Preparation And Photoluminescence Properties Of Oxyfluoride-based Phosphors

Nowadays, phosphor conversion methods has been the main way to realize white light emission. Oxyfluoride have been widely studied as the matrix material of phosphors because of its good physical and chemical stability and low synthesis temperature. In this paper, the oxyfluoride-based phosphors for solid-state lighting were synthesized by the methods of crystal field electronegativity regulation and energy transfer, which based on the structure design of oxyfluride matrix materials. The main research contents were divided into the followings:?1? Oxyfluoride-based Na₅Y₄?SiO₄?₄F:Eu³⁺ phosphors were designed and synthesized. The crystal structure of the phosphor were analyzed by X-ray diffraction and its luminescent properties were detected by the fluorescence spectrometer. The effect of electronegative enhancement on the luminescence properties of phosphors were studied by compared with the luminescence properties of oxide-based NaYSiO4:Eu³⁺ phosphor. The results show that the Na5Y4?SiO4?4F:Eu³⁺was a kind of high performance ultraviolet excited red phosphor.?2? Oxyfluoride-based Na₂CaPO₄F:Ce³⁺, Mn²⁺ phosphors which excited by 254 nm were designed and synthesized. The crystal structures were analyzed by X-ray diffraction and the luminescent properties were detected by the fluorescence spectrometer. The effect of electronegativity enhance on the 5d electron transition of Ce³⁺ ions were studied by the method of introduction of F- ions throw the comparison of the luminescent properties of Oxyfluoride-based Na2CaPO4F:Ce³⁺ phosphors and oxide-based NaCaPO₄:Ce³⁺ phosphors. The Na2CaPO4F:Ce³⁺, Mn²⁺ red phosphors were synthesized by Ce³⁺/Mn²⁺ co-doping methods, and the mechanism of energy transfer between Ce³⁺ ions and Mn²⁺ ions were also studied.?3? Oxyfluoride-based Na₂Ca₄?PO₄?₃F:Ce³⁺, Mn²⁺ single-phase white-light emitting phosphors which excited by 254 nm were designed and synthesized. The crystal structures were analyzed by X-ray diffraction and the luminescence properties were detected by fluorescence spectrometer. The mechanism of energy transfer between Ce³⁺ ions and Mn²⁺ ions in Na2Ca4?PO4?3F:Ce³⁺, Mn²⁺ were studied. The thermal stability of Na2Ca4?PO4?3F:Ce³⁺, Mn²⁺ single-phase white-light emitting phosphors were also studied.