Pols Mike, Brocks Geert, Calero Sofía, Tao Shuxia
Materials Simulation & Modelling, Department of Applied Physics and Science Education, Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands.
Computational Chemical Physics, Faculty of Science and Technology and MESA+ Institute for Nanotechnology, University of Twente, 7500 AE Enschede, Netherlands.
J Phys Chem Lett. 2024 Aug 8;15(31):8057-8064. doi: 10.1021/acs.jpclett.4c01629. Epub 2024 Jul 31.
With the use of chiral organic cations in two-dimensional metal halide perovskites, chirality can be induced in the metal halide layers, which results in semiconductors with intriguing chiral optical and spin-selective transport properties. The chiral properties strongly depend upon the temperature, despite the basic crystal symmetry not changing fundamentally. We identify a set of descriptors that characterize the chirality of metal halide perovskites, such as MBAPbI, and study their temperature dependence using molecular dynamics simulations with on-the-fly machine-learning force fields obtained from density functional theory calculations. We find that, whereas the arrangement of organic cations remains chiral upon increasing the temperature, the inorganic framework loses this property more rapidly. We ascribe this to the breaking of hydrogen bonds that link the organic with the inorganic substructures, which leads to a loss of chirality transfer.
通过在二维金属卤化物钙钛矿中使用手性有机阳离子，可以在金属卤化物层中诱导手性，这导致半导体具有有趣的手性光学和自旋选择性传输特性。尽管基本晶体对称性没有根本改变，但手性特性强烈依赖于温度。我们确定了一组表征金属卤化物钙钛矿（如MBAPbI）手性的描述符，并使用从密度泛函理论计算获得的实时机器学习力场的分子动力学模拟研究它们的温度依赖性。我们发现，虽然有机阳离子的排列在温度升高时仍保持手性，但无机骨架更快地失去了这种特性。我们将此归因于连接有机和无机子结构的氢键的断裂，这导致了手性转移的丧失。
