Translucent YAG:Ce-SiO₂ Composites Prepared by Pressureless Sintering: Structures, Luminescence Properties, and Applications in the White LEDs/LDs

Phosphor–glass composites are popular color converters used in white light-emitting diodes (LEDs) and white laser diodes (LDs) due to diverse phosphors and glass compositions. Herein, commercial phosphors are evenly embedded in the silica glass matrix through cold isostatic pressing and low-temperature pressureless sintering, enabling cost-effective and mass production of phosphor–glass composites. The YAG:Ce-SiO2 samples exhibit considerable transmittance (above 44% at 600 nm, 1.0 mm in thickness), uniform phosphor particle distribution, and excellent internal quantum efficiency of above 90%. The YAG:Ce-SiO2-based LED device emits near-standard white light with a luminous efficiency (LE) of 130.7 lm/W, correlated color temperature (CCT) of 5501 K, and color rendering index (Ra) of 75.2, and the corresponding reflection-type white LD device exhibits an LE of 204.5 lm/W, CCT of 5548 K, and Ra of 68.7. It indicates that these translucent YAG:Ce-SiO2 composites exhibit great promise in high-power lighting devices.