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Luminescence characteristics of Sr 1− x Ba x Si 2 O 2 N 2 :Eu 2+ phosphors for white light emitting diodes
Author(s) -
Anoop G.,
Cho I. H.,
Suh D. W.,
Yoo J. S.
Publication year - 2012
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201228128
Subject(s) - phosphor , luminescence , chromaticity , analytical chemistry (journal) , crystal structure , triclinic crystal system , thermal stability , crystallography , materials science , chemistry , physics , optics , optoelectronics , organic chemistry , chromatography
Sr 1− x Ba x Si 2 O 2 N 2 :Eu 2+ phosphors were synthesized using high temperature solid state reaction. The effect of Ba incorporation on the structural and luminescence characteristics of SrSi 2 O 2 N 2 :Eu 2+ phosphors were studied. The phosphors were crystallized in triclinic crystal structure and the cell volume increases monotonically with Ba addition. The PL emission peak wavelength red shifts with Ba up to x = 0.50 beyond which no red shift is observed. The XPS analysis shows that nitrogen is being incorporated into the host lattice along with Ba addition up to x = 0.50. The as synthesized phosphors show high thermal stability. Phosphor converted light emitting diodes were realized using Sr 1− x Ba x Si 2 O 2 N 2 :Eu 2+ phosphors ( x = 0 and x = 0.40) showing luminance efficacies of 108 and 101 lm W −1 .The CIE chromaticity coordinates of Sr 1− x Ba x Si 2 O 2 N 2 :Eu ( x = 0 and x = 0.40) phosphors.