Frost, Jarvist Moore, Whalley, Lucy and Walsh, Aron (2017) Slow Cooling of Hot Polarons in Halide Perovskite Solar Cells. ACS Energy Letters, 2 (12). pp. 2647-2652. ISSN 2380-8195
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Abstract
Halide perovskites show unusual thermalization kinetics for above-bandgap photoexcitation. We explain this as a consequence of excess energy being deposited into discrete large polaron states. The crossover between low-fluence and high-fluence “phonon bottleneck” cooling is due to a Mott transition where the polarons overlap (n ≥ 1018 cm–3) and the phonon subpopulations are shared. We calculate the initial rate of cooling (thermalization) from the scattering time in the Fröhlich polaron model to be 78 meV ps–1 for CH3NH3PbI3. This rapid initial thermalization involves heat transfer into optical phonon modes coupled by a polar dielectric interaction. Further cooling to equilibrium over hundreds of picoseconds is limited by the ultralow thermal conductivity of the perovskite lattice.
Item Type: | Article |
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Subjects: | F100 Chemistry F200 Materials Science F300 Physics H800 Chemical, Process and Energy Engineering |
Department: | Faculties > Engineering and Environment > Mathematics, Physics and Electrical Engineering |
Depositing User: | Elena Carlaw |
Date Deposited: | 23 Jun 2020 11:34 |
Last Modified: | 31 Jul 2021 11:32 |
URI: | http://nrl.northumbria.ac.uk/id/eprint/43553 |
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