First-principles calculations were carried out for the electronic structures of Ce³⁺ in calcium aluminate phosphors, CaAl₂O₄, and their effects on luminescence properties. Hybrid density functional approaches were used to overcome the well-known underestimation of band gaps of conventional density functional approaches and to calculate the energy levels of Ce³⁺ ions more accurately. The obtained 4f–5d excitation and emission energies show good consistency with measured values. A detailed energy diagram of all three sites is obtained, which explains qualitatively all of the luminescent phenomena. With the results of energy levels calculated by combining the hybrid functional of Heyd, Scuseria, and Ernzerhof (HSE06) and the constraint occupancy approach, we are able to construct a configurational coordinate diagram to analyze the processes of capture of a hole or an electron and luminescence. This approach can be applied for systematic high-throughput calculations in predicting Ce³⁺ activated luminescent materials with a moderate computing requirement.

中文翻译：

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CaAl ₂ O ₄：Ce ³⁺的局部结构和能级的混合密度泛函研究

对铝酸钙磷光体中的Ce ³⁺的电子结构CaAl ₂ O ₄以及它们对发光性能的影响进行了第一性原理计算。混合密度泛函方法用于克服传统密度泛函方法对带隙的众所周知的低估，并计算Ce ³⁺的能级离子更准确。获得的4f-5d激发和发射能量与测量值显示出良好的一致性。获得了所有三个位置的详细能量图，从质上解释了所有的发光现象。通过将Heyd，Scuseria和Ernzerhof的混合函数（HSE06）与约束占据方法相结合而计算出的能级结果，我们能够构造一个结构坐标图来分析空穴或电子的俘获过程，以及发光。该方法可用于系统的高通量计算，以适度的计算需求来预测Ce ³⁺活化的发光材料。