High-Quantum-Efficiency Blue Phosphors with Superior Thermal Stability Derived from Eu³⁺-Doped Faujasite Y Zeolite

Blue phosphors of high efficiency and superior thermal stability constitute the critical component for achieving high-quality white light-emitting diodes (WLEDs). Herein, we report a highly efficient blue-emitting phosphor with superior thermal stability by heating Eu³⁺-doped Faujasite Y zeolite under a reducing atmosphere. The intensity and peak value of the phosphor are highly dependent on calcination temperature, and the intensity of PLE and PL spectra reaches a maximum at 1100 °C. Under the excitation of 360 nm, the phosphor shows a high quantum efficiency (90%) and thermal stability (the emission intensity at 423 K is about 125% of that at room temperature). WLEDs fabricated using this blue phosphor, a yellow Eu²⁺-SOD phosphor, and a commercially available red Sr₂Si₅N₈:Eu²⁺ phosphor exhibit an excellent optical performance with a correlated color temperature of 4359 K and a color rendering index of 97. This work provides a new strategy for the synthesis of phosphors with high thermal stability and luminous efficiency.