Li Wenke, Zhao Xiujian, Liu Chao, Coudert François-Xavier
State Key Laboratory of Silicate Materials for Architectures , Wuhan University of Technology , Hubei 430070 , China.
Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris , 75005 Paris , France.
J Am Chem Soc. 2020 Feb 26;142(8):3905-3912. doi: 10.1021/jacs.9b12073. Epub 2020 Feb 13.
We have probed the local atomic structure of the interface between a CdSe quantum dot (QD) and a sodium silicate glass matrix. Using ab initio molecular dynamics simulations, we determined the structural properties and bond lengths, in excellent agreement with previous experimental observations. On the basis of an analysis of radial distribution functions, coordination environment, and ring structures, we demonstrate that an important structural reconstruction occurs at the interface between the CdSe QD and the glass matrix. The incorporation of the CdSe QD disrupts the Na-O bonds, while stronger SiO tetrahedra are reformed. The existence of the glass matrix breaks the stable 4-membered (4MR) and 6-membered (6MR) Cd-Se rings, and we observe a disassociated Cd atom migrated in the glass matrix. Besides, the formation of Se-Na and Cd-O linkages is observed at the CdSe QD/glass interface. These results significantly extend our understanding of the interfacial structure of CdSe QD-doped glasses and provide physical and chemical insight into the possible defect structure origin of CdSe QD, of interest to the fabrication of the highly luminescent CdSe QD-doped glasses.
我们探究了CdSe量子点（QD）与硅酸钠玻璃基质之间界面的局部原子结构。通过从头算分子动力学模拟，我们确定了结构性质和键长，与先前的实验观察结果高度吻合。基于对径向分布函数、配位环境和环结构的分析，我们证明在CdSe量子点与玻璃基质之间的界面处发生了重要的结构重构。CdSe量子点的掺入破坏了Na-O键，同时形成了更强的SiO四面体。玻璃基质的存在打破了稳定的4元（4MR）和6元（6MR）Cd-Se环，并且我们观察到一个解离的Cd原子在玻璃基质中迁移。此外，在CdSe量子点/玻璃界面处观察到了Se-Na和Cd-O键的形成。这些结果显著扩展了我们对CdSe量子点掺杂玻璃界面结构的理解，并为CdSe量子点可能的缺陷结构起源提供了物理和化学见解，这对于制备高发光的CdSe量子点掺杂玻璃具有重要意义。
