[论文解读] Substitutional oxygen as the origin of the 3.5 eV luminescence in hexagonal boron nitride

M. Maciaszek|arXiv (Cornell University)|Feb 5, 2026

Diamond and Carbon-based Materials Research被引用 0

一句话总结

该论文显示，六方氮化硼中的3.5 eV发光源于中性氧置代N形成的ON捕获空穴过程，涉及电荷态变化和显著的结构重新构型；预测的发射能量3.63 eV与实验一致。

ABSTRACT

Although point defects in hexagonal boron nitride exhibiting single-photon emission attract considerable interest, a broader understanding of defect physics and chemistry in hBN remains limited, potentially hindering further development. Oxygen is among the most common impurities in hBN, and numerous studies have reported a pronounced photoluminescence band centered near 3.5 eV following oxygen incorporation, yet its microscopic origin has remained unresolved. Here, we demonstrate that this emission originates from hole capture by neutral oxygen substituting for nitrogen (ON). The transition mechanism is non-trivial, involving not only a change in charge state but also a substantial structural reconfiguration: the positive and neutral states exhibit markedly different geometries and symmetries. In the neutral state the defect adopts a low-symmetry configuration with out-of-plane displacements of the oxygen and neighboring atoms. The calculated emission energy (3.63 eV) and lineshape are in excellent agreement with experiment.

研究动机与目标

• 理解 hBN 中3.5 eV 发光的微观起源。
• 研究 hBN 常见氧杂质在缺陷中的作用。
• 表征发射过程中 ON 缺陷伴随的电子结构与结构变化。

提出的方法

• 在六方氮化硼中建模 ON 缺陷并分析其电荷态跃迁。
• 计算空穴捕获跃迁的发射能量和谱线形。
• 评估正电荷态与中性态之间的几何与对称性变化。

实验结果

研究问题

• RQ1 氧引入后，hBN 中观察到的3.5 eV发光的微观起源是什么？
• RQ2 ON 缺陷的电荷态变化和结构重新配置如何影响发射能量与谱线形？
• RQ3 中性 ON 缺陷是否呈现低对称性的几何并伴随特定的平面外位移，从而影响发光？
• RQ4 所计算的发射能量是否与实验观测的3.5 eV带一致？

主要发现

• hBN 的3.5 eV 发光源于中性 ON 的空穴捕获。
• 一个非平凡的跃迁机制同时涉及电荷态改变和显著的结构重新构型。
• 中性态下，ON 采用低对称性构型，氧及邻近原子存在平面外位移。
• 所计算的发射能量为3.63 eV，谱线形与实验数据高度一致。