TY - JOUR
T1 - Temperature dependence of Ce:YAG single-crystal phosphors for high-brightness white LEDs/LDs
AU - Arjoca, Stelian
AU - Víllora, Encarnación G.
AU - Inomata, Daisuke
AU - Aoki, Kazuo
AU - Sugahara, Yoshiyuki
AU - Shimamura, Kiyoshi
N1 - Funding Information:
The authors are in debt to Mr Junichi Hayashi from Shinko Manufacturing Co., Ltd. for his continuous support with crystal growth experiments. This work was partially supported by JSPS KAKENHI Grant Number 25420308.
Publisher Copyright:
© 2015 IOP Publishing Ltd.
PY - 2015/5
Y1 - 2015/5
N2 - The growth of Ce:Y3Al5O12(Ce:YAG) single-crystal phosphors (SCPs) by the Czochralski technique is analyzed in terms of segregation coefficient, solubility and absorption cross-section. The emission characteristics of these SCPs are investigated in a wide temperature range, from liquid He temperature up to 500 °C. The internal quantum efficiency of SCPs achieves its maximum at about 250 °C. Thermal quenching of SCPs at high temperature is attributed to the Mott-Seitz mechanism. In the case of ceramic powder phosphors, a continuous droop is observed with the temperature due to defectrelated non-radiative recombination paths. It is shown that (Ce:YAG SCPs + blue LEDs/LDs) can cover a wide range of color temperatures 5500-7000 K, with color rendering indices around 70. In conclusion, it is shown that Ce:YAG SCPs are the most efficient and temperature stable converters to fabricate high-brightness white light sources with high-power blue LEDs and LDs.
AB - The growth of Ce:Y3Al5O12(Ce:YAG) single-crystal phosphors (SCPs) by the Czochralski technique is analyzed in terms of segregation coefficient, solubility and absorption cross-section. The emission characteristics of these SCPs are investigated in a wide temperature range, from liquid He temperature up to 500 °C. The internal quantum efficiency of SCPs achieves its maximum at about 250 °C. Thermal quenching of SCPs at high temperature is attributed to the Mott-Seitz mechanism. In the case of ceramic powder phosphors, a continuous droop is observed with the temperature due to defectrelated non-radiative recombination paths. It is shown that (Ce:YAG SCPs + blue LEDs/LDs) can cover a wide range of color temperatures 5500-7000 K, with color rendering indices around 70. In conclusion, it is shown that Ce:YAG SCPs are the most efficient and temperature stable converters to fabricate high-brightness white light sources with high-power blue LEDs and LDs.
KW - Ce-doped garnets
KW - Quantum efficiency
KW - Single-crystal phosphors
KW - White LEDs/LDs
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U2 - 10.1088/2053-1591/2/5/055503
DO - 10.1088/2053-1591/2/5/055503
M3 - Article
AN - SCOPUS:84953438981
SN - 2053-1591
VL - 2
JO - Materials Research Express
JF - Materials Research Express
IS - 5
M1 - 055503
ER -