Common acoustic phonon lifetimes in inorganic and hybrid lead halide perovskites
| Autor: | Guangyong Xu, N. Giles-Donovan, William Ratcliff, Mark Green, Peter M. Gehring, Sandy Cochran, J. L. Minns, Zuo-Guang Ye, W. van Beek, M. Songvilay, Maryam Bari, Chris Stock, Karin Schmalzl, Dmitry Chernyshov, Craig M. Brown |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Condensed Matter - Materials Science
Materials science Physics and Astronomy (miscellaneous) Phonon Neutron diffraction Center (category theory) Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Molecular physics Article cond-mat.mtrl-sci Momentum Brillouin zone Condensed Matter::Materials Science Thermal conductivity 0103 physical sciences ddc:530 General Materials Science 010306 general physics 0210 nano-technology Anisotropy Energy (signal processing) |
| Zdroj: | Songvilay, M, Giles-Donovan, N, Bari, M, Ye, Z-G, Minns, J L, Green, M A, Xu, G, Gehring, P M, Schmalzl, K, Ratcliff, W D, Brown, C M, Chernyshov, D, Beek, W V, Cochran, S & Stock, C 2019, ' Common acoustic phonon lifetimes in inorganic and hybrid lead halide perovskites ', Physical Review Materials, vol. 3, no. 9, 093602 . https://doi.org/10.1103/PhysRevMaterials.3.093602 Phys Rev Mater Physical review materials 3, 093602 (2019). doi:10.1103/PhysRevMaterials.3.093602 |
| Popis: | The acoustic phonons in the organic-inorganic lead halide perovskites have been reported to have anomalously short lifetimes over a large part of the Brillouin zone. The resulting shortened mean free paths of the phonons have been implicated as the origin of the low thermal conductivity. We apply neutron spectroscopy to show that the same acoustic phonon energy linewidth broadening (corresponding to shortened lifetimes) occurs in the fully inorganic ${\mathrm{CsPbBr}}_{3}$ by comparing the results on the organic-inorganic ${\mathrm{CH}}_{3}{\mathrm{NH}}_{3}{\mathrm{PbCl}}_{3}$. We investigate the critical dynamics near the three zone boundaries of the cubic $Pm\overline{3}m$ Brillouin zone of ${\mathrm{CsPbBr}}_{3}$ and find energy and momentum broadened dynamics at momentum points where the Cs-site ($A$-site) motions contribute to the cross section. Neutron diffraction is used to confirm that both the Cs and Br sites have unusually large thermal displacements with an anisotropy that mirrors the low temperature structural distortions. The presence of an organic molecule is not necessary to disrupt the low-energy acoustic phonons at momentum transfers located away from the zone center in the lead halide perovskites and such damping may be driven by the large displacements or possibly disorder on the $A$ site. |
| Databáze: | OpenAIRE |
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