Synthesis of Edge-Shared Octahedral MAPbBr3 via Pressure- and Temperature-Induced Multiple-Stage Processes

作者：Mei Li, Kejun Bu, Junlong Li, Hao Wang, Yixuan Xu, Songhao Guo, Hui Luo, Bingyan Liu, Dongliang Yang, Yu Gong, Yonggang Wang, Yufeng Liu, Xujie Lü, Chuanlong Lin · 发表于：Chemistry of Materials · 年份：2023 · DOI：10.1021/acs.chemmater.2c03172 · 被引用次数：11 · 研究领域：Perovskite Materials and Applications、Solid-state spectroscopy and crystallography、2D Materials and Applications

Organic–inorganic halide perovskites possess flexible structures with tunable optical properties at high pressures, but the pressure-induced amorphization limits the understanding and exploration of the structure–property relationships. Herein, we report an edge-shared octahedral MAPbBr 3 via multiple-stage transformation of the traditional corner-shared three-dimensional perovskites at high-pressure and high-temperature ( P – T ) conditions. In situ synchrotron X-ray diffraction reveals that upon heating at 8.7 GPa, the amorphized MAPbBr 3 transforms into a high P – T structure above 654 K via multiple-stage crystallization. The high P – T phase is determined to be a monoclinic P 2/ m structure with layered edge-shared Pb–Br octahedra, which can be quenched to RT at high pressures but converts back to the initial cubic perovskite structure below 0.7 GPa under decompression. The Raman and optical measurements demonstrate that the high P – T phase has similar vibrational behavior and tunable optical properties to those of the pressure-induced amorphous phase, indicating the similarity in the local structure with the edge-shared PbBr 6 octahedral frame and the MA organic cations between the high P – T phase and the amorphous state. The present results demonstrate the structural diversity and interconversion in MAPbBr 3 by overcoming the large kinetic barrier derived from the anisotropic organic cations and disordering arrangement of the Pb–Br octahedra, providing new insights i...