Comparative Study of Covalent and van der Waals CdS Quantum Dot Assemblies from Many-Body Perturbation Theory
Comparative Study of Covalent and van der Waals CdS Quantum Dot Assemblies from Many-Body Perturbation Theory
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DOI：
10.1021/acs.jpclett.2c02856
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发表时间：
2022-10-24
影响因子：
5.7
通讯作者：
Liu, Zhen-Fei
中科院分区：
文献类型：
--
作者：
Aryal, Sandip;Frimpong, Joseph;Liu, Zhen-Fei
量子点（QD）组装体是由QD的聚集体制成的纳米结构网络，并且与离散QD相比具有改进的电荷和能量转移效率。使用第一性原理多体微扰理论，我们系统地比较了两种类型的CdS量子点组件的电子和光学性质的实验研究：（i）量子点凝胶，其中单个量子点通过二硫键或多硫键共价连接，和（ii）量子点纳米晶体，其中单个量子点通过货车德瓦尔斯相互作用结合。我们的工作说明了当离散量子点组装成1D，2D和3D凝胶和纳米晶体时，电子和光学性质如何演变，以及这些系统中的单体和多体相互作用如何影响组装体维数增加时的趋势。此外，我们的工作揭示了二硫或多硫共价键在激子局域化中的关键作用，这突出了QD凝胶和QD纳米晶体之间的差异。
Quantum dot (QD) assemblies are nanostructured networks made from aggregates of QDs and feature improved charge and energy transfer efficiencies compared to discrete QDs. Using first-principles many-body perturbation theory, we systematically compare the electronic and optical properties of two types of CdS QD assemblies that have been experimentally investigated: (i) QD gels, where individual QDs are covalently connected via di-or polysulfide bonds, and (ii) QD nanocrystals, where individual QDs are bound via van der Waals interactions. Our work illustrates how the electronic and optical properties evolve when discrete QDs are assembled into 1D, 2D, and 3D gels and nanocrystals, as well as how the one-body and many-body interactions in these systems impact the trends as the dimensionality of the assembly increases. Furthermore, our work reveals the crucial role of the di-or polysulfide covalent bonds in the localization of the excitons, which highlights the difference between QD gels and QD nanocrystals.