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Site-selective and cooperative doping of Gd3Al5O12:Ce garnets for structural stabilization and warm WLED lighting of low CCT and high CRI.
- Source :
- Dalton Transactions: An International Journal of Inorganic Chemistry; 1/14/2022, Vol. 51 Issue 2, p645-654, 10p
- Publication Year :
- 2022
-
Abstract
- Synergistic doping of the metastable Gd<subscript>3</subscript>Al<subscript>5</subscript>O<subscript>12</subscript>:Ce garnet with a Ca<superscript>2+</superscript>/Hf<superscript>4+</superscript> pair and Sc<superscript>3+</superscript> to form Gd<subscript>2.97−x</subscript>Ca<subscript>x</subscript>Hf<subscript>x</subscript>Sc<subscript>y</subscript>Al<subscript>3</subscript>O<subscript>12</subscript>:0.03Ce (x = 0.5–2.0, y = 0.0–1.5, x + y = 2.0) solid solution was conducted for the structural stabilization and photoluminescence manipulation. The site selection of Ca<superscript>2+</superscript>/Hf<superscript>4+</superscript>/Sc<superscript>3+</superscript> dopants and the effects of doping on the crystal structure, local coordination, band structure and Ce<superscript>3+</superscript> luminescence were revealed in detail with the results of XRD, Rietveld refinement, TEM, and UV-Vis/photoluminescence spectroscopy. A decrease in Ca<superscript>2+</superscript>/Hf<superscript>4+</superscript> and an increase in the Sc<superscript>3+</superscript> content were observed to shrink the lattice, widen the bandgap of the garnet host, red-shift the excitation/emission wavelength, broaden the emission band and shorten the fluorescence lifetime of Ce<superscript>3+</superscript>. The spectral changes were rationalized by considering the local coordination and crystal field splitting of the Ce<superscript>3+</superscript> 5d energy level. Application of typical Gd<subscript>0.97</subscript>Ca<subscript>2</subscript>Hf<subscript>2</subscript>Al<subscript>3</subscript>O<subscript>12</subscript>:0.03Ce (x = 2.0, y = 0) cyan and Gd<subscript>2.47</subscript>Ca<subscript>0.5</subscript>Hf<subscript>0.5</subscript>Sc<subscript>1.5</subscript>Al<subscript>3</subscript>O<subscript>12</subscript>:0.03Ce (x = 0.5, y = 1.5) greenish-yellow phosphors in w-WLED lighting produced low correlated color temperatures of ∼3842 and 3514 K, high color rendering indices of ∼88 and 93 and favorable luminous efficacies of ∼32.9 and 14.7 lm/W under the excitation of 395 nm n-UV and 450 nm blue LED chips, respectively. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 14779226
- Volume :
- 51
- Issue :
- 2
- Database :
- Complementary Index
- Journal :
- Dalton Transactions: An International Journal of Inorganic Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 154476723
- Full Text :
- https://doi.org/10.1039/d1dt03599a