First-principles simulation of inelastic electron beam-matter interactions and their effect on knock-on damage cross sections

Electron irradiation by transmission electron microscopy is an effective method for engineering the properties and morphology of 2-dimensional (2D) materials with a high degree of spatial control. It follows that many computational models have been developed to predict the rates of atomic displacements in 2D materials under such irradiation. However, while current models give reasonable predictions for conductors, they often vastly underestimate the displacement rates in insulators. In this work, we combine density functional theory with quantum electrodynamics to demonstrate how the consideration of electron-electron scattering can lead to the prediction of significantly higher displacement rates in gapped materials, reducing the disparity between theory and experiment. This new model would be a boon for materials engineers, allowing for the controlled manipulation of any 2D material for targeted functionality.