Nat. Commun.: In situ Imaging of the Atomic Phase Transition Dynamics in Metal Halide Perovskites

Title：

In situ Imaging of the Atomic Phase Transition Dynamics in Metal Halide Perovskites

Authors：

Mengmeng Ma^1,2, Xuliang Zhang^1,2, Xiao Chen³, Hao Xiong³, Liang Xu^1,2, Tao Cheng^1,2, Jianyu Yuan^1,2, Fei Wei³, Boyuan Shen^1,2*

Institutions：

¹Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, 215123, Jiangsu, PR China.

²Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou, 215123, Jiangsu, PR China.

³Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing, 100084, PR China.

Abstract：

Phase transition dynamics are an important concern in the wide applications of metal halide perovskites, which fundamentally determine the optoelectronic properties and stabilities of perovskite materials and devices. However, a more in-depth understanding of such a phase transition process with real atomic resolution is still limited by the immature low-dose electron microscopy and in situ imaging studies to date. Here, we apply an emergent low-dose imaging technique to identify different phase structures (α, β and γ) in CsPbI₃ nanocrystals during an in-situ heating process. The rotation angles of PbI₆ octahedrons can be measured in these images to quantitatively describe the thermal-induced phase distribution and phase transition. Then, the dynamics of such a phase transition are studied at a macro time scale by continuously imaging the phase distribution in a single nanocrystal. The structural evolution process of CsPbI₃ nanocrystals at the particle level, including the changes in morphology and composition, is also visualized with increasing temperature. These results provide atomic insights into the transition dynamics of perovskite phases, indicating a long-time transition process with obvious intermediate states and spatial distribution that should be generally considered in the further study of structure-property relations and device performance.

IF：

17.694

Link：

https://doi.org/10.1038/s41467-023-42999-5