AI 中文总结
本研究采用密度泛函方法结合BSE@G₀W₀计算，探究C2型反铁磁α-MnO₂本征点缺陷的结构、电子、磁学及光学性质，明确缺陷的竞争关系与光学响应特征，为其可控掺杂及性能优化提供理论依据。
AI 中文摘要
α-MnO₂因结构灵活性和缺陷驱动的功能特性，成为电子、光电子及能源应用领域的新兴材料。在α-MnO₂合成过程中，本征氧空位易形成，通常需通过外来掺杂剂补偿。因此，深入理解本征缺陷对实现可控外来掺杂、优化材料性能至关重要。本研究采用密度泛函方法，探究基态C2型反铁磁α-MnO₂在存在本征点缺陷（包括间隙原子、空位及反位缺陷）时的结构、电子、磁学及光学性质，计算其热力学稳定性，并引入静电修正以消除虚假长程相互作用。结果显示：Mn间隙原子（Mnᵢ）和Mn反位缺陷O（Mn_O）引入浅施主能级，而氧空位（V_O）表现出两性行为，可作为补偿中心；计算得到的缺陷形成能表明，施主型与受主型本征缺陷间存在显著竞争，在富Mn和富O生长条件下均会引发强烈的本征缺陷补偿；Mn空位（V_Mn）在带隙内保持电离状态，表现为浅受主，暗示其在合适的非平衡生长条件下具有潜在作用，而O反位缺陷Mn（O_Mn）则形成深受主能级。基于BSE@G₀W₀的计算表明，化学计量比α-MnO₂具有强各向异性光学响应，本征点缺陷会引入显著的带隙激发并增强介电屏蔽，其中空位产生的效应最为显著。
英文摘要
$α$-MnO$_2$ is an emerging material for electronic, optoelectronic, and energy applications, owing to its structural flexibility and defect-driven functionality. During synthesis of $α$-MnO$_2$, native oxygen vacancies readily form and are typically compensated by foreign dopants. A thorough understanding of intrinsic defects is therefore essential for enabling controlled extrinsic doping and optimizing material performance. Using density functional approach, we investigate the structural, electronic, magnetic, and optical properties of the ground state C2-type antiferromagnetic $α$-MnO$_2$ in the presence of native point defects, including interstitials, vacancies, and antisites. We compute their thermodynamic stability, incorporating electrostatic corrections to eliminate spurious long-range interactions. Mn interstitial (Mn$_\text{i}$) and Mn antisite O (Mn$_\text{O}$) introduce shallow donor levels, whereas O-vacancy (V$_\text{O}$) exhibit amphoteric behavior and act as compensating centers. The calculated defect formation energies reveal pronounced competition between donor- and acceptor-type native defects, leading to strong intrinsic defect compensation under both Mn-rich and O-rich growth conditions. Mn vacancy (V$_\text{Mn}$) remains ionized across the band gap and behaves as a shallow acceptor, suggesting its potential role under suitable non-equilibrium growth conditions, whereas O antisite Mn (O$_\text{Mn}$) forms deep acceptor levels. BSE@G$_0$$W_0$ calculations reveal a strongly anisotropic optical response in stoichiometric $α$-MnO$_2$, while native point defects introduce pronounced sub-gap excitations and enhanced dielectric screening, with vacancies producing the largest effect.
CommentsMain text: 17 pages, 13 figures; Supplemental: 16 pages, 15 figures
Journal refPhys. Rev. B 114 (2026) 084108
