A new green phosphor of SrAl{sub 2}O{sub 4}:Eu{sup 2+},Ce{sup 3+},Li{sup +} for alternating current driven light-emitting diodes

Journal Article · Sat Dec 15 04:00:00 EST 2012 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2012.08.057· OSTI ID:22215655

Chen, Lei ^[1]; Zhang, Yao; Liu, Fayong; Luo, Anqi; Chen, Zhixin; Jiang, Yang ^[1]; Chen, Shifu ^[2]; Liu, Ru-Shi ^[3]

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1. School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China)
2. Department of Chemistry, Huaibei Normal University, Huaibei 235000 (China)
3. Department of Chemistry, National Taiwan University, Taipei 106, Taiwan (China)

Graphical abstract: Display Omitted Highlights: ► This work focuses on exploring new phosphors of SrAl{sub 2}O{sub 4}:Eu{sup 2+},Ce{sup 3+},Li{sup +} for AC LEDs. ► The work provides a new route to synthesize the pure phase of SrAl{sub 2}O{sub 4}. ► The formation of the impurity phase of Sr{sub 4}Al{sub 14}O{sub 25} was suppressed by using Ce{sup 3+}. ► Charger defects were compensated by using Li{sup +}. ► The luminescence intensity was enhanced significantly by co-doping Ce{sup 3+} and Li{sup +}. -- Abstract: New phosphors are desired to overcoming the flickering luminescence of alternating current light-emitting diodes (AC-LEDs) by compensating dark duration with appropriately persistent luminescence. Here, the phosphor of SrAl{sub 2}O{sub 4}:Eu{sup 2+},Ce{sup 3+},Li{sup +} was developed for this application. The phosphor was synthesized with solid-state reaction method by using H{sub 3}BO{sub 3} as flux. The XRD patterns show that the impurity phase of Sr{sub 4}Al{sub 14}O{sub 25} which always formed together with SrAl{sub 2}O{sub 4} during reaction was suppressed by using Ce. The charger defects caused by the non-equivalent substitution of Sr{sup 2+} with Ce{sup 3+} were compensated with Li{sup +}. Thus, the luminescence intensity of SrAl{sub 2}O{sub 4}:Eu{sup 2+} was enhanced significantly by co-doping Ce{sup 3+} and Li{sup +}. The fluorescence lifetime of the phosphor is about 36.5 ms. The energy dispersive spectra (EDS) assisted with scanning electron microscope (SEM) pictures reveal that Ce ions mainly distribute along grain boundary.

• OSTI ID: 22215655
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 12 Vol. 47; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ALTERNATING CURRENT
CERIUM IONS
EUROPIUM IONS
FLUORESCENCE
GRAIN BOUNDARIES
LIGHT EMITTING DIODES
LITHIUM IONS
SCANNING ELECTRON MICROSCOPY
SOLIDS
SYNTHESIS
X-RAY DIFFRACTION