Enhancement of photoluminescence properties and modification of crystal structures of Si{sub 3}N{sub 4} doping Li{sub 2}Sr{sub 0.995}SiO{sub 4}:0.005Eu{sup 2+} phosphors

Journal Article · Thu Oct 15 04:00:00 EDT 2015 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2015.04.056· OSTI ID:22475913

Song, Kaixin ^[1]; Zhang, Fangfang ^[1]; Chen, Daqin ^[2]; Wu, Song; Zheng, Peng ^[1]; Huang, Qingming ^[3]; Jiang, Jun ^[4]; Xu, Junming; Qin, Huibin ^[1]

---

1. College of Electronic Information and Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China)
2. College of Materials Sciences and Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China)
3. Instrument Analysis and Testing Center, Fuzhou University, Fuzhou 350002 (China)
4. Ningbo Institute of Materials Technologies and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

Highlights: • Si{sub 3}N{sub 4} modified Li{sub 2}Sr{sub 0.995}SiO{sub 4}:0.005Eu{sup 2+} phosphors were prepared. • The luminescence intensity of Li{sub 2}Sr{sub 0.995}SiO{sub 4}:Eu{sup 2+} was enhanced by doping Si{sub 3}N{sub 4}. • The fluorescence decay times and thermal stability were enhanced by doping Si{sub 3}N{sub 4}. - Abstract: Si{sub 3}N{sub 4} modified Li{sub 2}Sr{sub 0.995}SiO{sub 4}:0.005Eu{sup 2+} (Li{sub 2}Sr{sub 0.995}SiO{sub 4−3x/2}N{sub x}:0.005Eu{sup 2+}) phosphors were synthesized with the conventional solid-state reaction in the reduced atmosphere. The crystal structure and vibrational modes were analyzed by X-ray diffraction, Raman scattering spectroscopy and Rietveld crystal structure refinement. Photoluminescence (PL) and photoluminescence excitation (PLE) spectra showed that Li{sub 2}Sr{sub 0.995}SiO{sub 4−3x/2}N{sub x}:0.005Eu{sup 2+} powder exhibited a broad yellow emission band centered at 560 nm under the excitation of 460 nm visible light, due to the 4f{sup 6}5d{sup 1} → 4f{sup 7} transition of Eu{sup 2+}. The partial nitridation of Li{sub 2}Sr{sub 0.995}SiO{sub 4−3x/2}N{sub x}:0.005Eu{sup 2+} (x = 0.01) phosphors led to a large enhancement in the luminescence intensity, as much as 190%. At the same time, the fluorescence decay behavior curves further showed that the photoluminescence efficiencies of Li{sub 2}Sr{sub 0.995}SiO{sub 4−3x/2}N{sub x}:0.005Eu{sup 2+} phosphors were enhanced by addition of Si{sub 3}N{sub 4}. The temperature quenching characteristics confirmed that the oxynitride based Li{sub 2}Sr{sub 0.995}SiO{sub 4−3x/2}N{sub x}:0.005Eu{sup 2+} showed slightly higher stability. It is implied that Li{sub 2}Sr{sub 0.995}SiO{sub 4−3x/2}N{sub x}:0.005Eu{sup 2+} phosphors had a possible potential application on white LEDs to match blue light chips.

• OSTI ID: 22475913
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Vol. 70; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL STRUCTURE
EUROPIUM ADDITIONS
EXCITATION
FLUORESCENCE
LITHIUM COMPOUNDS
MODIFICATIONS
OPTICAL PROPERTIES
PHOSPHORS
PHOTOLUMINESCENCE
POWDERS
QUENCHING
RAMAN EFFECT
SILICATES
SILICON NITRIDES
SPECTRA
SPECTROSCOPY
STABILITY
STRONTIUM COMPOUNDS
VISIBLE RADIATION
X-RAY DIFFRACTION