铕掺杂氧化钇的密度泛函第一性原理研究

Study of Eu-doped yittria by density functional theory calculations

摘要:

基于第一性原理密度泛函，开展了氧化钇（Y2O3）的晶体结构和电子性质的计算研究，对比实验结果验证了计算方法的可行性。通过超元胞模型的密度泛函计算，探究了氧化钇主要本征点缺陷和不同格点阳离子铕（Eu）取代掺杂的形成能。结果表明，富氧条件有利于Eu杂质原子掺入氧化钇晶格，低费米能条件下，Eu原子易于取代周围6个O原子具有中心反演对称性的钇原子；在高费米能条件下，杂质原子对两种格点钇原子取代几率相等。本研究对于提升Eu掺杂氧化钇的发光效率具有一定的指导意义。

Abstract:

The structural and electronic properties of yittria are studied by density functional theory calculations. The results agree well with the experimental ones. Based on the supercell method, the intrinsic and Eu-doped defects are investigated. Analyzing the formation energies of various defects, we find that the Eu atom substitutes for the cations more easily under the O-rich condition. The b-site as an inversion center is preferred with the lower Fermi energy, while the probability of the d-site with lower symmetry is equal to that of b-site. The results are instructive to improve the luminous efficiency.