ZnO中主族二聚体缺陷的第一性原理设计：候选量子缺陷
First-principles design of main-group dimer defects in ZnO as candidate quantum defects
浏览论文内容
中文总结 AI 辅助
该研究通过杂化密度泛函理论设计ZnO中的主族施主-受主二聚体缺陷，发现(Si_Zn-B_O)^+等缺陷具备可见光跃迁、亚微秒辐射寿命等特性，有望作为光活性自旋缺陷候选。
中文摘要 AI 辅助
氧化锌（ZnO）是一种具有成熟生长技术的宽禁带半导体，是光活性量子自旋的理想宿主材料，但ZnO中的光活性量子缺陷仍大多未被探索。本文中，我们识别并表征了ZnO中的一类双取代杂质，其由主族施主-受主（DA）对形成，作为光活性量子缺陷的候选。我们采用杂化密度泛函理论（DFT），系统研究了双取代DA络合物及其缺陷物理特性，包括电子结构、热力学稳定性和光学性质。所提出的缺陷具有孤立缺陷态、受主位点上的强自旋局域化以及C₃v对称性。重要的是，DA对的电子结构主要由其组成原子的原子性质决定。我们进一步研究了它们的光学特性，包括零声子线（ZPL）、辐射寿命和非辐射复合，以评估其作为色心的可行性。值得注意的是，在这些二聚体中，(Si_Zn-B_O)^+和(Ge_Zn-B_O)^+表现出可见光范围的光学跃迁，辐射寿命在亚微秒级，且电荷态对光电离具有鲁棒性；而(Si_Zn-C_O)^(2+)的黄-里斯因子最小，约为5.6。我们的研究结果提出了ZnO中一类新型主族施主-受主缺陷，作为光活性自旋缺陷的有希望候选。
英文摘要
Zinc oxide (ZnO), a wide-band-gap semiconductor with mature growth techniques, is a promising host for optically active quantum spins. Yet, optically active quantum defects in ZnO remain largely unexplored. Here, we identify and characterize a family of double substitutional impurities in ZnO, formed by main-group donor-acceptor (DA) pairs, as candidates for optically active quantum defects. Using hybrid density functional theory (DFT), we systematically investigate double substitutional DA complexes and their defect physics, including electronic structure, thermodynamic stability, and optical properties. The proposed defects exhibit isolated defect states, strong spin localization on the acceptor site, and $C_{3v}$ symmetry. Importantly, the electronic structure of the DA pairs is largely determined by the atomic properties of their constituent atoms. We further examine their optical characteristics, including zero-phonon lines (ZPLs), radiative lifetimes, and nonradiative decay to assess their viability as color centers. Notably, among the dimers, (Si$_{Zn}$-B$_O$)$^+$ and (Ge$_{Zn}$-B$_O$)$^+$ exhibit visible optical transitions with sub-microsecond radiative lifetimes and robust charge states against optical ionization, while (Si$_{Zn}$-C$_O$)$^{2+}$ shows the smallest Huang-Rhys factor, approximately 5.6. Our results propose a new family of main-group donor-acceptor defects in ZnO as promising candidates for optically active spin defects.
