Imperial College London
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Dr Jarvist Moore Frost

Faculty of Natural Sciences, Department of Chemistry

Royal Society URF (Lecturer)
 
 
 
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Contact

 

jarvist.frost Website

 
 
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Location

 

601FMolecular Sciences Research HubWhite City Campus

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Summary

 

Publications

Citation

BibTex format

@article{Frost:2017:10.1103/PhysRevB.96.195202,
author = {Frost, JM},
doi = {10.1103/PhysRevB.96.195202},
journal = {Physical Review B},
title = {Calculating polaron mobility in halide perovskites},
url = {http://dx.doi.org/10.1103/PhysRevB.96.195202},
volume = {96},
year = {2017}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Lead halide perovskite semiconductors are soft, polar materials. The strong driving force for polaron formation (the dielectric electron-phonon coupling) is balanced by the light band effective masses, leading to a strongly-interacting large polaron. A first-principles prediction of mobility would help understand the fundamental mobility limits. Theories of mobility need to consider the polaron (rather than free-carrier) state due to the strong interactions. In this material we expect that at room temperature polar-optical phonon mode scattering will dominate and so limit mobility. We calculate the temperature-dependent polaron mobility of hybrid halide perovskites by variationally solving the Feynman polaron model with the finite-temperature free energies of saka. This model considers a simplified effective-mass band structure interacting with a continuum dielectric of characteristic response frequency. We parametrize the model fully from electronic-structure calculations. In methylammonium lead iodide at 300K we predict electron and hole mobilities of 133 and 94cm2V-1s-1, respectively. These are in acceptable agreement with single-crystal measurements, suggesting that the intrinsic limit of the polaron charge carrier state has been reached. Repercussions for hot-electron photoexcited states are discussed. As well as mobility, the model also exposes the dynamic structure of the polaron. This can be used to interpret impedance measurements of the charge-carrier state. We provide the phonon-drag mass renormalization and scattering time constants. These could be used as parameters for larger-scale device models and band-structure dependent mobility simulations.
AU  - Frost,JM
DO  - 10.1103/PhysRevB.96.195202
PY  - 2017///
SN  - 2469-9950
TI  - Calculating polaron mobility in halide perovskites
T2  - Physical Review B
UR  - http://dx.doi.org/10.1103/PhysRevB.96.195202
VL  - 96
ER  -
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