Effect of Na⁺ and Sr²⁺ Substitution on the Formation of the Oxygen Vacancies in Y₃Al₂Ga₃O₁₂:Ce³⁺ Phosphor

Abstract

The low-valence cations Na⁺ and Sr²+ were selected as the co-dopants to increase the vacancies concentration in the Y_2.982Ce_0.018Al₂Ga₃O₁₂ phosphor. The successful incorporation of Na⁺ and Sr²⁺ was confirmed by the X-Ray Diffraction (XRD) results. All the samples show 5d-4f green persistent luminescence of Ce³⁺ after 450 nm excitation. The decay curves demonstrate that the persistent luminescence is effectively enhanced with Na⁺ and Sr²⁺ doping. The thermoluminescence glow curves also show not only does the trap concentration increase, but also the distribution of trap depths is broadened. In addition, the air- and H₂/Ar-annealing treatments were conducted on every as-made sample. The experimental results prove that the increased traps after the Na⁺/Sr²⁺ doping are mainly attributed to the oxygen vacancies, and the traps have a continuous and broad distribution of trap depths. We hope this work could give new inspiration for designing a high-performance persistent phosphor.

Keywords

persistent luminescence / YAGG / Na⁺ / Sr²⁺ / oxygen vacancy / charge compensation / solidstate reaction

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