TY - JOUR
T1 - Unusual, broad red emission of novel Ce3+-activated Sr3Sc4O9 phosphors under visible-light excitation
AU - Hasegawa, Takuya
AU - Kim, Sun Woog
AU - Ueda, Tadaharu
AU - Ishigaki, Tadashi
AU - Uematsu, Kazuyoshi
AU - Takaba, Hiromitsu
AU - Toda, Kenji
AU - Sato, Mineo
PY - 2017
Y1 - 2017
N2 - Most conventional white light emitting diodes (white-LEDs) that are widely used as a new lighting system in next generation lights with Y3Al5O12:Ce3+ (YAG:Ce3+)-based phosphors have a low colour rendering index (CRI) because the YAG:Ce3+ phosphor shows a weak emission intensity in the red spectral region. Therefore, discovering a red-emitting phosphor with a high-efficiency is quite important to enhance the CRI of white-LEDs. In this study, we successfully discovered a novel, red-emitting Ce3+-activated Sr3Sc4O9 phosphor that can be excited by blue-light irradiation at 425 nm. A crystal structure of the host material was first determined by Rietveld refinement, which indicated that it should be isostructural with Ba3Ln4O9 (Ln = Sc, Y and Dy-Lu). As the Ce3+ content increased, the X-ray diffraction patterns shifted to a lower angle, which suggested that the Ce3+ ion could substitute Sc in the Sr3Sc4O9 host. Under UV and blue-light excitation, the Ce3+-activated Sr3Sc4O9 phosphor exhibited a broad emission band with a maximum peak at 620 nm, and its full width half maximum (FWHM) was 180 nm (4530 cm-1). The highest emission intensity was obtained for Sr3(Sc0.997Ce0.003)4O9, and the internal quantum efficiency of this phosphor under excitation at 425 nm was 53%. To the best of our knowledge, the emission band of the Ce3+-activated Sr3Sc4O9 phosphor is the longest wavelength for a reported Ce3+-activated oxide phosphor.
AB - Most conventional white light emitting diodes (white-LEDs) that are widely used as a new lighting system in next generation lights with Y3Al5O12:Ce3+ (YAG:Ce3+)-based phosphors have a low colour rendering index (CRI) because the YAG:Ce3+ phosphor shows a weak emission intensity in the red spectral region. Therefore, discovering a red-emitting phosphor with a high-efficiency is quite important to enhance the CRI of white-LEDs. In this study, we successfully discovered a novel, red-emitting Ce3+-activated Sr3Sc4O9 phosphor that can be excited by blue-light irradiation at 425 nm. A crystal structure of the host material was first determined by Rietveld refinement, which indicated that it should be isostructural with Ba3Ln4O9 (Ln = Sc, Y and Dy-Lu). As the Ce3+ content increased, the X-ray diffraction patterns shifted to a lower angle, which suggested that the Ce3+ ion could substitute Sc in the Sr3Sc4O9 host. Under UV and blue-light excitation, the Ce3+-activated Sr3Sc4O9 phosphor exhibited a broad emission band with a maximum peak at 620 nm, and its full width half maximum (FWHM) was 180 nm (4530 cm-1). The highest emission intensity was obtained for Sr3(Sc0.997Ce0.003)4O9, and the internal quantum efficiency of this phosphor under excitation at 425 nm was 53%. To the best of our knowledge, the emission band of the Ce3+-activated Sr3Sc4O9 phosphor is the longest wavelength for a reported Ce3+-activated oxide phosphor.
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U2 - 10.1039/c7tc03203j
DO - 10.1039/c7tc03203j
M3 - Article
AN - SCOPUS:85029882979
VL - 5
SP - 9472
EP - 9478
JO - Journal of Materials Chemistry C
JF - Journal of Materials Chemistry C
SN - 2050-7526
IS - 36
ER -