基于第一性原理的单层碳化硅中的键重构与空位聚集
Bond reconstruction and vacancy clustering in monolayer silicon carbide from first principles
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中文总结 AI 辅助
研究单层碳化硅中空位相关结构的键重构机制，采用密度泛函理论，揭示单空位及聚集体的重构情况，如孤立单空位的面内面外变化、碳单空位对光学活性的影响等，还发现一种稳定聚集体有望成为红外色心候选。
中文摘要 AI 辅助
与空位相关结构中的键重构会影响其形成能、对称性以及电子和光学性质。利用密度泛函理论，研究了单层碳化硅中单空位和空位聚集体的键重构机制。多种键描述符表明孤立单空位会发生面内重构和面外畸变，共同塑造其稳定性和电子结构。对于紧密的空位聚集体，键重构是关键的稳定机制。在碳单空位中，重构抑制光学活性。而由围绕硅空位的三个碳空位组成的高度稳定聚集体有望成为红外色心候选，结合三重基态和有利的发射德拜-瓦勒因子。这些结果突出了键重构在定义二维碳化硅中空位缺陷量子性质方面的作用。
英文摘要
Bond reconstruction in vacancy-related structures affects their formation energies, symmetries, and electronic and optical properties. Using density functional theory, we investigate bond reconstruction mechanisms of monovacancies and vacancy aggregates in monolayer silicon carbide. Multiple bond descriptors reveal that isolated monovacancies undergo both in-plane reconstruction and out-of-plane distortion, which together shape their stability and electronic structure. For compact vacancy aggregates, we show that bond reconstruction acts as a key stabilization mechanism. However, in carbon monovacancy, reconstruction suppresses optical activity. In contrast, a highly stable aggregate composed of three carbon vacancies surrounding a silicon vacancy emerges as a promising infrared color-center candidate, combining a triplet ground state with a favorable Debye-Waller factor of the emission. These results highlight the role of bond reconstruction in defining the quantum properties of vacancy defects in two-dimensional silicon carbide.
