Understanding the Formation of Conductive Mesocrystalline Superlattices with Cubic PbS Nanocrystals at the Liquid/Air Interface
Understanding the Formation of Conductive Mesocrystalline Superlattices with Cubic PbS Nanocrystals at the Liquid/Air Interface
复制标题
DOI：
10.1021/acs.jpcc.8b11518
复制
发表时间：
2019-01-17
影响因子：
3.7
通讯作者：
Scheele, Marcus
中科院分区：
文献类型：
--
作者：
Maiti, Santanu;Maiti, Sonam;Scheele, Marcus
我们报道了立方 PbS 纳米晶体（NC）通过在液体/空气界面处与有机半导体定向交联形成导电介晶超结构，并通过原位掠入射小角 X 射线散射和掠入射 X 射线衍射同时监测。我们根据时间分辨散射图案确定超晶格类型、其对称性和参数以及 NC 的原子取向。超晶格收缩在配体交换过程中呈指数衰减，始终保持二维方形几何形状。我们将这种收缩归因于较小的钴/铜 4,4',4'',4"'-四氨基酞菁分子不断取代油酸。在这些超晶格中，在整个组装过程中，NC 的 [100](AL) 轴垂直于液体表面。动力学和结构结果提供了自组装过程中超结构与其在液体表面上的原子取向（随后进行配体交换）之间的直接相关性。
We report the formation of conductive mesocrystalline superstructures of cubic PbS nanocrystals (NCs) through directional cross-linking with organic semiconductors at the liquid/air interface monitored simultaneously by in situ grazing incidence small angle X-ray scattering and grazing incidence X-ray diffraction. We determine the superlattice type, its symmetry and parameters, and the atomic orientation of NCs from the time-resolved scattering patterns. The superlattice contraction follows an exponential decay during ligand exchange, preserving always the two-dimensional square geometry. We attribute the contraction to the continuous replacement of oleic acid with smaller cobalt/copper 4,4',4 '',4"'-tetraaminophthalocyanine molecules. In these superlattices, the NCs are directed with a [100](AL) axis perpendicular to the liquid surface for the whole assembly period. The kinetics and structural results provide a direct correlation between the superstructure and their atomic orientation on the liquid surface during self-assembly followed by ligand exchange.