Energy migration (energy transfer among identical luminescence centers) is always thought to be related to the concentration quenching in luminescence materials. However, the novel Eu 3+ -doped Ba 6 Gd 2 Ti 4 O 17 phosphor seems to be an exception. In the series of Ba 6 Gd 2(1−x) Ti 4 O 17 :xEu 3+ (x = 0.1, 0.3, 0.5, 0.7, and 0.9) phosphors prepared and investigated, no concentration quenching is found. Detailed investigations of the crystal structure and the luminescence properties of Ba 6 Gd 2(1−x) Ti 4 O 17 :xEu 3+ reveal that the nonoccurrence of concentration quenching is related to the dimensional restriction of energy migration inside the crystal lattices. In Ba 6 Gd 2 Ti 4 O 17 , directly increasing the number of Eu 3+ ions to absorb as much excitation energy as possible allows to achieve a higher brightness. The highly Eu 3+ -doped Ba 6 Gd 2(1−x) Ti 4 O 17 :xEu 3+ (x = 0.9) sample can convert near-UV excitation into red light, whose Commission Internationale de l'Eclairage (CIE) coordinates are (0.64, 0.36) and the color purity can reach up to 94.4%. Moreover, warm white light with the CIE chromaticity coordinates of (0.39, 0.39), the correlated color temperature of 3756 K, and the color rendering index of 82.2 is successfully generated by fabricating this highly Eu 3+ -doped phosphor in a near-UV light-emitting diode chip together with the green YGAB:Tb 3+ and blue BAM:Eu 2+ phosphors. KEYWORDS: Eu 3+ -doped phosphor, Ba 6 Gd 2 Ti 4 O 17 host, nonconcentration quenching, energy migration, light-emitting diodes

Eu ion can be effectively sensitized by Ce ion through an energy-transfer chain of Ce-(Tb) -Eu, which has contributed to the development of white light-emitting diodes (WLEDs) as it can favor more efficient red phosphors. However, simply serving for WLEDs as one of the multicomponents, the design of the Ce-(Tb) -Eu energy transfer is undoubtedly underused. Theoretically, white light can be achieved with extra blue and green emissions released from Ce and Tb. Herein, the design of the white light based on these three multicolor luminescence centers has been realized in GdBO. It is the first time that white light is generated via accurate controls on the Ce-(Tb) -Eu energy transfer in such a widely studied host material. Because the thermal quenching rates of blue, green, and red emissions from Ce, Tb, and Eu, respectively, are well-matched in the host, this novel white light exhibits superior color stability and potential application prospect.

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MgF2 assisted delicate synthesis and application of a bright and moisture-resistant LAG:Mn4+,Mg2+ phosphor.

Energy-transfer-based multi-colour emissions in YGa1.5Al1.5(BO3)4:Tb3+,Eu3+ for WLEDs.