1. Remarkable structure and luminescence regulation of a Gd2LuAl5O12:Ce garnet phosphor with a Ca2+/Si4+ pair for high-quality w-WLED lighting.
- Author
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Meng, Qinghong, Zhao, Guoying, Zhu, Qi, Sun, Xudong, and Li, Ji-Guang
- Subjects
LUMINESCENCE ,PHOSPHORS ,GARNET ,CELL contraction ,RIETVELD refinement ,GADOLINIUM ,CHEMICAL bond lengths - Abstract
Doping Gd
2 LuAl5 O12 :Ce with a Ca2+ /Si4+ pair produced a series of Gd1.97−x LuCax Al5−x Six O12 :0.03Ce (x = 0.0–1.2) garnet new phosphors, and remarkable regulation of the crystal structure and Ce3+ luminescence was achieved. Rietveld refinement and spectral analysis revealed that greater incorporation of Ca2+ /Si4+ led to a higher lattice rigidity by cell contraction, a narrower bandgap, a longer average bond length/less distortion of the [CeO8 ] dodecahedron and decreased centroid shift/crystal field splitting of the Ce3+ 5d energy level. A blue-shifted 4f–5d1 transition, a narrower emission band, improved thermal stability of luminescence and a shorter fluorescence lifetime were observed with increasing Ca2+ /Si4+ content. Applying the yellowish-green-emitting Gd0.77 LuCa1.2 Al3.8 Si1.2 O12 :0.03Ce optimal phosphor (x = 1.2), together with a commercial CaAlSiN3 :Eu red phosphor, in 450 nm-excited LED lighting produced a low CCT of ∼3625 K and a high CRI/R9 of ∼95.2/94.8, indicating that the phosphor has application potential in high-performance w-WLED. [ABSTRACT FROM AUTHOR]- Published
- 2022
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