Warm-white persistent luminescence of Lu₃Al₂Ga₃O₁₂:Pr³⁺ phosphor

冯琳，王振斌，曹程，张腾，张加驰，慈志鹏，赵争妍，王育华

Key Laboratory for Magnetism Magnetic Materials of the Ministry of Education,Lanzhou University

摘 要：A warm-white emitting persistent luminescence phosphor Lu₃Al₂Ga₃O₁₂:Pr³⁺ was synthesized by solid state method at 1600 °C in air. The refined crystal structure of Lu₃Al₂Ga₃O₁₂ host was solved by X-ray diffraction（XRD）. The photoluminescence spectra, decay curve and thermoluminescence were investigated. It was revealed that the persistent luminescence originated from the f-f transitions of Pr³⁺ emitters at Lu³⁺ sites in LuO₈ polyhedrons, and it showed white color due to the ³P₀→³H₄, ³P₁→³H₅, ³P₀→³H₅, ³P₀→³H₆, ³P₀→³F₂, ³P₀→³F₃ and ³P₀→³F₄ transitions of Pr³⁺ emitters in a wide range. The persistent luminescence of Pr³⁺ in this host could be promoted by f-d transition（278 nm） but f-f transitions, due to the different thermal activation energy. The persistent luminescence of the optimal sample could be actually recorded for 3 h by the definition of 0.32 mcd/m² and was visible for more than 7 h by dark-adapted vision in darkness. The initial depth of the dominant shallow traps was calculated to be about 0.56 eV, which is suitable for persistent luminescence. The different roles of the shallow and deep traps on the persistent decay process were investigated. Accordingly, the persistent luminescence processes and mechanism of the as-synthesized Lu₃Al₂Ga₃O₁₂:Pr³⁺ phosphors were proposed.

关键词：