First-principles calculations for point defects in solids
First-principles calculations for point defects in solids
复制标题
DOI：
10.1103/revmodphys.86.253
复制
发表时间：
2014-03-28
影响因子：
44.1
通讯作者：
Van de Walle, Chris G.
中科院分区：
文献类型：
--
作者：
Freysoldt, Christoph;Grabowski, Blazej;Van de Walle, Chris G.
点缺陷和杂质严重影响材料的物理性能，对材料的应用性能有决定性的影响。第一性原理计算已经作为一种强大的方法出现，它补充了实验，可以作为识别和表征缺陷的预测工具。综述了基于密度泛函理论（DFT）的晶体材料点缺陷的电子结构计算理论建模方法。建立了一个一般的热力学形式来研究与材料类别（半导体、绝缘体和金属）无关的点缺陷的物理性质，表明如何从电子结构计算中获得相关的热力学量，如地层能、熵和多余体积。讨论了超级单体法和有效外推到孤立缺陷或稀释极限的策略等实用问题。强调了交换相关泛函（DFT + U，混合泛函）的可处理近似和DFT以外的方法的最新进展。这些进步在很大程度上消除了半导体和绝缘体中由于标准DFT无法重现带隙而长期存在的缺陷形成能量的不确定性。两个案例研究说明了这种计算如何为实际材料中的点缺陷的物理和作用提供新的见解。
Point defects and impurities strongly affect the physical properties of materials and have a decisive impact on their performance in applications. First-principles calculations have emerged as a powerful approach that complements experiments and can serve as a predictive tool in the identification and characterization of defects. The theoretical modeling of point defects in crystalline materials by means of electronic-structure calculations, with an emphasis on approaches based on density functional theory (DFT), is reviewed. A general thermodynamic formalism is laid down to investigate the physical properties of point defects independent of the materials class (semiconductors, insulators, and metals), indicating how the relevant thermodynamic quantities, such as formation energy, entropy, and excess volume, can be obtained from electronic structure calculations. Practical aspects such as the supercell approach and efficient strategies to extrapolate to the isolated-defect or dilute limit are discussed. Recent advances in tractable approximations to the exchange-correlation functional (DFT + U, hybrid functionals) and approaches beyond DFT are highlighted. These advances have largely removed the long-standing uncertainty of defect formation energies in semiconductors and insulators due to the failure of standard DFT to reproduce band gaps. Two case studies illustrate how such calculations provide new insight into the physics and role of point defects in real materials.