We establish that ultralow lattice thermal conductivity in halide perovskites and related octahedral framework materials arises from two distinct and complementary mechanisms: (i) halogen-halogen-enabled rotational soft modes that reshape the low-frequency spectrum and intensify phonon scattering, and (ii) static octahedral distortions that further enhance anharmonicity and reduce phonon lifetimes. Using first-principles calculations on CsPbBr3, we demonstrate that Br-Br interactions induce rotational soft modes that decongest the phonon spectrum and enhance three- and four-phonon scattering, strongly suppressing particle-like thermal conductivity (kappa_p). Independently, static octahedral distortions further reduce kappa_p by amplifying anharmonicity while leaving wave-like conductivity (kappa_c) intact. Based on these mechanistic insights, we introduce a geometric distortion factor rho and perform a high-throughput screening that first selects materials with halogen-coordinated octahedral building blocks-ensuring the presence of rotational soft modes-and then identifies those with pronounced distortion. This strategy uncovers TaGaI8 with an ultralow kappa_L = 0.11 W/mK at room temperature. This work establishes halogen-halogen-enabled rotational soft modes and octahedral distortions as transferable design principles for octahedra-containing halides, spanning both extended frameworks and molecular-cluster motifs, for discovering ultralow-kappa_L materials.
Accelerated Discovery of Crystalline Materials with Record Ultralow Lattice Thermal Conductivity via a Universal Descriptor
Northwestern Polytechnical University（西北工业大学）；CRISMAT, CNRS, Normandie Univ, ENSICAEN, UNICAEN（诺曼底大学，卡昂国立高等工程学院，法国国家科学研究中心材料研究化学实验室）；Thayer School of Engineering, Dartmouth College（达特茅斯学院塔克工程学院）；Institute Laue Langevin（朗之万研究所）；FZU - Institute of Physics of the Czech Academy of Sciences（捷克科学院物理研究所）；ShanghaiTech Laboratory for Topological Physics & School of Physical Science and Technology, ShanghaiTech University（上海科技大学物理科学与技术学院拓扑物理实验室）；Université de Lorraine, CNRS, IJL（洛林大学，法国国家科学研究中心，界面与层析实验室）
Manifestation of the thermoelectric properties in Ge-based halide perovskites
尽管硫族化合物作为传统的热电材料已经得到了广泛的研究，但寻找一种具有高电导率和低热导率的合适材料仍然是一个挑战。在这项工作中，我们介绍了一类新的热电材料，锗基无机卤化物钙钛矿\ce{CsGeX3}（X = I，Br，Cl），这已经被认为是一个有前途的候选人的光伏应用。通过晶格动力学计算和Boltzmann输运方程的求解，我们发现这些钙钛矿具有低于0.18 W m $^{-1}$ K $^{-1}$的超低热导率，而具有高于860 cm $^2$ V $^{-1}$ s $^{-1}$的非常高的载流子迁移率，这远远优于传统的硫属化合物的热电性。这些结果为寻找高性能、低成本的无机卤化物钙钛矿基热电材料指明了方向。
Thermal history controls the optoelectronic response of lead halide perovskites through structure and dynamics
University of Cambridge（剑桥大学）；Imperial College London（伦敦帝国理工学院）；Ulsan National Institute of Science and Technology (UNIST)（蔚山科学技术院）；Linköping University（林雪平大学）；Chalmers University of Technology（查尔姆斯理工大学）；Helmholtz-Zentrum Berlin für Materialien und Energie（柏林亥姆霍兹材料与能源中心）；University of Oxford（牛津大学）
Distorted polyhedral architecture enabled high thermoelectric performance of columnar double halide perovskites Cs2AgPdCl5 and Cs2AgPtCl5
Jamia Millia Islamia（贾米阿米利娅伊斯兰大学）；Govt Naveen College（政府纳文学院）；Indian Institute of Technology, Jodhpur（印度理工学院乔德普尔分校）；University of Ulsan（蔚山大学）；Mody University of Science and Technology（莫迪科学与技术大学）
Band-like Carriers in a Soft, Anharmonic Lattice: Lead-Halide Perovskites
Pohang Accelerator Laboratory, POSTECH（浦项加速器实验室，浦项科技大学）；YUHS-KRIBB Medical Convergence Research Institute, College of Medicine, Yonsei University（延世大学医学院佑山-韩国生命科学研究院医学融合研究所）；Department of Physics, University of Seoul（首尔大学物理系）；Global Institute of Future Technology, Shanghai Jiao Tong University（上海交通大学未来技术学院）
Ligand-Controlled Phonon Dynamics in CsPbBr3 Nanocrystals Revealed by Machine-Learned Interatomic Potentials
Georgia Institute of Technology（佐治亚理工学院）；Queens College, City University of New York（纽约市立大学皇后学院）；The Graduate Center, City University of New York（纽约市立大学研究生中心）
