Quantifying Angular Correlations between the Atomic Lattice and Superlattice of Nanocrystals Assembled with Directional Linking

TL;DR

This paper presents a combined X-ray scattering and cross correlation method for detailed structural analysis of mesocrystalline nanoparticle assemblies, enabling comprehensive characterization of lattice and superlattice correlations in a single experiment.

Contribution

It introduces a novel approach that combines X-ray techniques to analyze the full structure and orientation of nanocrystal assemblies with statistical robustness.

Findings

Effective structural characterization of mesocrystals achieved

Correlation between atomic and superlattice orientations established

Method enables linking structure with optoelectronic properties

Abstract

We show that the combination of X-ray scattering with a nanofocused beam and X-ray cross correlation analysis is an efficient means for the full structural characterization of mesocrystalline nanoparticle assemblies with a single experiment. We analyze several hundred diffraction patterns of individual sample locations, i.e. individual grains, to obtain a meaningful statistical distribution of the superlattice and atomic lattice ordering. Simultaneous small- and wide-angle X-ray scattering of the same sample location allows us to determine the structure and orientation of the superlattice as well as the angular correlation of the first two Bragg peaks of the atomic lattices, their orientation with respect to the superlattice, and the average orientational misfit due to local structural disorder. This experiment is particularly advantageous for synthetic mesocrystals made by the simultaneous self-assembly of colloidal nanocrystals and surface-functionalization with conductive ligands. While the structural characterization of such materials has been challenging so far, the present method now allows correlating mesocrystalline structure with optoelectronic properties.