Highly efficient Ce: Lu(Mg,Al)2(Si,Al)3O12 phosphor ceramics for high-power white LEDs/LDs

Lu3Al5O12: Ce3+ (LuAG: Ce3+) phosphor ceramics (PCs) with high quantum efficiency and excellent thermal stability are incredibly promising color converters for highpower white light emitting diodes (LEDs)/laser diodes (LDs) lighting. However, the greenish emission of LuAG:Ce3+ PCs does not allow to reach white light emission upon pumping by a blue LED/LD without an additional red luminescent material. In this work, a series of (Ce0.003Lu0.997)(3)(MgxAl1-2xSix)(5)O-12 (LCMASG) (x = 0-0.15) PCs were fabricated by solid state reaction method. Impressively, the as-prepared PCs exhibited a distinct red-shift (513.538nm) and a 17% increase of the color index (CRI) of high-power white LED(58.4.70.4). Particularly, Ce: Lu(Mg, Al)(2)(Si, Al)(3)O-12 PC with 15 at.% substitution concentration showed only 8% luminescent intensity loss at 150 degrees C and high internal quantum efficiency (IQE) of 82%, exhibiting desirable optical thermal stability. By combining with a 460 nm blue chip or a 455 nm laser source, white LED/LD devices based on the LCMASG PCs in a remote excitation mode were constructed. The optimized luminous efficiency of Ce: Lu(Mg, Al)(2)(Si, Al)(3)O-12 PC with 15 at.% Mg2+/Si4+ doping up to 176.4 lm/W was obtained as the power density of the blue laser increased to 6.52 W/mm(2). Also, a 4053K CCT of the warm white light emission was realized. Therefore, this work proves that the LCMASG PCs are promising to serve as color converters for high power LEDs/LDs lighting in the future. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

In this study, a series of LCMASG phosphor ceramics were fabricated and successfully achieved white light emission for high-power LEDs/LDs. The prepared phosphor ceramics exhibited excellent stability and high luminescent efficiency at high temperatures, along with red-shift and increased color index, making them suitable for lighting applications.