Synthesis and photoluminescence properties of Eu3+-doped Na2YMg2V3O12: A novel red-emitting phosphor for WLEDs.

Na 2 YMg 2 V 3 O 12 :Eu3+ phosphors were obtained by co-doping with Eu3+ ions and a LED lamp including the obtained phosphors was designed and packaged. To balance the colour combination and improve the Ra value of the LED, small quantities of commercial (Ba, Sr) 2 SiO 4 :Eu2+ green phosphor and BaMgAl 10 O 17 :Eu2+ blue phosphor were added. The LED device emitted light changed from red to white, with CIE coordinates of (0.3068, 0.3491). These results demonstrate that the as-prepared phosphors are promising red-emitting phosphors for indoor solid-state illumination. [Display omitted] The fabrication and luminescent properties of novel Na 2 YMg 2 V 3 O 12 :Eu3+ phosphors, obtained by a conventional solid-state reaction, were investigated. The self-activated emission of the Na 2 YMg 2 V 3 O 12 host exhibits a broad emission band ranging from 400 to 700 nm with a maximum peak at 530 nm, ascribed to the d-d transition (3T 2 , 3T 1 → 1A 1) of V5+ ions in the (VO 4)3− groups. On excitation with near-UV (365 nm) light, the Na 2 YMg 2 V 3 O 12 :Eu3+ phosphors emit bright red light, including both the broad emission band of the (VO 4)3− groups and the sharp emission peaks of Eu3+ ions. At a quenching concentration of 0.20 mol, the Eu3+ ion emission peaks were located at 597, 613, 654 and 710 nm. The thermal stability of the as-prepared Na 2 YMg 2 V 3 O 12 :Eu3+ phosphor was studied and the thermal quenching activation energy (△ E) was calculated to be 0.33 eV. Furthermore, a designed and packaged white-light-emitting diode (WLED) lamp, fabricated with the obtained phosphors, commercial (Ba, Sr) 2 SiO 4 :Eu2+ green phosphors, BaMgAl 10 O 17 :Eu2+ blue phosphors and a near-ultraviolet (n -UV) chip, emitted bright white light with a CIE coordinate of (0.3068, 0.3491), CRI of 88.20 and CCT of 4460 K. These results indicate the potential of the as-prepared Na 2 YMg 2 V 3 O 12 :Eu3+ phosphor as a red-emitting phosphor for solid-state illumination. [ABSTRACT FROM AUTHOR]