Lone-Pair Stereochemistry Induces Ferroelectric Distortion and the Rashba Effect in Inorganic Halide Perovskites,Chemistry of Materials

当前位置： X-MOL 学术 › Chem. Mater. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Lone-Pair Stereochemistry Induces Ferroelectric Distortion and the Rashba Effect in Inorganic Halide Perovskites
Chemistry of Materials ( IF 7.2 ) Pub Date : 2023-11-01 , DOI: 10.1021/acs.chemmater.3c02201
Michael W. Swift ₁ , John L. Lyons ₁

Affiliation

The lone-pair s states of germanium, tin, and lead underlie many of the unconventional properties of inorganic metal halide perovskites. Dynamic stereochemical expression of the lone pairs is well established for perovskites based on all three metals, but previously, only the germanium perovskites were thought to express the lone pair crystallographically. In this work, we use advanced first-principles calculations with a hybrid functional and spin–orbit coupling to predict stable monoclinic polar phases of CsSnI₃ and CsSnBr₃, which exhibit a ferroelectric distortion driven by stereochemical expression of the tin lone pair. We also predict similar metastable ferroelectric phases of CsPbI₃ and CsPbBr₃. In addition to ferroelectricity, these phases exhibit the Rashba effect. Spin splitting in both the conduction and valence bands suggests that nanostructures based on these phases could host bright ground-state excitons. Finally, we discuss paths toward experimental realization of these phases via electric fields and tensile strain.

中文翻译：

无机卤化物钙钛矿中的孤对立体化学诱导铁电畸变和 Rashba 效应

锗、锡和铅的孤对电子态是无机金属卤化物钙钛矿许多非常规特性的基础。基于所有三种金属的钙钛矿的孤对电子的动态立体化学表达已经得到很好的建立，但以前，只有锗钙钛矿被认为能够在晶体学上表达孤电子对。在这项工作中，我们使用混合泛函和自旋轨道耦合的先进第一原理计算来预测 CsSnI ₃和 CsSnBr ₃的稳定单斜极性相，它们表现出由锡孤电子对的立体化学表达驱动的铁电畸变。我们还预测了 CsPbI ₃和 CsPbBr ₃类似的亚稳态铁电相。除了铁电性之外，这些相还表现出拉什巴效应。导带和价带中的自旋分裂表明基于这些相的纳米结构可以容纳明亮的基态激子。最后，我们讨论了通过电场和拉伸应变实验实现这些阶段的路径。

更新日期：2023-11-01

点击分享查看原文

点击收藏

公开下载

阅读更多本刊新发论文本刊介绍/投稿指南