发表机构
University of California, Santa Barbara; US Naval Research Laboratory; Lawrence Livermore National Laboratory; Center for Physical Sciences and Technology (FTMC)（加州大学圣塔芭芭拉分校; 美国海军研究实验室; 劳伦斯利弗莫尔国家实验室; 物理科学和技术中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究从第一性原理建立理论框架，计算多种材料的极化子自捕获速率，揭示其对p型导电性的潜在影响，所得寿命与实验结果吻合。
AI 中文摘要
极化子形成也称为自捕获，是一种类似于点缺陷或杂质处非辐射载流子捕获的过程。本研究建立了从第一性原理确定小空穴或电子极化子形成所需时间的理论框架，采用基于Koopmans兼容杂化泛函的精确全第一性原理方法。自捕获速率由两个分量的乘积构成：通过一维近似计算的非辐射捕获系数，以及基于超胞中有限尺寸相互作用阐明其物理机制的极化子位点最大密度。将该方法应用于多种已知存在空穴极化子的技术相关材料（Ga₂O₃、Al₂O₃、BeO、KBr、MgO、NaCl、SiO₂、SnO₂、TiO₂和ZnO），以及金红石TiO₂中的电子极化子，还研究了新兴半导体金红石GeO₂，发现其极化子形成可能阻碍p型导电性。计算得到的自捕获寿命跨度达7个数量级，从10⁻¹到10⁶ ps，与现有实验结果一致，为固体中载流子定域和弛豫动力学提供了深入见解。
英文摘要
Polaron formation, also known as self-trapping, is a process akin to nonradiative carrier capture at point defects or impurities. In this work, we develop the formalism to determine how long it takes to form a small hole or electron polaron from first principles. We employ an accurate, fully first-principles approach based on a Koopmans compliant hybrid functional. The self-trapping rate is the product of two components: the nonradiative capture coefficient, which we evaluate using a one-dimensional approximation, and the maximum density of polaron sites, whose physics we elucidate based on finite-size interactions present in supercells. We apply our methodology to several technologically relevant materials known to host hole polarons, Ga$_2$O$_3$, Al$_2$O$_3$, BeO, KBr, MgO, NaCl, SiO$_2$, SnO$_2$, TiO$_2$, and ZnO, and to an electron polaron in rutile TiO$_2$. We also study an emerging semiconductor, rutile GeO$_2$, where we find that polaron formation could hamper $p$-type conductivity. The calculated self-trapping lifetimes span 7 orders of magnitude, from $10^{-1}$ to $10^6$~ps, in agreement with experiments where available, and providing detailed insight into the dynamics of carrier localization and relaxation in solids.
