A facile and effective strategy to synthesize orthorhombic Sr₂Al₆O₁₁:Eu²⁺,Dy³⁺ with blue-green persistent luminescence

Sr₂Al₆O₁₁:Eu²⁺,Dy³⁺ is known as a high efficient material for generating persistent luminescence. Due to its low structural stability, it is a challenge to prepare such orthorhombic material in large scale. In this work, a facile and effective strategy was designed for the preparation of Sr₂Al₆O₁₁:Eu²⁺,Dy³⁺ with high purity by combining the advantages of solid state reaction and chemical vapor deposition method. The prepared Sr₂Al₆O₁₁:Eu²⁺,Dy³⁺ could effectively store the UV light energy and emit blue-green luminescence for 240 min by slow liberation of photo-excited electrons. Its blue-green afterglow was composed of two luminescent emissions which released from the Eu centers located in different crystal fields.