Synthesis and luminescence properties of (Dy3+, Eu3+) ions co-doped double-perovskite Ba2LaNbO6 phosphors

Dy3+ and Eu3+ ions co-doped double-perovskite Ba2LaNbO6 phosphor was prepared by a high-temperature solid-state reaction method. The effects of ions co-doping concentration onto the crystal structures, surface morphologies and photoluminescence properties of phosphors were elucidated by using X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), and fluorescence spectrophotometer, respectively. The XRD patterns reveal that the crystallization of Dy3+ and Eu3+ ions co-doped Ba2LaNbO6 was monoclinic phase with space group of C2/m. For the Dy3+ ion-doped Ba2LaNbO6 phosphors under an excitation wavelength of 293 nm, the main emission wavelengths are between 460 and 520 nm and 560 and 620 nm, which are due to the F-4(9/2) -> H-6(15/2) magnetic dipole transition and the F-4(9/2)-> H-6(13/2) super sensitive transition of Dy3+ ion, respectively. The concentration quenching effect occurs as the Dy3+ ion concentration is 4 mol%. The CIE chromaticity coordinates shift from the light blue region to the green region as the Dy3+ ion doping concentration increases. When the Dy3+ and Eu3+ ions co-doped Ba2LaNbO6 phosphors, the CIE chromaticity coordinates of Ba-2(La-0.9575 Dy0.04Eu0.0025)NbO6 phosphors are moved from the green light region to the near white-light region due to the mixing of the strong magnetic dipole transition of D-5(0) -> F-7(1) at 594 nm, and electric dipole transition of( 5)D(0) -> F-7(2) at 617 nm for the characteristic f-f transition of Eu3+ ion.