Luminescence properties of Lu₃M₅O₁₂ : Eu³⁺ (M = Al, Ga) and effects of Bi³⁺ co-dopant

Abstract: The Eu³⁺-doped and Eu³⁺, Bi³⁺ co-doped Lu₃M₅O₁₂ (LuMG where M = Al, Ga) phosphors are synthesized by spray pyrolysis, and the crystal structure, micromorphology, luminescence properties and effects of Bi³⁺ co-dopant are investigated. X-ray diffraction reveals that the crystal structures of the matrices do not change after partial replacement of Lu³⁺ by Eu³⁺ and Bi³⁺. The phosphors exhibit the same spherical micromorphology without agglomeration and particle size distribution with a typical diameter of about 0.7 μm. The emission and excitation spectra show transitions associated with the Eu³⁺ 4f configurations. ⁷F₁ energy level splitting of Eu³⁺ in Lu₃Al₅O₁₂:Eu and stronger luminescence of Lu₃Ga₅O₁₂:Eu are observed, and the quenching concentrations of Eu³⁺ in Lu₃Al₅O₁₂:Eu and Lu₃Ga₅O₁₂:Eu are 6 and 10 mol% with respect to Lu³⁺, respectively. Introduction of Bi³⁺ enhances the emission of Eu³⁺ accompanied by the transition emission of Bi³⁺. Graphical Abstract: [Figure not available: see fulltext.]