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Title: 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

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,more » y = z = 0) is enhanced by doping Ba{sup 2+}, due to the greater activation energy for the compounds containing barium.« less
Authors:
 [1] ;  [2] ;  [1] ;  [2] ;  [3]
  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)
Publication Date:
OSTI Identifier:
22420751
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 61; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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