Enhancing the blue luminescence behaviour of the Na+ co-doped novel LiLaSiO4: ξTm3+ phosphor

Abstract

A number of LiLaSiO4: ξTm3+, φNa+ phosphors were prepared by a high-temperature solid-phase reaction. The phase structure and luminescence properties of the phosphors were studied by XRD and fluorescence spectra. When the monitoring wavelength is 360 nm, the LiLaSiO4: ξTm3+ phosphor can produce a 1D2→3F4 transition and emit high brightness blue light. As the molar mass fraction of the doped Tm3+ increases, the luminous intensity first increases and then decreases. When the molar mass fraction of doped Tm3+ ions, ξ, is 1.5%, the electric dipole-electric dipole interaction leads to concentration quenching. After replacing some of the Li+ ions with Na+ ions, the luminous intensity and quantum yield are significantly improved; the luminescence properties are optimal when the molar mass fraction of doped Na+ ions, φ, is 12%. The luminous colors of all the samples are located in the blue region. The color coordinates of the LiLaSiO4:1.5%Tm3+,12%Na+ phosphor is (0.138, 0.047), which is very close to standard blue light (0.148, 0.053). The single matrix white light LiLaSiO4: ξTm3+, φNa+ phosphors show excellent performance and have potential application value in the field of UV-NUV white light LEDs.