Electron-beam-induced cracking in organic-inorganic halide perovskite thin films

The curious phenomenon of cracking in organic-inorganic halide perovskite (OIHP) thin films for solar cells during scanning electron microscopy (SEM) can be seen in literally thousands of published SEM micrographs. Here we demonstrate, for the first time, the mechanisms responsible for this e-beam-induced damage in OIHP thin films, which is precluding their detailed SEM-characterization and understanding. The e-beam-induced rapid volatilization of the organic species from the OIHP surface in the SEM results in localized shrinkage and buildup of tensile stresses. These stresses drive grain-boundaries cracking, resulting in a 'mud-cracking' pattern that is influenced by the thin-film grain size. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.