Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, Illinois 60607-7061, United States.
ACS Nano. 2013 Apr 23;7(4):3190-7. doi: 10.1021/nn305697q. Epub 2013 Mar 11.
We report here a method for synthesizing CdSe quantum dots (QDs) containing copper such that each QD is doped with four copper ions. The synthesis is a derivative of the cluster-seed method, whereby organometallic clusters act as nucleation centers for quantum dots. The method is tolerant of the chemical identity of the seed; as such, we have doped four copper ions into CdSe QDs using [Na(H2O)3]2[Cu4(SPh)6] as a cluster seed. The controlled doping allows us to monitor the photophysical properties of guest ions with X-ray spectroscopy, specifically XANES and EXAFS at the copper K-edge. These data reveal that copper can capture both electrons and holes from photoexcited CdSe QDs. When the dopant is oxidized, photoluminescence is quenched and the copper ions translocate within the CdSe matrix, which slows the return to an emissive state.
我们在这里报告了一种合成含有铜的 CdSe 量子点 (QD) 的方法，使得每个 QD 掺杂四个铜离子。该合成是团簇-种子方法的衍生物，其中有机金属团簇作为量子点的成核中心。该方法对种子的化学性质具有耐受性；因此，我们使用 [Na(H2O)3]2[Cu4(SPh)6] 作为团簇种子将四个铜离子掺杂到 CdSe QD 中。受控掺杂使我们能够通过 X 射线光谱（特别是铜 K 边的 XANES 和 EXAFS）监测客体离子的光物理性质。这些数据表明，铜可以从光激发的 CdSe QD 中捕获电子和空穴。当掺杂剂被氧化时，光致发光被猝灭，铜离子在 CdSe 基质中迁移，这会减缓恢复到发射状态的速度。
