Thermally Robust and Color-Tunable Blue-Green-Emitting BaMgSiO:Eu,Mn Phosphor for Warm-White LEDs.

The dual emission produced from Mn when codoped with rare earth ions like Eu or Ce 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 BaMgSiO:Eu,Mn phosphors with thermally robust, tunable luminescence are reported. Steady-state and time-resolved photoluminescence spectroscopy reveal that Eu and Mn each occupy a single crystallographic site and confirm that energy transfer occurs from Eu to Mn. The internal and external quantum efficiency of BaMgSiO:Eu,Mn 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 BaMgSiO:Eu,Mn and the red-emitting SrSiN:Eu phosphors exhibits an excellent CRI of 94.3 with a correlated color temperature of 3967 K. These results prove the potential applications of Eu,Mn codoped BaMgSiO phosphor for generating warm-white light.