Synthesis and photoluminescent mechanisms of Ce3+-Activated KSr6ScSi4O16 blue-emitting phosphors for advanced solid-state lighting

The KSr 6 ScSi 4 O 16 :Ce 3+ phosphor exhibits a blue emission with a main peak at 407 nm. • It retains 95.53% of the room-temperature luminescence at 420 K. • It has a high color purity of 97.3% and remarkable chromaticity coordinate stability. • The w-LED exhibits a high CRI value of 92 and a good CCT of 5148 K. In the pursuit of next-generation solid-state lighting that prioritizes high color rendering indices and tunable correlated color temperatures, developing thermally robust blue-emitting phosphors excitable by near-ultraviolet radiation is a key challenge. In this work, the high luminous thermal stability blue light emission activated by Ce 3+ in the KSr6ScSi4O16 matrix is reported for the first time. X-ray diffraction confirms a pure-phase solid. Ce 3+ ions preferentially occupy the lattice sites of Sr 2+ and the shared [K + /Sr 2+ ] positions within the KSr 6 ScSi 4 O 16 structure. Under 350 nm n-UV excitation, it exhibits intense broad-band blue emission peaking at 407 nm, attributed to spin-orbit-split 5d-4 f electronic transitions. Detailed investigation into the concentration quenching kinetics reveals an optimal doping concentration of 5 mol%, with the quenching mechanism governed principally by nearest-neighbor ion interactions. It retains 95.53% of its intensity at 420 K, with a high activation energy of 0.28 eV. Color purity reaches 97.3% with stable chromaticity coordinates. The bright WLEDs fabricated on a 370 nm chip demonstrate excellent white-light performance, with a correlated color temperature of 5148 K and a high color rendering index of 92, underscoring the practical viability of this newly developed phosphor.