Chiral Assemblies of Pinwheel Superlattices on Substrates
Abstract
The unique topology and physics of chiral superlattices make their self-assembly from nanoparticles a holy grail for (meta)materials. Here we show that tetrahedral gold nanoparticles can spontaneously transform from a perovskite-like low-density phase with corner-to-corner connections into pinwheel assemblies with corner-to-edge connections and denser packing. While the corner-sharing assemblies are achiral, pinwheel superlattices become strongly mirror-asymmetric on solid substrates as demonstrated by chirality measures. Liquid-phase transmission electron microscopy and computational models show that van der Waals and electrostatic interactions between nanoparticles control thermodynamic equilibrium. Variable corner-to-edge connections among tetrahedra enable fine-tuning of chirality. The domains of the bilayer superlattices display strong chiroptical activity identified by photon-induced near-field electron microscopy and finite-difference time-domain simulations. The simplicity and versatility of the substrate-supported chiral superlattices facilitate manufacturing of metastructured coatings with unusual optical, mechanical and electronic characteristics.
Keywords
Cite
@article{arxiv.2206.13706,
title = {Chiral Assemblies of Pinwheel Superlattices on Substrates},
author = {Shan Zhou and Jiahui Li and Jun Lu and Haihua Liu and Ji-Young Kim and Ahyoung Kim and Lehan Yao and Chang Liu and Chang Qian and Zachary D. Hood and Wenxiang Chen and Thomas E. Gage and Ilke Arslan and Alex Travesset and Kai Sun and Nicholas A. Kotov and Qian Chen},
journal= {arXiv preprint arXiv:2206.13706},
year = {2022}
}