Dr. Yuan Biao, a postdoctoral researcher, and Professor Han Yu of South China University of Technology (SCUT) published a co-authored study titled “Atomically resolved edges and defects in lead halide perovskites” in Nature. The research team obtained, for the first time, atomic-resolution imaging of the edge and defect structures in methylammonium lead iodide (MAPbI3) hybrid perovskite crystal, and revealed their dynamic structural damage mechanisms under electron beam irradiation.

Using an event-driven direct-detection electron detector, the team collected data under ultralow electron dose conditions. Through advanced electron ptychography, they completed high spatiotemporal resolution real-space structural analysis of MAPbI3. The results revealed that the majority of edges of this material are terminated by methylammonium (MA⁺) and iodide (I⁻). Moreover, I vacancies were identified as the key defects driving structural degradation—whether on the surface or within the material, they markedly accelerated the evolution of crystal damage. This study not only provided direct evidence that can deepen the understanding of the microscopic instability mechanisms of hybrid perovskites, but also demonstrated significant potential and methodological value of ultralow-dose atomic imaging for investigating electron-beam-sensitive materials.