Thermally Robust and Color-Tunable Blue-Green-Emitting BaMgSi₄O₁₀:Eu²⁺,Mn²⁺ Phosphor for Warm-White LEDs

Abstract

The dual emission produced from Mn²⁺ when codoped with rare earth ions like Eu²⁺ or Ce³⁺ in inorganic compounds makes these materials attractive as efficient, color-tunable phosphors for warm-white solid-state lighting. Here, a series of efficient blue-green-emitting BaMgSi₄O₁₀:Eu²⁺,Mn²⁺ phosphors with thermally robust, tunable luminescence are reported. Steady-state and time-resolved photoluminescence spectroscopy reveal that Eu²⁺ and Mn²⁺ each occupy a single crystallographic site and confirm that energy transfer occurs from Eu²⁺ to Mn²⁺. The internal and external quantum efficiency of BaMgSi₄O₁₀:Eu²⁺,Mn²⁺ can reach as high as 69.0 and 47.5%, respectively, upon 360 nm excitation. Moreover, this phosphor possesses nearly zero-thermal quenching up to 440 K due to thermally induced electron detrapping. A fabricated UV-excited white LED device incorporating the blue-green-emitting BaMgSi₄O₁₀:Eu²⁺,Mn²⁺ and the red-emitting Sr₂Si₅N₈:Eu²⁺ phosphors exhibits an excellent CRI of 94.3 with a correlated color temperature of 3967 K. These results prove the potential applications of Eu²⁺,Mn²⁺ codoped BaMgSi₄O₁₀ phosphor for generating warm-white light.