Luminescence properties and energy transfer of La3Ga5SiO14:Eu3+, Tb3+ phosphors

Abstract

In this paper, a series of Eu³⁺/Tb³⁺ doped La₃Ga₅SiO₁₄ (LGS:Eu³⁺, Tb³⁺) phosphors with excellent performance have been synthesized by high-temperature solid-phase method. The effects of Eu³⁺ and Tb³⁺ doping in LGS on the host lattice were analyzed by X-ray diffraction (XRD). X-ray photoelectron spectroscopy (XPS) proved that the Eu³⁺ and Tb³⁺ ions were successfully doped into the LGS host. The doped Eu³⁺/Tb³⁺ ions only occupy the eight-coordinated La³⁺ sites. The concentration quenching points of LGS:Eu³⁺ and LGS:Tb³⁺ phosphors were determined to be 0.16 and 0.18, respectively. The luminescence performance and fluorescence lifetime of LGS:Eu³⁺, Tb³⁺ were studied. LGS:Eu³⁺, Tb³⁺ phosphors successfully realized Tb³⁺ → Eu³⁺ energy transfer to enhance Eu³⁺ luminescence. The energy transfer mechanism is speculated on using the experimental results. The energy transfer efficiency from Tb³⁺ to Eu³⁺ is about 66.83% in La_2.46Tb_0.18Eu_0.36Ga₅SiO₁₄. The LGS:Eu³⁺, Tb³⁺ phosphors can achieve tunable luminescence by controlling the doping concentrations of Eu³⁺ and Tb³⁺. The ΔE is calculated to be 0.2567 eV for the La_2.70Eu_0.12Tb_0.18Ga₅SiO₁₄ phosphor.