Numerical correction of anti-symmetric aberrations in single HRTEM images of weakly scattering 2D-objects

TL;DR

This paper introduces a numerical post-processing technique to correct anti-symmetric aberrations in HRTEM images of weakly scattering 2D materials, enhancing image clarity and interpretability.

Contribution

The authors develop and validate a novel Fourier-based correction method for residual anti-symmetric aberrations in HRTEM images of 2D materials.

Findings

Effective correction of residual aberrations in simulated images.

Improved image interpretability in experimental HRTEM images.

Method allows estimation of residual aberrations through trial and error.

Abstract

Here, we present a numerical post-processing method for removing the effect of anti-symmetric residual aberrations in high-resolution transmission electron microscopy (HRTEM) images of weakly scattering 2D-objects. The method is based on applying the same aberrations with the opposite phase to the Fourier transform of the recorded image intensity and subsequently inverting the Fourier transform. We present the theoretical justification of the method and its verification based on simulated images in the case of low-order anti-symmetric aberrations. Ultimately the method is applied to experimental hardware aberration-corrected HRTEM images of single-layer graphene and MoSe2 resulting in images with strongly reduced residual low-order aberrations, and consequently improved interpretability. Alternatively, this method can be used to estimate by trial and error the residual anti-symmetric aberrations in HRTEM images of weakly scattering objects.