Eu3+ Site Distribution and Local Distortion of Photoluminescent Ca3WO6:(Eu3+, K+) Double Perovskites as High‐Color‐Purity Red Phosphors
Abstract In this study, Eu3+ and K+ co‐doped Ca3WO6 double perovskite, a high‐color‐purity red phosphor, is quantitatively investigated using synchrotron X‐ray diffraction Rietveld refinement, energy dispersive X‐ray spectroscopy, and high‐resolution PL spectroscopy. The Eu3+ fluorescence line‐narro...
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| Format: | Article |
| Language: | English |
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Wiley
2023-11-01
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| Series: | Advanced Science |
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| Online Access: | https://doi.org/10.1002/advs.202302559 |
| _version_ | 1797637369430540288 |
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| author | Takahito Otsuka Ryohei Oka Tomokatsu Hayakawa |
| author_facet | Takahito Otsuka Ryohei Oka Tomokatsu Hayakawa |
| author_sort | Takahito Otsuka |
| collection | DOAJ |
| description | Abstract In this study, Eu3+ and K+ co‐doped Ca3WO6 double perovskite, a high‐color‐purity red phosphor, is quantitatively investigated using synchrotron X‐ray diffraction Rietveld refinement, energy dispersive X‐ray spectroscopy, and high‐resolution PL spectroscopy. The Eu3+ fluorescence line‐narrowing (FLN) results, used to estimate the Eu3+ occupation at given sites (so‐called A and B sites) in the host crystal (A2BMO6; A, B = Ca; M = W), reveal that the Eu3+ ions have a twin distribution in both the A and B sites with high asymmetry ratios of ΛA = 9.7 and ΛB = 10.7, respectively. More interestingly, at lower Eu3+ doping levels, the ions are predominantly located at the B sites (≈75%), indicating that the high color purity of Ca3WO6:(Eu3+, K+) is mainly caused by the high asymmetry ratios of the Eu3+ sites. Rietveld refinement combined with the FLN technique provides more reliable results for increasing the Eu3+ substitution at the A site with Eu3+ and K+ doping concentrations, which lower the lattice energy of Ca3WO6:(Eu3+, K+). The structural distortions owing to K+ co‐doping in terms of the quadratic elongation and bond‐angle variance exhibit good correlations with the Ca(Eu)O12 A‐site cuboctahedra and Ca(Eu)O6 B‐site octahedra, partially accounting for the higher Λ values. |
| first_indexed | 2024-03-11T12:47:22Z |
| format | Article |
| id | doaj.art-1734cb73023745899a10f0de24932770 |
| institution | Directory Open Access Journal |
| issn | 2198-3844 |
| language | English |
| last_indexed | 2024-03-11T12:47:22Z |
| publishDate | 2023-11-01 |
| publisher | Wiley |
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| series | Advanced Science |
| spelling | doaj.art-1734cb73023745899a10f0de249327702023-11-04T08:56:53ZengWileyAdvanced Science2198-38442023-11-011031n/an/a10.1002/advs.202302559Eu3+ Site Distribution and Local Distortion of Photoluminescent Ca3WO6:(Eu3+, K+) Double Perovskites as High‐Color‐Purity Red PhosphorsTakahito Otsuka0Ryohei Oka1Tomokatsu Hayakawa2Field of Advanced Ceramics Department of Life Science and Applied Chemistry Graduate School of Engineering Nagoya Institute of Technology Gokiso, Showa Nagoya Aichi 466‐8555 JapanField of Advanced Ceramics Department of Life Science and Applied Chemistry Graduate School of Engineering Nagoya Institute of Technology Gokiso, Showa Nagoya Aichi 466‐8555 JapanField of Advanced Ceramics Department of Life Science and Applied Chemistry Graduate School of Engineering Nagoya Institute of Technology Gokiso, Showa Nagoya Aichi 466‐8555 JapanAbstract In this study, Eu3+ and K+ co‐doped Ca3WO6 double perovskite, a high‐color‐purity red phosphor, is quantitatively investigated using synchrotron X‐ray diffraction Rietveld refinement, energy dispersive X‐ray spectroscopy, and high‐resolution PL spectroscopy. The Eu3+ fluorescence line‐narrowing (FLN) results, used to estimate the Eu3+ occupation at given sites (so‐called A and B sites) in the host crystal (A2BMO6; A, B = Ca; M = W), reveal that the Eu3+ ions have a twin distribution in both the A and B sites with high asymmetry ratios of ΛA = 9.7 and ΛB = 10.7, respectively. More interestingly, at lower Eu3+ doping levels, the ions are predominantly located at the B sites (≈75%), indicating that the high color purity of Ca3WO6:(Eu3+, K+) is mainly caused by the high asymmetry ratios of the Eu3+ sites. Rietveld refinement combined with the FLN technique provides more reliable results for increasing the Eu3+ substitution at the A site with Eu3+ and K+ doping concentrations, which lower the lattice energy of Ca3WO6:(Eu3+, K+). The structural distortions owing to K+ co‐doping in terms of the quadratic elongation and bond‐angle variance exhibit good correlations with the Ca(Eu)O12 A‐site cuboctahedra and Ca(Eu)O6 B‐site octahedra, partially accounting for the higher Λ values.https://doi.org/10.1002/advs.202302559double perovskitesEu3+ red phosphorsfluorescence line‐narrowinglocal distortionsrietveld analysis |
| spellingShingle | Takahito Otsuka Ryohei Oka Tomokatsu Hayakawa Eu3+ Site Distribution and Local Distortion of Photoluminescent Ca3WO6:(Eu3+, K+) Double Perovskites as High‐Color‐Purity Red Phosphors Advanced Science double perovskites Eu3+ red phosphors fluorescence line‐narrowing local distortions rietveld analysis |
| title | Eu3+ Site Distribution and Local Distortion of Photoluminescent Ca3WO6:(Eu3+, K+) Double Perovskites as High‐Color‐Purity Red Phosphors |
| title_full | Eu3+ Site Distribution and Local Distortion of Photoluminescent Ca3WO6:(Eu3+, K+) Double Perovskites as High‐Color‐Purity Red Phosphors |
| title_fullStr | Eu3+ Site Distribution and Local Distortion of Photoluminescent Ca3WO6:(Eu3+, K+) Double Perovskites as High‐Color‐Purity Red Phosphors |
| title_full_unstemmed | Eu3+ Site Distribution and Local Distortion of Photoluminescent Ca3WO6:(Eu3+, K+) Double Perovskites as High‐Color‐Purity Red Phosphors |
| title_short | Eu3+ Site Distribution and Local Distortion of Photoluminescent Ca3WO6:(Eu3+, K+) Double Perovskites as High‐Color‐Purity Red Phosphors |
| title_sort | eu3 site distribution and local distortion of photoluminescent ca3wo6 eu3 k double perovskites as high color purity red phosphors |
| topic | double perovskites Eu3+ red phosphors fluorescence line‐narrowing local distortions rietveld analysis |
| url | https://doi.org/10.1002/advs.202302559 |
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