fig3

Figure 3. (A) The degradation process of CsPbBr₃ nanosheets when exposed to electron beam irradiation. The perspective shown is along the [001] orientation. Reproduced with the permission of Ref.^[56] Copyright © 2017 American Chemical Society; (B) Phase segregation behavior of CsPb(Br_0.8I_0.2)₃ perovskite under beam irradiation is demonstrated through the HRTEM image and the corresponding FFT pattern. After exposure to an excess electron beam dose of 1140 e Å^-2, the formation of Pb nanoparticles is observed. Reproduced with the permission of Ref.^[99] Copyright © 2020 American Chemical Society; (C) HRTEM images with increased doses during the degradation into PbI₂ show the atomic scale images of the decomposition pathway. Reproduced with the permission of Ref.^[39] Copyright © 2021 Springer Nature. FFT: Fast fourier transform; HRTEM :High-resolution TEM; TEM: Transmission electron microscopy.