Tm3+→Tb3+ energy transfer induced color-tunable in double-doped LiLaSiO4 phosphors

Abstract

In this paper, a series of color-tunable LiLaSiO4:βTm3+, γTb3+ phosphors were quickly synthesized by microwave-assisted solid-phase reaction method. Under proper ultraviolet light excitation, Tm3+ ions produce 1D2→3F4 energy level transition and emit blue light, and the concentration quenching point is β = 1.5%mol. The color coordinates are (0.139, 0.046), compared with commercial blue phosphors. It has a higher color purity and color saturation. The Tb3+ ions produce 5D4→7F5 energy level transition and emit green light, and the color coordinate is (0.324, 0.508). In Tm3+-Tb3+ double-doped LiLaSiO4 phosphors, the concentration quenching point of Tb3+ ions is γ = 6%mol. By characterizing the fluorescence lifetime and the luminous intensity of the Tm3+-Tb3+ co-doped LiLaSiO4 phosphor, it is verified that there is an energy transfer of Tm3+→Tb3+ in the phosphor. The energy transfer efficiency and energy transfer mechanism have been investigated in detail. From the researched luminous properties, it is found that Tm3+-Tb3+ co-doped LiLaSiO4 phosphor is an ideal material for light-emitting diodes, luminescent materials and fluorescent display devices.