标题： 通过化学气相沉积钻石中的氢驱动缺陷化学工程氮空位中心用于量子应用：NVHx解离为NV，468nm中心的来源以及棕色变色的原因 显示英文标题

标题： Engineering NV Centers via Hydrogen-Driven Defect Chemistry in CVD Diamonds for Quantum Applications: NVHx Dissociations into NV, Origin of 468nm Center, and Cause of Brown Coloration

摘要： 实现高NV中心转换效率仍然是推进基于金刚石的量子技术的关键挑战。 普遍接受的NV形成机制是，在退火过程中，辐射引起的空位变得可移动，并被取代氮原子捕获。 然而，所提出的机制并未考虑氢在金刚石中的存在及其对NV形成路径的影响。 尽管第一性原理计算强烈表明，在CVD金刚石生长过程中会形成氢钝化的NV中心。 最近的实验观察显示，作为生长的CVD金刚石中NV中心、棕色着色和468 nm发光中心之间存在强烈的空间相关性，这促使我们研究这些现象在NxVHy型复合缺陷存在下的原子起源。 我们使用混合密度泛函理论DFT计算和不同氮含量生长的CVD金刚石的光谱分析来研究生长过程中的缺陷平衡。 我们将468 nm中心识别为NVH-缺陷，即一个氢钝化的NV中心，并将270 360和520 nm处的特征紫外-可见吸收带归因于NxVHy复合体。 我们的研究结果表明，氢在生长过程中稳定这些缺陷起着核心作用。 我们进一步表明，在生长后的辐照和退火过程中，NVHx复合缺陷会分解为NV中心和间隙氢，补充了取代氮的空位捕获。 这些结果提供了一个统一的图像，说明了CVD金刚石中棕色着色、468 nm中心和NV形成的缺陷化学基础，通过利用氢的作用和NVHx复合体的解离，为优化金刚石合成和加工以用于量子应用提供了新的见解。 显示英文摘要

摘要： Achieving high NV center conversion efficiency remains a key challenge in advancing diamond-based quantum technologies. The generally accepted mechanism for NV formation is that irradiation-induced vacancies become mobile during annealing and are trapped by substitutional nitrogen. However, the suggested mechanism does not consider the presence and role of hydrogen in the diamond and its influence on the NV formation pathway. This is despite ab-initio calculations, which strongly suggest the formation of hydrogen-passivated NV centers during CVD diamond growth. Recent experimental observations showing a strong spatial correlation between NV centers, brown coloration, and the 468 nm luminescence center in as-grown CVD diamonds prompted us to investigate the atomistic origin of these phenomena in the presence of NxVHy-type complex defects. We used hybrid density functional theory DFT calculations and spectroscopic analysis of CVD diamonds grown with varying nitrogen content to investigate defect equilibria during growth. We identified the 468 nm center as the NVH- defect, a hydrogen-passivated NV center, and assigned the characteristic UV-VIS absorption bands at 270 360 and 520 nm to NxVHy complexes. Our findings reveal that hydrogen plays a central role in stabilizing these defects during growth. We further showed that NVHx complex defects dissociate into NV centers and interstitial hydrogen during post-growth irradiation and annealing, complementing vacancy trapping by substitutional nitrogen. These results provide a unified picture of the defect chemistry underlying brown coloration, 468 nm center, and NV formation in CVD diamonds, offering new insights for optimizing diamond synthesis and processing for quantum applications by taking advantage of hydrogens role and dissociation of NVHx complexes.