Zero-thermal-quenching and charge compensation for efficient luminescence in Ca9ZnK(PO4)7:Sm3+: Optimizing defect engineering

Defect engineering is an effective and fascinating strategy for improving thermostability of phosphor. However, there is the challenge for the diminishment of luminescence intensity, originating from the defect as quenching center. In this work, the defect is introduced through the non-equivalent substitution of Sm3+ for Ca2+, resulting in zero-thermal-quenching (zero-TQ) behavior in Ca9ZnK(PO4)7:0.07Sm3+ (CZKP:0.07Sm3+). Meanwhile, the incorporation of charge compensators (Li+ and Na+) reduces quenching centers and enhances the luminescent performance of the typical CZKP:0.07Sm3+ phosphor, maintaining zero-TQ behavior. Finally, the resulting phosphor are applied to assemble white/red light-emitting diodes (LED) devices, demonstrating highly stable chromatic performance and promising in white/plant growth lighting. This work provides a reference for the effective defect utilization in constructing highly thermostable phosphor.