Atomic Resolution Imaging of Halide Perovskites

Abstract

The radiation-sensitive nature of halide perovskites has hindered structural studies at the atomic scale. We overcome this obstacle by applying low dose-rate in-line holography, which combines aberration-corrected high-resolution transmission electron microscopy with exit-wave reconstruction. This technique successfully yields the genuine atomic structure of ultrathin two-dimensional CsPbBr halide perovskites, and a quantitative structure determination was achieved atom column by atom column using the phase information of the reconstructed exit-wave function without causing electron beam-induced sample alterations. An extraordinarily high image quality enables an unambiguous structural analysis of coexisting high-temperature and low-temperature phases of CsPbBr in single particles. On a broader level, our approach offers unprecedented opportunities to better understand halide perovskites at the atomic level as well as other radiation-sensitive materials.

CsPbBr3 QD/AlOx Inorganic Nanocomposites with Exceptional Stability in Water, Light, and Heat

“…High-resolution STEM-HAADF imaging was also performed on single QDs after five ALD cycles ( Figure 1B). [27] No change in the lattice parameters (5.7 )was observed compared with the reported values for CsPbBr 3 QDs. [27] No change in the lattice parameters (5.7 )was observed compared with the reported values for CsPbBr 3 QDs.…”

Recent Progress of All‐Bromide Inorganic Perovskite Solar Cells

“…Furthermore, theoretical investigations of point defects and grain boundary‐induced trap states in CsPbBr 3 were reported to lead to shallow trap states within the bandgap demonstrating the superior electronic properties or defect‐tolerance property of CsPbBr 3 . Experimentally, efforts have been made to characterize the grain boundaries in CsPbBr 3 by electron microscopy techniques . For example, Mishra et al determined the atomic structures of grain boundaries in CsPbBr 3 perovskite nanocrystals by scanning transmission electron microscopy‐–annular dark field (STEM‐HAADF) imaging combined with DFT modeling .…”

In Situ Transmission Electron Microscopy Study of Electron Beam-Induced Transformations in Colloidal Cesium Lead Halide Perovskite Nanocrystals

“…Some of these reports indicated that the particles are made of metallic lead, 11,13,16,17 a claim that is supported by the evidence that Pb 2+ species from various material systems can be reduced to Pb 0 by irradiation with electrons 18 or with X-rays. 8,19 Other studies of irradiation of APbX 3 NCs have suggested that PbBr 2 11 is also formed.…”