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

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.