A Novel Cyan-Emitting Ca2LuZr2Al1.5Ga1.5O12:Ce3+ Phosphor Excited by Violet Light toward Full-Spectrum White LEDs

The development of full-spectrum white LEDs is significantly hindered by the “cyan gap” in the 470-510 nm spectral region. Addressing this gap with moderate -quality cyan-emitting phosphors, efficiently excited by violet LED chips, is crucial for achieving high color rendering index (Ra > 90) illumination. In this study, a novel and moderate efficient garnet-structured cyan-emitting phosphor Ca 2 LuZr 2 Al 1.5 Ga 1.5 O 12 :Ce 3+ (CLZAGO:Ce 3+ ) was effectively prepared via a high-temperature solid-state reaction route. When excited at 410 nm, the optimized CLZAGO:0.04Ce 3+ sample displays a robust cyan emission peaking at 484 nm, accompanied by a broad emission band spanning 420-650 nm and a full width at half-maximum (FWHM) of 90 nm, which efficiently fills the cyan gap commonly observed in conventional White light-emitting diodes (WLEDs). The phosphor exhibits available thermal stability, preserving 53% of its room-temperature emission intensity at 423 K, and achieves a moderate external quantum efficiency (EQE) of 45.43%. Finally, when CLZAGO:Ce 3+ was combined with commercial blue-emitting Sr 5 (PO 4 ) 3 Cl:Eu 2+ (SPOC:Eu 2+ ), green-emitting (Ba, Sr) 2 SiO 4 :Eu 2+ (BSSO:Eu 2+ ), and red-emitting CaAlSiN 3 :Eu 2+ (CASN:Eu 2+ ) phosphors and integrated into a 410 nm violet LED chip, a full-spectrum WLED with an enhanced Ra of 95 was achieved. These findings underscore the critical role of CLZAGO:Ce 3+ as a promising cyan-emitting component for next-generation high color-rendering full-spectrum WLEDs.