | Robust and orange-yellow-emitting Sr-rich polytypoid α-SiAlON (Sr3Si24Al6N40:Eu2+) phosphor for white LEDs |
| title_full_unstemmed | Robust and orange-yellow-emitting Sr-rich polytypoid α-SiAlON (Sr3Si24Al6N40:Eu2+) phosphor for white LEDs |
| title_short | Robust and orange-yellow-emitting Sr-rich polytypoid α-SiAlON (Sr3Si24Al6N40:Eu2+) phosphor for white LEDs |
| title_sort | robust and orange yellow emitting sr rich polytypoid α sialon sr3si24al6n40 eu2 phosphor for white leds |
| topic | White light emitting diodes phosphors nitrides photoluminescence powder synthesis |
| url | https://www.tandfonline.com/doi/10.1080/14686996.2024.2396276 |
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