Analysis of point defects in graphene using low dose scanning transmission electron microscopy imaging and maximum likelihood reconstruction

TL;DR

This paper presents a method to image and reconstruct initial point defects in graphene caused by electron irradiation using low dose scanning transmission electron microscopy and maximum likelihood algorithms, revealing intrinsic defect populations.

Contribution

It introduces a novel approach combining low dose imaging with maximum likelihood reconstruction to study defect formation in graphene.

Findings

Successful imaging of initial defects at low electron doses

Reconstruction of defect structures using maximum likelihood algorithms

Insights into defect dynamics under electron irradiation

Abstract

Freestanding graphene displays an outstanding resilience to electron irradiation at low electron energies. Point defects in graphene are, however, subject to beam driven dynamics. This means that high resolution micrographs of point defects, which usually require a high electron irradiation dose might not represent the intrinsic defect population. Here, we capture the inital defects formed by ejecting carbon atoms under electron irradiation, by imaging with very low doses and subsequent reconstruction of the frequently occuring defects via a maximum likelihood algorithm.