Abstract In this study, a 640 nm center was observed in electron-irradiated type IIa diamond by low-temperature photoluminescence spectroscopy. The origin of the center was explored by temperature dependence analysis. The optical center was at 639.6 nm and adjacent to the negative nitrogen-vacancy center. According to the calculation of energy difference, the splitting of excited states of the nitrogen-vacancy center was excluded as the origin of the 640 nm center. The lattice contraction and electron-phonon coupling model was employed to fit the temperature dependence of the 640 nm center, with all results indicating that the optical center was interstitial defect-related.

中文翻译：

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电子辐照 IIa 金刚石中 640nm 中心的光致发光研究

摘要 本研究通过低温光致发光光谱在电子辐照IIa 型金刚石中观察到一个640 nm 的中心。通过温度依赖性分析探索了中心的起源。光学中心位于 639.6 nm 并与负氮空位中心相邻。根据能量差的计算，排除了氮空位中心激发态的分裂作为640 nm中心的起源。采用晶格收缩和电子-声子耦合模型来拟合 640 nm 中心的温度依赖性，所有结果表明光学中心与间隙缺陷相关。