Abstract The density functional theory with the Hubbard U parameter method was used to evaluate the lattice structure, electronic structures, and optical spectra of MgAl2O4 crystals with cation vacancies. We analyzed the electronic structures of oxygen atoms around the cation vacancies. The holes prefers to distribute themselves on all the nearest oxygen atoms around the vacancy rather than to localize on a single oxygen atom. We propose the color center models V Mg 2 − − [ O 2 3 − ] 2 + and V Al 3 − − [ O 2 3 − ] 3 + for the magnesium vacancy and the aluminum vacancy with localized hole states. Taking into account electron-phonon coupling, we obtained the optical spectra of the cation vacancies with localized hole states. The calculated absorption peaks of the cation vacancies with localized hole states are consistent with the experimental results. The emission peaks of the magnesium vacancy and the aluminum vacancy with localized hole states are at 2.63 eV and 2.62 eV, close to that of the F center at 2.69 eV. We predict that cation vacancies with localized hole states will act as a source of blue luminescence.

中文翻译：

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MgAl2O4 晶体中具有局域空穴态的阳离子空位研究

摘要 利用密度泛函理论和Hubbard U 参数法，评估了具有阳离子空位的MgAl2O4 晶体的晶格结构、电子结构和光谱。我们分析了阳离子空位周围氧原子的电子结构。空穴更喜欢将自己分布在空位周围所有最近的氧原子上，而不是定位在单个氧原子上。我们提出了镁空位和具有局部空穴态的铝空位的色心模型V Mg 2 - - [ O 2 3 - ] 2 + 和V Al 3 - - [ O 2 3 - ] 3 + 。考虑到电子-声子耦合，我们获得了具有局部空穴态的阳离子空位的光谱。具有局部空穴态的阳离子空位的计算吸收峰与实验结果一致。具有局部空穴态的镁空位和铝空位的发射峰分别为 2.63 eV 和 2.62 eV，接近 F 中心的 2.69 eV。我们预测具有局部空穴态的阳离子空位将作为蓝色发光的来源。