Understanding defect healing is necessary to control the electronic and optoelectronic performance of devices based on nanoparticle (NP) superlattices. However, a key challenge remains to understand how NP interactions and the resulting dynamics are coupled to defect self-elimination during assembly processes. Additional degrees of freedom that account for the anisotropic nature of NPs associated with rotational dynamics and torques further complicate the challenge. Here, we investigate nanocube (NC) superlattices by employing liquid-phase transmission electron microscopy, continuum theory, and molecular dynamics simulations. Our detailed analyses reveal that interparticle forces and torques due to ligand interactions dominate those from Brownian motions and van der Waals interactions. More importantly, NC translations and rotations induced by unbalanced forces and torques are transmitted to neighboring NCs, prompting “chain interactions” in a two-dimensional (2D) network and expediting self-elimination. The mechanistic understanding will further enable the design and fabrication of defect-free superlattices as well as those with tailored defects via assembly of anisotropic particles.

中文翻译：

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纳米立方体超晶格中的缺陷自消除，通过布朗、范德华和基于配体的力和扭矩的相互作用


了解缺陷修复对于控制基于纳米粒子 （NP） 超晶格的器件的电子和光电性能是必要的。然而，在装配过程中，了解 NP 相互作用和由此产生的动力学如何与缺陷自消除耦合，仍然存在一个关键挑战。与旋转动力学和扭矩相关的 NP 各向异性性质的额外自由度使挑战进一步复杂化。在这里，我们通过采用液相传输电子显微镜、连续介质理论和分子动力学模拟来研究纳米立方体 （NC） 超晶格。我们的详细分析表明，由于配体相互作用引起的粒子间力和扭矩在布朗运动和范德华相互作用中占主导地位。更重要的是，由不平衡的力和扭矩引起的 NC 平移和旋转会传递到相邻的 NC，从而在二维 （2D） 网络中引发“链式相互作用”并加速自消除。机理理解将进一步使无缺陷超晶格的设计和制造以及通过各向异性粒子的组装来定制缺陷的超晶格。