Color-tunable luminescence in KBaPO4:Sm/Eu phosphors for white-light emission

초록

KBaPO4:Sm/Eu phosphors with an ABPO(4)-type framework were synthesized via combustion synthesis to investigate simultaneous blue and red luminescence within a single host lattice. X-ray diffraction confirmed phase purity and successful crystallization. Under similar to 401 nm excitation, hydrogen-annealed samples exhibited broadband blue emission from the allowed 4f(6)5 d(1) -> 4f(7) transition of Eu2+, together with characteristic Sm3+ red emissions arising from the (4)G(5/2) -> H-6(J) transitions. The relative emission intensities were tuned by controlling Eu2+ concentration and annealing conditions, enabling color tuning toward white-light emission suitable for W-LED applications. Luminescence lifetimes were similar to 440 ns for Eu2+ and similar to 2.5 ms for Sm3+. Photoluminescence quantum-yield analysis yielded an external quantum efficiency of similar to 48% and an internal quantum efficiency of similar to 66%, indicating efficient radiative recombination. These results demonstrate that KBaPO4:Sm/Eu is a promising color-tunable phosphor for solid-state lighting and potential security-related optical applications.

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