State Key Laboratory of Superhard Materials, Jilin University, Changchun, 130012, P.R. China.
Institute of Atomic and Molecular Physics, Jilin University, Changchun, 130012, P.R. China.
ChemSusChem. 2019 Sep 6;12(17):3971-3976. doi: 10.1002/cssc.201901388. Epub 2019 Jul 30.
Among photovoltaic materials, the antimony-based, perovskite-like structure Cs Sb I stands out owing to its low toxicity and air stability. Here, changes in the optoelectronic properties and crystal structure of the lead-free perovskite derivative Cs Sb I are reported, caused by pressure-induced lattice compression. At 20.0 GPa, Cs Sb I with a wide band gap (2.34 eV) successfully broke through the Shockley-Queisser limit (1.34 eV), accompanied by clear piezochromism from orange-yellow to opaque black. Additionally, Cs Sb I experienced completely reversible amorphization at 20.0 GPa. These optical changes could be attributed to atomic-orbital overlap enhancement caused by contraction of the Sb-I bond length and diminution of the Sb-I bond angle. In addition, Cs Sb I underwent a transition from semiconductor to conductor upon compression and obtained metallic properties at 44.3 GPa, indicating new electronic properties. The obtained results may further broaden the research prospects of halide perovskite materials in the field of photovoltaics.
在光伏材料中，基于锑的类钙钛矿结构 Cs Sb I 由于其低毒性和空气稳定性而脱颖而出。本文报道了由压力诱导的晶格压缩引起的无铅钙钛矿衍生物 Cs Sb I 的光电性质和晶体结构的变化。在 20.0 GPa 时，具有宽能隙（2.34 eV）的 Cs Sb I 成功突破了肖克利-奎塞尔限制（1.34 eV），同时伴随着明显的从橙黄色到不透明黑色的压致变色。此外，Cs Sb I 在 20.0 GPa 时经历了完全可逆的非晶化。这些光学变化可归因于 Sb-I 键长收缩和 Sb-I 键角减小导致的原子轨道重叠增强。此外，Cs Sb I 在压缩过程中从半导体转变为导体，并在 44.3 GPa 时获得了金属性质，表明了新的电子性质。这些结果可能会进一步拓宽卤化物钙钛矿材料在光伏领域的研究前景。
