Photoluminescent and thermal properties of (Sr{sub 0.995−x−y−z}Ca{sub x}Ba{sub y}Mg{sub z}){sub 2}SiO{sub 4}:0.01Eu{sup 2+} phosphors for warm white light-emitting diodes

Journal Article · Thu Jan 15 04:00:00 EST 2015 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2014.09.051· OSTI ID:22420751

Li, Yao ^[1]; Ci, Zhipeng ^[2]; Peng, Yingquan ^[1]; Wang, Yuhua ^[2]; Liu, Chunjuan ^[3]

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1. Institute of Microelectronics, School of Physical Science and Technology, Lanzhou University, Lanzhou 730000 (China)
2. Institute of Materials Science, School of Physical Science and Technology, Lanzhou University, Lanzhou 730000 (China)
3. School of Electronic and Information Engineering, Lanzhou Jiaotong University, Lanzou 730070 (China)

Highlights: • The photoluminescent property of Sr{sub 2}SiO{sub 4}:Eu{sup 2+} is improved by doping Ca{sup 2+} and Ba{sup 2+}. • The emission spectra red-shift obviously by doping Ca{sup 2+} into Sr{sub 2}SiO{sub 4}:Eu{sup 2+}. • The thermal stability is enhanced by doping Ba{sup 2+} into (Sr,Ca){sub 2}SiO{sub 4}:Eu{sup 2+}. • The improved phosphors can combine blue-LED chips to generate warm white light. - Abstract: A series of phosphors (Sr{sub 0.995−x−y−z}Ca{sub x}Ba{sub y}Mg{sub z}){sub 2}SiO{sub 4}:0.01Eu{sup 2+} (0 ≤ x ≤ 0.45, 0 ≤ y ≤ 0.015, 0 ≤ z ≤ 0.35) were synthesized by solid state reaction. Their phase compositions and photoluminescent properties were investigated in detail. The X-ray diffraction analysis indicates the impurity phase of SrSiO{sub 3} is formed only when z ≥ 0.25. A photoluminescence investigation shows, with x increasing the emission spectra of the phosphors (0 ≤ x ≤ 0.45, 0 ≤ y ≤ 0.015, z = 0) obviously red-shift, the corresponding color tones shift from yellow to orange–yellow and their CCTs reduce from 2875 to 2237 K. All the results are beneficial for the phosphors to combining blue light-emitting diode chips to generate warm white light. Besides, the thermal stability of the phosphor (x = 0.36, y = z = 0) is enhanced by doping Ba{sup 2+}, due to the greater activation energy for the compounds containing barium.

• OSTI ID: 22420751
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Vol. 61; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM IONS
CALCIUM IONS
CALCIUM SILICATES
COLOR
EMISSION SPECTRA
EUROPIUM IONS
LIGHT EMITTING DIODES
PHASE STABILITY
PHOSPHORS
PHOTOLUMINESCENCE
RED SHIFT
STRONTIUM SILICATES
THERMODYNAMIC PROPERTIES
VISIBLE RADIATION
X-RAY DIFFRACTION