气候变化领域集成服务门户(CCPortal): Mixed phononic and non-phononic transport in hybrid lead halide perovskites: Glass-crystal duality, dynamical disorder, and anharmonicity

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DOI	10.1039/c8ee02820f
	Mixed phononic and non-phononic transport in hybrid lead halide perovskites: Glass-crystal duality, dynamical disorder, and anharmonicity
	Zhu T.; Ertekin E.
发表日期	2019
ISSN	17545692
起始页码	216
结束页码	229
卷号	12 期号:1
英文摘要	In hybrid materials, a high-symmetry lattice is decorated by low-symmetry building blocks. The result is an aperiodic solid that hosts many nearly-degenerate disordered configurations. Using the perovskite methylammonium lead iodide (MAPbI 3 ) as a prototype hybrid material, we show that the inherent disorder renders the conventional phonon picture of transport insufficient. Ab initio molecular dynamics and analysis of the spectral energy density reveal that vibrational carriers simultaneously exhibit features of both classical phonons and of carriers typically found in glasses. The low frequency modes retain elements of acoustic waves but exhibit extremely short lifetimes of only a few tens of picoseconds. For higher frequency modes, strong scattering due to rapid motion and reconfiguration of the organic cation molecules induces a loss of definition of the wave vector. Lattice dynamics shows that these carriers are more akin to diffusons-the nonwave carriers in vitreous materials-and are the dominant contributors to thermal conduction near room temperature. To unify the framework of glassy diffusons with that of phonons scattered at the ultimate limit, three-phonon interactions resolved from first-principles expose anharmonic effects two orders of magnitude higher than in silicon. The dominant anharmonic interactions occur within modes of the PbI 6 octahedral framework itself, as well as between modes of the octahedral framework and modes localized to the MA molecules. The former arises from long-range interactions due to resonant bonding, and the latter from polar rotor scattering of the MA molecules. This establishes a clear microscopic connection between symmetry-breaking, dynamical disorder, anharmonicity, and the loss of wave nature in MAPbI 3 . © 2019 The Royal Society of Chemistry.
英文关键词	Crystal lattices; Glass; Hybrid materials; Layered semiconductors; Lead compounds; Molecular dynamics; Molecules; Perovskite; Phonons; Ab initio molecular dynamics; Anharmonic interaction; Long range interactions; Microscopic connections; Near room temperature; Octahedral frameworks; Phonon interactions; Spectral energy density; Iodine compounds; crystal; density; electron; energy; glass; halide; lead; perovskite; symmetry; thermal conductivity
语种	英语
来源期刊	Energy & Environmental Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/190038
作者单位	Department of Mechanical Science and Engineering and Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
推荐引用方式 GB/T 7714	Zhu T.,Ertekin E.. Mixed phononic and non-phononic transport in hybrid lead halide perovskites: Glass-crystal duality, dynamical disorder, and anharmonicity[J],2019,12(1).
APA	Zhu T.,&Ertekin E..(2019).Mixed phononic and non-phononic transport in hybrid lead halide perovskites: Glass-crystal duality, dynamical disorder, and anharmonicity.Energy & Environmental Science,12(1).
MLA	Zhu T.,et al."Mixed phononic and non-phononic transport in hybrid lead halide perovskites: Glass-crystal duality, dynamical disorder, and anharmonicity".Energy & Environmental Science 12.1(2019).