We have measured room temperature and low temperature luminescence spectra of Eu³⁺ in SrAl₂O₄:Eu^3+/2+. The powder samples were synthesized in reducing atmosphere above 1200 °C, cooled down to room temperature in the same atmosphere, and heated again to 750 °C in air. The analysis of the emission spectra of Eu³⁺ showed the presence of multiple sites for this ion, revealing that many different charge compensating defects are located in close vicinity to the europium ions. These defects can be positioned in each of the two void sites identified in the crystal structure of SrAl₂O₄. Lifetime measurements reveal the presence of very short-lived excited Eu³⁺ species with lifetimes around 0.7 μs, in addition to species with lifetimes around 1.6 ms. These very short lifetimes are postulated to be related to intervalence charge transfer with few remaining divalent Eu²⁺ ions which had not been oxidized by the thermal treatment in air. This type of intervalence charge transfer between divalent to the trivalent rare earth ion could be crucially associated to processes involved in the afterglow of the persistent phosphor SrAl₂O₄:Eu²⁺,Dy³⁺.

我们测量了 SrAl ₂ O ₄ :Eu ^3+/2+中 Eu ^{3+ 的}室温和低温发光光谱。粉末样品在1200°C以上的还原气氛中合成，在相同气氛中冷却至室温，并在空气中再次加热至750°C。Eu ³⁺的发射光谱分析表明该离子存在多个位点，表明许多不同的电荷补偿缺陷位于铕离子附近。这些缺陷可以位于 SrAl ₂ O ₄的晶体结构中确定的两个空位中的每一个中。寿命测量揭示了非常短暂的兴奋Eu的存在除了寿命约为 1.6 ms 的物种之外，还有³⁺种寿命约为 0.7 μs 的物种。这些非常短的寿命被假定与间隔电荷转移有关，其中几乎没有剩余的二价 Eu ²⁺离子未被空气中的热处理氧化。这种二价与三价稀土离子之间的间隔电荷转移可能与持久性磷光体 SrAl ₂ O ₄ :Eu ²⁺ ,Dy ³⁺的余辉过程有关。