Celeste Anna, Girdzis Samuel P, Cladek Bernadette R, Deschene Christina R, Wolf Nathan R, Chapman Karena W, Karunadasa Hemamala I, Tucker Matthew G, Mao Wendy L, Lin Yu
Department of Earth and Planetary Sciences, Stanford University, Stanford, California, CA, USA.
Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California, CA, USA.
Nat Commun. 2025 Aug 16;16(1):7631. doi: 10.1038/s41467-025-62893-6.
The mechanisms governing pressure-induced amorphization and its reversibility in halide perovskites are not yet fully understood, particularly the contribution of local disorder. We performed high-pressure synchrotron total X-ray scattering and reverse Monte Carlo (RMC) big-box modeling using CsPbBr as a model system to investigate short-range structural evolution in both the ordered and partially amorphous phases. While diffraction data indicate that long-range order persists up to 2 GPa, pair distribution function (PDF) analysis reveals significant local distortions, including PbBr octahedral tilting and Cs displacement, which influence the bandgap through a complex interplay between bond compression and angular tilting. Beyond 2 GPa, CsPbBr undergoes partial amorphization, with significant disordering of Cs and Br, while the Pb sublattice remains preserved, allowing for structural recovery upon decompression. Our work, accounting for both short- and long-range structural evolution through RMC modeling, successfully captures how disorder shapes the structural response of halide perovskites under pressure.
卤化物钙钛矿中压力诱导非晶化及其可逆性的控制机制尚未完全理解，尤其是局部无序的作用。我们以CsPbBr为模型体系，进行了高压同步辐射全X射线散射和反向蒙特卡罗（RMC）大盒子建模，以研究有序相和部分非晶相中的短程结构演变。虽然衍射数据表明长程有序在高达2 GPa时仍然存在，但对分布函数（PDF）分析揭示了显著的局部畸变，包括PbBr八面体倾斜和Cs位移，它们通过键压缩和角度倾斜之间的复杂相互作用影响带隙。超过2 GPa后，CsPbBr发生部分非晶化，Cs和Br出现显著无序，而Pb亚晶格保持不变，使得减压后结构得以恢复。我们的工作通过RMC建模同时考虑了短程和长程结构演变，成功捕捉了无序如何塑造卤化物钙钛矿在压力下的结构响应。
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