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The fabrication and luminescent performance of novel phosphors Na 2 YMg 2 V 3 O 12 :Dy 3+ were investigated by a conventional solid-state reaction method. Under near-UV light, the Na 2 YMg 2 V 3 O 12 host self-activated and released a broad emission band (400-700 nm, with a peak at 524 nm) ascribable to charge transfer in the (VO 4 ) 3- groups. Meanwhile, the Na 2 YMg 2 V 3 O 12 :Dy 3+ phosphors emitted bright yellow light within both the broad emission band of the (VO 4 ) 3- groups and the sharp peaks of the Dy 3+ ions at 490, 582, and 663 nm at a quenching concentration of 0.03 mol. The emission of the as-prepared Na 2 YMg 2 V 3 O 12 :Dy 3+ phosphors remained stable at high temperatures. The obtained phosphors, commercial Y 2 O 3 :Eu 3+ red phosphors, and BaMgAl 10 O 17 :Eu 2+ blue phosphors were packed into a white light-emitting diode (WLED) device with a near-UV chip. The designed WLED emitted bright white light with good chromaticity coordinates (0.331, 0.361), satisfactory color rendering index (80.2), and proper correlation to a color temperature (7364 K). These results indicate the potential utility of Na 2 YMg 2 V 3 O 12 :Dy 3+ phosphor as a yellow-emitting phosphor in solid-state illumination.

The development of white-light-emitting diodes (w-LEDs) makes it meaningful to develop novel high-performance phosphors excited by blue light. Herein, BiOCl:Pr 3+ green-yellow phosphors were prepared via a high-temperature solid-state reaction method. The crystal structure, luminescent properties, lifetime, thermal quenching behavior, and quantum yield were studied in detail. The BiOCl:Pr 3+ phosphors presented several emission peaks located in green and red regions, under excitation at 453 nm. The CIE coordinates could be tuned along with the changed doping concentration with fair luminescence efficiency. The results also indicated that the optimized doping concentration of Pr 3+ ions was at x = 0.0075 because of the concentration quenching behavior resulting from an intense exchange effect. When the temperature reached 150 °C, the intensity of the emission peak at 495 nm could remain at 78% of that at room temperature. The activation energy of 0.20 eV also confirmed that the BiOCl:Pr 3+ phosphor exhibited good thermal stability. All these results indicate that the prepared products have potential to be used as a high-performance green-yellow-light-emitting phosphor for blue-light-based w-LEDs.

Advances in solid-state white-light-emitting diodes (WLEDs) necessitate the urgent development of highly efficient single-phase phosphors with tunable photoluminescence properties. Herein, the Tm3+, Dy3+, and Sm3+ ions are incorporated into the orthorhombic NaGdTiO4 (NGT) phosphors, resulting in phosphors that fulfill the aforementioned requirement. The emission spectrum of Tm3+ ions overlaps well with the adsorption spectra of both Dy3+ and Sm3+ ions. Under the excitation at 358 nm, the single-phase NaGdTiO4: Tm3+, Dy3+, Sm3+ phosphor exhibits tunable emission peaks in the blue, yellow, and red regions simultaneously, resulting in an intense white-light emission. The coexisting energy transfer behaviors from Tm3+ to Dy3+ and Sm3+ ions and the energy transfer from Dy3+ to Sm3+ ions are demonstrated to be responsible for this phenomenon. The phosphors with multiple energy transfers enable the development of single-phase white-light-emitting phosphors for phosphor-converted WLEDs. [ABSTRACT FROM AUTHOR]

The fabrication and luminescent performance of novel phosphors Na2YMg2V3O12:Dy3+ were investigated by a conventional solid-state reaction method. Under near-UV light, the Na2YMg2V3O12 host self-activated and released a broad emission band (400–700 nm, with a peak at 524 nm) ascribable to charge transfer in the (VO4)3− groups. Meanwhile, the Na2YMg2V3O12:Dy3+ phosphors emitted bright yellow light within both the broad emission band of the (VO4)3- groups and the sharp peaks of the Dy3+ ions at 490, 582, and 663 nm at a quenching concentration of 0.03 mol. The emission of the as-prepared Na2YMg2V3O12:Dy3+ phosphors remained stable at high temperatures. The obtained phosphors, commercial Y2O3:Eu3+ red phosphors, and BaMgAl10O17:Eu2+ blue phosphors were packed into a white light-emitting diode (WLED) device with a near-UV chip. The designed WLED emitted bright white light with good chromaticity coordinates (0.331, 0.361), satisfactory color rendering index (80.2), and proper correlation to a color temperature (7364 K). These results indicate the potential utility of Na2YMg2V3O12:Dy3+ phosphor as a yellow-emitting phosphor in solid-state illumination. [ABSTRACT FROM AUTHOR]