A novel red phosphor Ba2La4Y4(SiO4)6O2:Eu3+ with high quantum yield and thermal stability for warm white LEDs

A novel silicate oxyapatite red phosphor Ba2La4Y4(SiO4)(6)O-2:Eu3+ was synthesized by solid state reaction method. The results show that Eu3+ ions replace La3+ ions can lead to higher luminescence intensity than replacing Y3+ ions. Moreover, Ba2La4Y4(SiO4)(6)O-2:Eu3+ shows a high quantum yield of 67.46% and high thermal stability (the luminescence intensity remains 94.1% of its initial PL intensity at 125 degrees C, and maintains 77.6% at 150 degrees C) by regulating the relative content of Y3+ ions and La3+ ions. Finally, a warm white LED with low CCT of 3306 K, high luminous efficiency of 33.55 lm/W and Ra of 91 was achieved by combining Ba2Y4La4(SiO4)(6)O-2:Eu3+ red phosphor with BaMgAl10O17:Eu2+ blue phosphor and (Sr, Ba)(2)SiO4:Eu2+ green phosphor under 395 nm NUV chips. All the results manifest that the red phosphor Ba2Y4La4(SiO4)(6)O-2:Eu3+ can be used as a potential NUV-excited red phosphor for high-performance high-power warm white LEDs. (C) 2019 Elsevier B.V. All rights reserved.