fig7

Figure 7. (A) HRTEM image and SAED pattern of MAPbI₃ before heating under vacuum; (B) HRTEM image and SED pattern of MAPbI₃ after heating at 85 °C for 400 s under vacuum; (C) HRTEM image and SED pattern of an individual MAPbI₃ showing the heat-induced degradation process under a dry air atmosphere. Reproduced with the permission of Ref.^[119] Copyright © 2017 Elsevier; (D) In situ liquid-cell TEM monitoring the transformation of MAPbI₃ to MAPbI₃·H₂O and PbI₂ (top line), as well as the dissolution of MAPbI₃·H₂O and subsequent recrystallization into PbI₂ (bottom line). Reproduced with the permission of Ref.^[120] Copyright © 2021 John Wiley & Sons. HRTEM :High-resolution TEM; TEM: Transmission electron microscopy; SAED: Selected area electron diffraction; SED: Scanning ED; ED: Electron diffraction.