NaAlSiO4: Eu2+ Glass Ceramics: Self-Reduced In Situ Growth and High-Power LED/LD Lighting

Currently, exploiting luminescent materials with super thermal stability and high luminous efficiency are highly urgent to meet the needs of fast developing high-power solid-state lighting (SSL). Glass ceramic (GC) bulk material is an optimal medium with rigid glass network structure and controllable glass crystallization. Herein, an in situ glass crystallization strategy combined with self-reduced Eu2+ is developed to fabricate Eu2+ doped NaAlSiO4 (NASO) GC composites in air. Structural and spectroscopic characterizations verify that the in situ precipitated NASO nanocrystals with high crystallization density can accommodate Eu2+ emitting centers in the same glass region, which facilitates the separation of Eu2+ dopants from glass into crystalline lattice without the requirement of long-distance ionic diffusion and provides strong crystal-field environment for Eu2+ 5d-4f transition. Particularly, the present composites can produce intense greenish-yellow emission with apparent photoluminescence quantum yield (PLQY) of approximate to 70%, intrinsic PLQY of approximate to 100%, superior thermal stability with 90% PL remained at 150 degrees C and excellent water-resistance. Employing NSAO: Eu2+ GC as a color converter, the performance of constructed light-emitting diode (LED)/laser diode (LD) lighting devices is extraordinary and stable during long-term working. These findings would expand the application of GC composites and open up new avenues for exploration of novel GC materials and glass crystallization strategies.