Synthesis and Luminescent Properties of Dy3+-Activated Yellow Phosphors with Anomalous Thermal Quenching for w-LEDs

Thermal stability is a crucial factor in evaluating phosphors and determining whether they can be utilized in white light emitting diodes (w-LEDs). In this work, a series of Sr6LuAl(BO3)6: Dy3+ (SLAB:Dy3+) phosphors was synthesized via high-temperature solid-state reaction. The synthesized SLAB:Dy3+ phosphor exhibits narrow-band emission in the range of 450–700 nm under 348 nm UV excitation. The strongest emission peak is located at 577 nm and is primarily due to 4F9/2-6H13/2 electron transitions. The optimal doping concentration of Dy3+ in the synthesized phosphor was 15 mol%. The integrated emission intensity of the synthesized phosphor at 480 k is 97.84% of that at 300 k, with excellent thermal stability. The activation energy Eg = 0.62 eV. Meanwhile, the Commission International de l’Eclairage (CIE) coordinates of the prepared w-LEDs were (0.309,0.363) with a correlated color temperature (CCT) of 6497 K. Preliminary experimental findings suggest that SLAB:Dy3+ phosphors hold promise for utilization in w-LEDs applications.