Synthesis, energy transfer and multicolor luminescent property of Eu3+-doped LiCa2Mg2V3O12 phosphors for warm white light-emitting diodes. Issue 11 (1st August 2019) - Zhou, Jiangcong
Abstract: In this study, Eu 3+ -doped LiCa2 Mg2 V3 O12 (LCMVO) phosphors with multicolor luminescent property were prepared by the solid phase reaction. Their structure, morphology and luminescent property were studied systematically by X-ray diffraction, scanning electron microscope and photoluminescence spectra. The LCMVO phosphors showed pure cubic crystal structure with space group ( I a 3 ¯ d ) and irregular spherical morphology. The excitation spectra showed a strong absorption to ultraviolet light. Under the excitation wavelength at 360 nm, they exhibited a cyan emission with a luminescence center at 520 nm. When Eu 3+ ions were doped into LCMVO system, the Eu 3+ characteristic emissions were also observed and the emission colors were tuned from cyan to orange via adjusting Eu 3+ ion concentration. Further, electric dipole-quadrupole interaction and luminescence decay curves were adopted to explain the energy transfer from (VO4 ) 3- to Eu 3+ . The emission spectra of as-obtained phosphors at different temperature were measured to evaluate their thermal stability. The quantum efficiency values were measured to be 42.5% for LCMVO host and 38.6% for LCMVO: 0.01Eu 3+ sample. The final prepared LED lamp showed easeful warm white light with suitable Ra of 89 and CCT of 3847 K, respectively. These results suggest LCMVO phosphors may be applied in near ultraviolet chip-excited white light-emitting diodes.