AI 中文总结
该研究以单层MoS₂硫空位为对象，通过多类计算证实原子级有序空位排布可显著提升电荷传输性能，确立了缺陷排布作为二维材料设计的核心原则。
AI 中文摘要
二维半导体的缺陷工程主要聚焦于控制原子缺陷的性质与浓度，本研究表明，缺陷的空间排布对电子传输同样具有决定性作用。以单层MoS₂中的硫空位为模型体系，本研究通过密度泛函理论、密度泛函紧束缚计算以及量子输运模拟，探究空位有序排列的影响。研究证实，浓度为11.1%的周期性空位排布可将孤立缺陷态转化为窄色散的带内微带，而随机分布的空位仅能产生局域电子态。这种电子转变从根本上改变了电荷传输方式，使缺陷网络中出现类带传输，而非受限于离散局域态的传输。对94种非相邻四空位构型的完整对称约化集合的系统分析显示，有序模式处于宽低能流形内，无能量异常，虽非热力学基态。Au/MoS₂/Au结的器件级模拟表明，金属费米能级与空位衍生态实现有效对齐，促进电荷注入缺陷微带。因此，有序空位阵列的电流量级可达统计等效随机分布的5个数量级，且能接近或局部超过本征MoS₂的传输性能。这些发现确立了原子级缺陷有序排布为二维材料的强大设计原则，证明缺陷的组织方式（远超其浓度）为高缺陷半导体在同时保持功能与高电导率方面提供了一条途径。
英文摘要
Defect engineering in two-dimensional semiconductors has primarily focused on controlling the nature and concentration of atomic defects. Here, we show that the spatial arrangement of defects can be equally decisive in determining electronic transport. Using sulfur vacancies in monolayer MoS$_2$ as a model system, we investigate the impact of vacancy ordering through density functional theory, density functional tight-binding calculations, and quantum transport simulations. We demonstrate that a periodic vacancy arrangement at a concentration of 11.1% transforms isolated defect states into a narrow dispersive in-gap miniband, whereas randomly distributed vacancies generate only localized electronic states. This electronic transition fundamentally alters charge transport, enabling band-like propagation through the defect network rather than transport limited by disconnected localized states. A systematic analysis of the complete symmetry-reduced ensemble of 94 non-adjacent four-vacancy configurations shows that the ordered pattern lies within a broad low-energy manifold and is not energetically anomalous, although it is not the thermodynamic ground state. Device-level simulations of Au/MoS$_2$/Au junctions reveal efficient alignment of the metal Fermi level with vacancy-derived states, promoting charge injection into the defect miniband. As a result, ordered vacancy arrays exhibit electrical currents up to five orders of magnitude higher than statistically equivalent random distributions and can approach, or locally exceed, the transport performance of pristine MoS$_2$. These findings establish atomic-scale defect ordering as a powerful design principle for two-dimensional materials, demonstrating that the organization of defects, beyond their concentration alone, provides a route to simultaneously preserve functionality and high electrical conductivity in highly defective semiconductors.
Comments24 pages, 6 figures, submitted for peer-review
