化学物理
卤化物
局部对称性
散射
分子动力学
钙钛矿(结构)
中子散射
凝聚态物理
材料科学
结晶学
化学
物理
光学
计算化学
无机化学
量子力学
作者
Nicholas J. Weadock,Tyler C. Sterling,Julian A. Vigil,Aryeh Gold‐Parker,Ian C. P. Smith,Ballal Ahammed,Matthew Krogstad,Feng Ye,David Voneshen,Peter Gehring,Andrew M. Rappe,Hans‐Georg Steinrück,Elif Ertekin,Hemamala I. Karunadasa,D. Reznik,Michael F. Toney
出处
期刊:Joule
[Elsevier]
日期:2023-05-01
卷期号:7 (5): 1051-1066
被引量:14
标识
DOI:10.1016/j.joule.2023.03.017
摘要
Hybrid lead-halide perovskites (LHPs) are semiconductors with novel properties that are distinctively governed by structural fluctuations. Diffraction experiments sensitive to long-range order reveal a cubic structure in the device-relevant, high-temperature phase. Local probes find additional short-range order with lower symmetry that may govern structure-function relationships. However, our understanding is impeded by unresolved dimensionality, participating atoms, and dynamics of short-range order. Here, we determine the true structure of two hybrid LHPs, CH3NH3PbI3 and CH3NH3PbBr3, using a combination of single-crystal diffuse scattering, neutron inelastic spectroscopy, and molecular dynamics simulations. The remarkable collective dynamics, not observed in previous studies, consist of a network of local, two-dimensional, circular regions of dynamically tilting lead-halide octahedra (lower symmetry) that induce longer-range intermolecular CH 3 NH 3 + correlations. The dynamic local structure may introduce transient ferroelectric or antiferroelectric domains that increase charge carrier lifetimes and strongly affect halide migration, a poorly understood degradation mechanism.
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