Highly efficient green luminescence from LaF3: Tb3 + glass-ceramic for W-LED application

Recent advances in inorganic luminescent glass-ceramics (GCs) have spurred notable focus in the illumination field owing to their remarkable chemical durability, significant thermal robustness, and efficient thermal conduction. Nonetheless, persistent limitations such as limited luminescence efficiency and suboptimal color rendering have hindered their broader application. In this work, we synthesized Tb³⁺-activated oxyfluoride GCs embedded with LaF₃ crystal through melt-quenching followed by controlled thermal processing. Upon compositional and process optimization, the GC containing 1.0 mol% Tb₄O₇ demonstrated pronounced green emission centered at 544 nm under 376 nm excitation, achieving an exceptional internal quantum efficiency (IQE) of 90.55 %. Furthermore, this material retained 92 % of its original emission intensity at an elevated temperature of 150 °C, highlighting its excellent thermal stability and resistance to fluorescence quenching. To evaluate practical applicability, the optimized GC was utilized alongside a 370 nm UV-LED and commercial phosphors to assemble a W-LED prototype. The resultant prototype exhibited warm white light featuring a correlated color temperature (CCT) of 4116 K as well as a high color rendering index (CRI) of 92, underscoring the material's potential for advanced solid-state lighting applications.