The role of primary and secondary electrons in scanning transmission electron microscopy of hybrid perovskites: the CsPbBr$_{3}$ case

TL;DR

This paper investigates how primary and secondary electrons behave in scanning transmission electron microscopy of CsPbBr3, a perovskite material, using simulations to improve understanding of electron interactions for better imaging of advanced materials.

Contribution

It provides a theoretical framework for analyzing primary and secondary electron behavior in electron microscopy of perovskites, combining ab initio and Monte Carlo simulations.

Findings

Estimated reflection and transmission of electrons based on energy and sample thickness.

Analyzed spatial distribution and energy spectra of secondary electrons.

Established a framework for optimizing electron microscopy of perovskites.

Abstract

High-resolution imaging has revolutionized materials science by offering detailed insights into the atomic structures of materials. Electron microscopy and spectroscopy rely on analysing backscattered and transmitted electrons as well as stimulated radiation emission to form structural and chemical maps. These signals contain information about the elastic and inelastic electron-scattering processes within the sample, including collective and single electron excitations such as plasmons, inter- and intraband transitions. In this study, ab initio and Monte Carlo simulations were performed to investigate the behaviour of high-energy primary and secondary electrons in scanning transmission experiments on CsPbBr$_3$ nanosamples. CsPbBr$_3$ is a perovskite material known for its high photoluminescence quantum yield, making it promising for applications in light-emitting devices and solar cells. This study explores and estimates the reflection and transmission of primary and secondary electrons based on their kinetic energy as well as sample thickness and work function. The spatial distribution and energy spectra of the secondary electrons are also examined and calculated to understand their generation depth and energy dynamics. These findings establish a theoretical framework for studying electron-material interactions and can aid in optimizing scanning microscopy techniques for imaging and characterizing advanced materials.