Eu2+-activated Sr8ZnSc(PO4)7: A novel near-ultraviolet converting yellow-emitting phosphor for white light-emitting diodes

Chien Hao Huang*, Yi Chen Chiu, Yao Tsung Yeh, Ting Shan Chan, Teng-Ming Chen

*Corresponding author for this work

Research output: Contribution to journalArticle

111 Scopus citations

Abstract

The crystal structure of Eu2+-activated Sr 8ZnSc(PO4)7:Eu2+ phosphor was refined and determined from XRD profiles by the Rietveld refinement method using a synchrotron light source. This phosphor crystallizes in the monoclinic structure with the I2/a space group. The SZSP:xEu2+ phosphors showed a broad yellow emission band centered at 511 and 571 nm depending on the concentration of Eu2+, and the composition-optimized concentration of Eu2+ in the Sr8ZnSc(PO4)7:Eu 2+ phosphor was determined to be 2 mol %. The estimated crystal-field splitting and CIE chromaticity coordinates of Sr8ZnSc(PO 4)7:xEu2+ (x = 0.001-0.05 mol) were 20181-20983 cm-1 and (0.3835, 0.5074) to (0.4221, 0.5012), respectively, and the emission band showed a redshift from 547 to 571 nm with increasing Eu 2+ concentration. The nonradiative transitions between the Eu 2+ ions in the Sr8ZnSc(PO4)7 host were attributable to dipole-dipole interactions, and the critical distance was approximately 19.8 Å. The combination of a 400 nm NUV chip with a blend of Sr8ZnSc(PO4)7:0.02Eu2+ and BAM:Eu2+ phosphors (light converters) gave high color rendering indices between 79.38 and 92.88, correlated color temperatures between 4325 and 7937 K, and tuned CIE chromaticity coordinates in the range (0.381, 0.435) to (0.294, 0.310), respectively, depending on the SZSP:0.02Eu2+/BAM: Eu2+ weight ratio. These results suggest that the Sr 8ZnSc(PO4)7:0.02Eu2+/BAM:Eu 2+ phosphor blend has potential applications in white NUV LEDs.

Original languageEnglish
Pages (from-to)6661-6668
Number of pages8
JournalACS Applied Materials and Interfaces
Volume4
Issue number12
DOIs
StatePublished - 26 Dec 2012

Keywords

  • Eu
  • NUV
  • photoluminescence
  • SrZnSc(PO)
  • white LED
  • yellow-emitting

Fingerprint Dive into the research topics of 'Eu<sup>2+</sup>-activated Sr<sub>8</sub>ZnSc(PO<sub>4</sub>)<sub>7</sub>: A novel near-ultraviolet converting yellow-emitting phosphor for white light-emitting diodes'. Together they form a unique fingerprint.

  • Cite this