Luminescence properties of a new greenish blue emitting phosphor Na5Ca4(PO4)4F:Eu2+
| Autor: | Zhiguo Xia, Libing Liao, Jun Zhou, Haiyi Xiao, Jiaqing Zhuang |
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| Rok vydání: | 2012 |
| Předmět: |
Materials science
Photoluminescence business.industry Mechanical Engineering Metals and Alloys Analytical chemistry Phosphor medicine.disease_cause law.invention Mechanics of Materials law Materials Chemistry medicine Optoelectronics Quantum efficiency Emission spectrum business Luminescence Ultraviolet Powder diffraction Light-emitting diode |
| Zdroj: | Journal of Alloys and Compounds. 534:97-100 |
| ISSN: | 0925-8388 |
| DOI: | 10.1016/j.jallcom.2012.04.042 |
| Popis: | A novel greenish blue emitting phosphor, Na 5 Ca 4 (PO 4 ) 4 F:Eu 2+ , was synthesized by a conventional solid-state reaction, and its phase formation was confirmed by using the X-ray powder diffraction (XRD) technique. The photoluminescence (PL) results showed that the phosphor could be efficiently excited by ultraviolet (UV) light at wavelength of 250–410 nm, and it exhibited bright greenish blue emission under 365 nm UV light. The emission spectrum showed a single broad band centered at 500 nm, corresponding to the 4 f 6 5 d 1 → 4 f 7 transition of Eu 2+ . Eu 2+ concentration dependent PL properties in Na 5 Ca 4 (PO 4 ) 4 F: x Eu 2+ indicated that there was a dipole–dipole interaction of Eu 2+ ions. The critical energy-transfer distance was around 19.8 A. Furthermore, this phosphor had good thermal stability and its thermal quenching activation energy was 0.45 eV. The measured quantum efficiency of Na 5 Ca 4 (PO 4 ) 4 F:0.01Eu 2+ phosphor under 365 nm excitation is 76%, which means that the present phosphor is promising in the white light emitting diodes (LEDs) phosphors. |
| Databáze: | OpenAIRE |
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