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

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.