Realizing multicolor tunable photoluminescence in La2MgTiO6: Tb3+, Eu3+ phosphors via energy transfer and application for white light-emitting diodes

The achievement of multiple emission color phosphors has a significant importance in screen display, lighting devices, and multicolor imaging, but it still faces formidable challenges. In this work, double perovskite La ₂MgTiO ₆: Tb ³⁺, Eu ³⁺ phosphors with tunable emissions are designed and successfully synthesized. The obtained phosphors can emit intense green (Tb ³⁺), red (Eu ³⁺), and yellow emissions (Tb ³⁺/Eu ³⁺) via varying the co-doping concentration of Tb ³⁺ and Eu ³⁺. The CIE coordinates exhibit an excellent linear behavior in La ₂MgTiO ₆: Tb ³⁺, Eu ³⁺, revealing the possibility of linear adjustment of multiple emission colors. Detailed material characterization demonstrates that the multicolor tunable emission originates from energy transfer between Tb ³⁺ and Eu ³⁺. The decay dynamics analysis suggests that the multipole interaction between Tb ³⁺ and Eu ³⁺ is quadrupole-quadrupole interaction. A white light-emitting diode device with color rendering index of 84.7, correlated color temperature of 4684 K, and CIE coordinate of (0.3472, 0.3083) is fabricated by combining La ₂MgTiO ₆: Tb ³⁺, Eu ³⁺ yellow phosphor and BaMgAl ₁₀O ₁₇: Eu ²⁺ blue phosphor. Our results reveal that La ₂MgTiO ₆: Tb ³⁺, Eu ³⁺ phosphors are promising luminescent materials in white light-emitting diodes.