A single-phased warm white-light-emitting phosphor BaMg2(PO4)2:Eu2+, Mn2+, Tb3+ for white light emitting diodes

• Eu2+, Tb3+ and Mn2+ doped BaMg2(PO4)2 emits blue, green and red light, respectively.
• Energy transfer from Eu2+ to Tb3+ and Mn2+ in BaMg2(PO4)2 occurs.
• BaMg2(PO4)2:Eu2+, Mn2+, Tb3+ can emit warm white light.

A single-phase white-emitting phosphor BaMg2(PO4)2:Eu2+, Mn2+, Tb3+ is synthesized by a high temperature solid-state reaction. The luminescent properties and the efficient energy transfer from Eu2+ to Mn2+ and Tb3+ in BaMg2(PO4)2 are investigated. The chromaticity coordinates of BaMg2(PO4)2:Eu2+, Mn2+, Tb3+ can be tuned from (0.153, 0.056) (for BaMg2(PO4)2:Eu2+) to (0.666, 0.261) (for BaMg2(PO4)2:Mn2+), and eventually to (0.313, 0.562) (for BaMg2(PO4)2:Tb3+) by the effective resonance type energy transfer. The warm white light can be realized with the superior chromaticity coordinates of (0.346, 0.299) and low correlated color temperature (CCT = 4464 K) by coupling the emission bands peaking at 447, 544 and 663 nm attributed to the contribution from Eu2+, Tb3+ and Mn2+, respectively.

A series of single-phased novel color-tunable BaMg2(PO4)2:Eu2+, Mn2+, Tb3+ phosphors have been synthesized and the luminescence properties as well as energy transfer from different Eu2+ sites to Mn2+ and to Tb3+ are investigated in detail. The emission color of BaMg2(PO4)2:3%Eu2+, y%Mn2+, z%Tb3+ phosphors can be tuned from blue to green or red based on the effective energy transfer. More importantly, white LEDs with CCT = 4464 K and CIE = (0.346, 0.299) that are close to the ideal warm white light is realized by pumping BaMg2(PO4)2:3%Eu2+, 3%Mn2+, 3%Tb3+ with a 365 nm UV-chip. Our results indicate that BaMg2(PO4)2:Ce3+, Mn2+, Tb3+ may be a potential single-phase white-emitting phosphor for white LEDs.Figure optionsDownload as PowerPoint slide