Tailoring cationic configurations in β‐Ca3(PO4)2‐type matrices for gentle orange emission toward eye‐comfort lighting

Abstract Rare‐earth‐doped β‐Ca 3 (PO 4 ) 2 ‐type derivatives are a research hotspot in optoelectronics materials, yet achieving eye‐friendly comfortable emission in such multication lattice systems remains a challenge. Herein, a novel orange‐emitting phosphor Sr 7 LuNaMg 1.5 (PO 4 ) 7 :Eu 2+ was designed based on the crystal structure of Sr 9 Fe 1.5 (PO 4 ) 7 (ICSD No. 93870), whose structure is topologically similar to β‐Ca 3 (PO 4 ) 2 . The title phosphor exhibits ultra‐broadband emission centered at 599 nm (full‐width at half‐maximum = 197 nm) under 395 nm n‐UV excitation. Structural characterization coupled with spectroscopic studies demonstrates the coexistence of multiple luminescent centers in Sr 7 LuNaMg 1.5 (PO 4 ) 7 :Eu 2+ . A progressive redshift in the emission color coordinates was observed with increasing Eu 2+ doping concentrations, attributable to selective cation occupancy and crystal field effects. The concentration‐dependent quenching mechanism was elucidated through comprehensive analysis based on Dexter's theory. Characterization of quantum efficiency, thermal stability and packing density validated the suitability of Sr 7 LuNaMg 1.5 (PO 4 ) 7 :Eu 2+ phosphor for high‐performance white light‐emitting diodes, demonstrating it as a competitive luminescent material for advanced lighting technologies.