Acoustic phonon lifetimes limit thermal transport in methylammonium lead iodide

Aryeh Gold-Parker, Peter M. Gehring, Jonathan M. Skelton, Ian C. Smith, Dan Parshall, Jarvist M. Frost, Hemamala I. Karunadasa, Aron Walsh, Michael F. Toney

Research output: Contribution to journalArticlepeer-review

30 Citations (Scopus)

Abstract

Hybrid organic–inorganic perovskites (HOIPs) have become an important class of semiconductors for solar cells and other optoelectronic applications. Electron–phonon coupling plays a critical role in all optoelectronic devices, and although the lattice dynamics and phonon frequencies of HOIPs have been well studied, little attention has been given to phonon lifetimes. We report high-precision momentum-resolved measurements of acoustic phonon lifetimes in the hybrid perovskite methylammonium lead iodide (MAPI), using inelastic neutron spectroscopy to provide high-energy resolution and fully deuterated single crystals to reduce incoherent scattering from hydrogen. Our measurements reveal extremely short lifetimes on the order of picoseconds, corresponding to nanometer mean free paths and demonstrating that acoustic phonons are unable to dissipate heat efficiently. Lattice-dynamics calculations using ab initio third-order perturbation theory indicate that the short lifetimes stem from strong three-phonon interactions and a high density of low-energy optical phonon modes related to the degrees of freedom of the organic cation. Such short lifetimes have significant implications for electron–phonon coupling in MAPI and other HOIPs, with direct impacts on optoelectronic devices both in the cooling of hot carriers and in the transport and recombination of band edge carriers. These findings illustrate a fundamental difference between HOIPs and conventional photovoltaic semiconductors and demonstrate the importance of understanding lattice dynamics in the effort to develop metal halide perovskite optoelectronic devices.

Original languageEnglish
Pages (from-to)11905-11910
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume115
Issue number47
DOIs
Publication statusPublished - 2018 Nov 20

Bibliographical note

Funding Information:
e thank Hans-Georg Steinrück, Matthew Beard, and Aaron Lindenberg for helpful discussions. A.G.-P. thanks Craig Brown for assistance with planning neutron scattering measurements. A.G.-P. was supported by NSF Graduate Research Fellowship Program Grant DGE-1147470 and by the Hybrid Perovskite Solar Cell program of the National Center for Photovoltaics funded by the US Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy. Use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, is supported by the US DOE, Office of Science, Office of Basic Energy Sciences under Contract DE-AC02-76SF00515. This research was supported by Engineering and Physical Sciences Research Council (EPSRC) Grant EP/K016288/1, the Royal Society, and the Leverhulme Trust. Via our membership in the High-End Computing Materials Chemistry Consortium, which is funded by EPSRC Grant EP/L000202, this work used the ARCHER UK National Supercomputing Service. We also made use of the Balena High Performance Computing facility at the University of Bath, which is maintained by Bath University Computing Services. Work by I.C.S. and H.I.K. was funded by the DOE, Laboratory Directed Research and Development program at SLAC National Accelerator Laboratory (Grant DE-AC02-76SF00515).

Funding Information:
ACKNOWLEDGMENTS. We thank Hans-Georg Steinrück, Matthew Beard, and Aaron Lindenberg for helpful discussions. A.G.-P. thanks Craig Brown for assistance with planning neutron scattering measurements. A.G.-P. was supported by NSF Graduate Research Fellowship Program Grant DGE-1147470 and by the Hybrid Perovskite Solar Cell program of the National Center for Photovoltaics funded by the US Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy. Use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, is supported by the US DOE, Office of Science, Office of Basic Energy Sciences under Contract DE-AC02-76SF00515. This research was supported by Engineering and Physical Sciences Research Council (EPSRC) Grant EP/K016288/1, the Royal Society, and the Leverhulme Trust. Via our membership in the High-End Computing Materials Chemistry Consortium, which is funded by EPSRC Grant EP/L000202, this work used the ARCHER UK National Supercomputing Service. We also made use of the Balena High Performance Computing facility at the University of Bath, which is maintained by Bath University Computing Services. Work by I.C.S. and H.I.K. was funded by the DOE, Laboratory Directed Research and Development program at SLAC National Accelerator Laboratory (Grant DE-AC02-76SF00515).

All Science Journal Classification (ASJC) codes

  • General

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