| Affiliation: | 1. AI for Science Institute, Chengfu Street, Beijing, 100083 China;2. Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, Youyi Street, Xi'an, Shannxi, 710072 China;3. AI for Science Institute, Chengfu Street, Beijing, 100083 China DP Technology, Haidian East Third Street, Beijing, 100080 China;4. Fujian Science & Technology Innovation Laboratory for Energy Devices of China, Xingang Street, Ningde, Fujian, 352100 China;5. Key Laboratory of Magnetic Materials Devices & Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Zhongguanxi Street, Ningbo, Zhejiang, 315201 China |
| Abstract: | In hybrid perovskites, the organic molecules and inorganic frameworks exhibit distinct static and dynamic characteristics. Their coupling will lead to fascinating phenomena, such as large polarons, dynamic Rashba–Dresselhaus effects, etc. In this paper, deep potential molecular dynamics (DPMD) is employed, a large-scale MD simulation scheme with DFT accuracy, to study hybrid perovskites formamidinium lead iodide (FAPbI3) and methylamonium lead iodide (MAPbI3). A spontaneous hybrid nano-domain behavior, namely multiple molecular rotation nano-domains embedded into a single [PbI6]4− octahedra rotation domain, is first discovered at low temperatures. The behavior originates from the interplay between the long range order of molecular rotation and local lattice deformation, and clarifies the puzzling structural features of FAPbI3 at low temperatures. The work provides new insights into the structural characteristics and stability of hybrid perovskite, as well as new ideas for the structural characterization of organic–inorganic coupled systems. |
