1. Multi-color luminescence and thermal stability of eulytite-type Ba3La(PO4)3:Ce3+,Mn2+ phosphors via gel-combustion.
- Author
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Liu, Weigang, Zhu, Qi, Wang, Xuejiao, Li, Xiaodong, Sun, Xudong, and Li, Ji-Guang
- Subjects
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PHOSPHORS , *THERMAL stability , *LUMINESCENCE , *LUMINESCENCE quenching , *ENERGY transfer , *HEAT - Abstract
Abstract Eulytite-type Ba 3 La 1- x (PO 4) 3 : x Ce3+ (x = 0–0.10) and Ba 3- y La 0.97 (PO 4) 3 :0.03Ce3+, y Mn2+ (y = 0.05–0.30) phosphors were first synthesized via gel-combustion and subsequent calcination in an Ar/H 2 atmosphere at 1250 °C. Photoluminescence properties of the phosphors were thoroughly studied, including excitation, emission, emission color, thermal stability and the process of Ce3+ → Mn2+ energy transfer. The Ba 3 La(PO 4) 3 : x Ce3+, y Mn2+ phosphor series simultaneously exhibited the near-ultraviolet emission of Ce3+ (∼370 nm, 4 f 05 d 1 → 4 f 15 d 0 transition) and the orange-red emission of Mn2+ (∼591–605 nm, 4T 1 → 6A 1 transition) upon exciting the Ce3+ ions with ∼276 nm UV light. Owing to Ce3+ → Mn2+ energy transfer most probably occurring via dipole-dipole interaction, gradually enhanced Mn2+ while weakened Ce3+ emission was resulted at a higher Mn2+ content, with which the emission color can be adjusted from blue through reddish-purple and ultimately to orange red. The efficiency of the energy transfer was analyzed to reach its maximum of ∼43.2% at y = 0.30. It was shown that the Ba 3 La 1- x (PO 4) 3 : x Ce3+ and Ba 3- y La 0.97 (PO 4) 3 :0.03Ce3+, y Mn2+ phosphor series both have favorable thermal stabilities, whose activation energy for thermal quenching of luminescence was calculated to be ∼0.28 ± 0.02 eV for Ce3+ in the former while ∼0.22 ± 0.01 eV for Ce3+ and ∼0.21 ± 0.01 eV for Mn2+ in the latter system. Increasing temperature did not alter the emission wavelength of Ce3+ but gradually blue-shifted that of Mn2+ from ∼602 to 583 nm with increasing temperature from 25 to 200 °C. Graphical abstract Image 1 Highlights • Gel-combustion produced Ce3+ and Ce3+/Mn2+ doped Ba 3 La(PO 4) 3 phosphors. • Photoluminescence properties of the phosphors were thoroughly analyzed. • The mechanism and efficiency of Ce3+.→Mn2+ energy transfer were determined. • Favorable thermal stabilities were demonstrated for the phosphors. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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