Pressure-Induced Structural and Optical Properties of Inorganic Halide Perovskite CsPbBr3.
Pressure-Induced Structural and Optical Properties of Inorganic Halide Perovskite CsPbBr3.
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DOI：
10.1021/acs.jpclett.7b01577
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发表时间：
2017-07
期刊：
影响因子：
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通讯作者：
Long Zhang;Qingxin Zeng;Kai Wang
中科院分区：
文献类型：
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作者：
Long Zhang;Qingxin Zeng;Kai Wang
超导光伏材料因其优异的光伏性能和广泛的实用性而受到人们的持续关注。本文讨论了CsPbBr_3在高压下的结构和光学性质的变化。随着压力的增加，带隙在1.0 GPa之前开始红移，随后是连续的蓝移，直到晶体完全非晶化。高压同步辐射X射线和拉曼光谱测定了1.2 GPa下的同构相变。这是由于PbBr6在高压下键长收缩和八面体畸变的结果。晶体的非晶化是由于PbBr6八面体的严重扭曲和倾斜，导致长程有序被破坏。光学性质的变化与晶体结构的演化密切相关。我们的讨论表明，高压研究可以作为一种有效的手段来调整全无机卤化物钙钛矿的结构和性能。
Perovskite photovoltaic materials are gaining sustained attention because of their excellent photovoltaic properties and extensive practical applicability. In this Letter, we discuss the changes in the structure and optical properties of CsPbBr3 under high pressure. As the pressure increased, the band gap initially began to red shift before 1.0 GPa followed by a continuous blue shift until the crystal was completely amorphized. An isostructural phase transition at 1.2 GPa was determined by high-pressure synchrotron X-ray and Raman spectroscopy. The result could be attributed to bond length shrinkage and PbBr6 octahedral distortion under high pressure. The amorphization of the crystal was due to the severe distortion and tilt of the PbBr6 octahedron, leading to broken long-range order. Changes in optical properties are closely related to the evolution of the crystal structure. Our discussion shows that high-pressure study can be used as an effective means to tune the structure and properties of all-inorganic halide perovskites.