Effect of substituting Y³⁺/W⁶⁺/F⁻ ions on the luminescent properties of novel red-emitting NaMg₃In(MoO₄)₅: Eu³⁺ phosphors for white LED

To achieving high-quality white light emitting diodes (LED), a series of novel red-emitting phosphors NaMg₃In_1-zY_z(Mo_1-yW_yO_4-xF_x)₅: 0.10Eu³⁺ (x = 0–0.20, y = 0–0.05, z = 0–0.20) have been obtained via solid-state reaction process. The luminescent properties of NaMg₃In(MoO₄)₅: 0.10Eu³⁺, and the effect of partial substituting Y³⁺/W⁶⁺/F⁻ ions on the structure and properties of this phosphor were investigated on detailed. The crystal structure of these phosphors was characterized by X-ray diffraction, scanning electron microcopy, energy-dispersive spectra, and Raman spectra. The luminescence properties and decay properties of those samples were also studied. The luminescent intensity and internal quantum efficiency of NaMg₃In(MoO₄)₅: 0.10Eu³⁺ phosphor partially substituted by Y³⁺/W⁶⁺/F⁻ ions was 1.59 and 2.76 times than that of the sample without partial substitution, due to the distort of local crystal field surrounding the Eu³⁺ ions. By employed the as-synthesized NaMg₃In_0.85Y_0.05 (Mo_0.96W_0.04O_3.84F_0.16)₅: 0.10Eu³⁺ phosphor as red component, a high-performance white LED with a low 4543 K correlated color temperature and high color-rendering index Ra = 90.0 has been fabricated with a 395 nm near-UV chip, commercial green and blue phosphors. These results implied that NaMg₃In(MoO₄)₅: 0.10Eu³⁺ phosphor partially substituted by Y³⁺/W⁶⁺/F⁻ ions could be used as a potential red-emitting candidate for white light-emitting-diodes.