Aggregation/assembly induced emission (AIE) has been observed for metal nanoclusters (NCs), but the origin of the enhanced emission is not fully understood, yet. In this work, the significant contribution of metal defects on AIE is revealed by engineering the self-assembly process of Cu NCs using ethanol. The presence of ethanol leads to a rapid assembly of NCs into ultrathin nanosheets, promoting the formation of metal defects-rich surface. Detailed studies and computer simulation confirm that the metal defects-rich nanosheets possess increased Cu(I)-to-Cu(0) ratio, which greatly influences ligand-to-metal-metal charge transfer and therewith facilitates the radiative relaxation of excitons. Consequently, the Cu NCs self-assembly nanosheets exhibit obvious emission enhancement.

中文翻译：

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金属缺陷在组装诱导Cu纳米团簇发射中的贡献

已经观察到金属纳米簇 (NC) 的聚集/组装诱导发射 (AIE)，但尚未完全了解增强发射的起源。在这项工作中，通过使用乙醇设计 Cu NCs 的自组装过程，揭示了金属缺陷对 AIE 的重要贡献。乙醇的存在导致 NCs 快速组装成超薄纳米片，促进富含金属缺陷的表面的形成。详细研究和计算机模拟证实，富含金属缺陷的纳米片具有增加的 Cu(I) 与 Cu(0) 的比率，这极大地影响了配体-金属-金属的电荷转移，从而促进了激子的辐射弛豫。因此，Cu NCs 自组装纳米片表现出明显的发射增强。