Abstract
The formation of polarons due to the interaction between charge carriers and lattice ions has been proposed to have wide-ranging effects on charge carrier dynamics in lead halide perovskites. The hypothesis underlying many of those proposals is that charge carriers are ‘protected’ from scattering by their incorporation into large polarons. Following the approach of Kadanoff for scattering due to polar optical phonons, we derive expressions for the rates of scattering of polarons by acoustic phonons and ionized impurities, and compute the energy and angular dependent rates for electrons and holes in MAPbI3, MAPbBr3, and CsPbI3. We then use the ensemble Monte Carlo method to compute polaron distribution functions which satisfy a Boltzmann transport equation incorporating the same three scattering mechanisms, from which we extract mobilities for temperatures in the range 50–500 K. A comparison of the results with those of analogous calculations for bare band carriers indicates that polaronic effects on the scattering and mobilities of charge carriers in lead halide perovskites are more limited than has been suggested in some parts of the recent literature.
| Original language | English |
|---|---|
| Article number | L220305 |
| Journal | Physical Review B |
| Volume | 103 |
| Issue number | 22 |
| DOIs | |
| Publication status | Published - 1 Jun 2021 |
Funding
This work was funded by the United Kingdom's Engineering and Physical Sciences Research Council (EPSRC) through the Centre for Doctoral Training in New and Sustainable Photovoltaics (Grant Reference: EP/L01551X/1), and by the European Commission through the Horizon 2020 Framework Programme for Research and Innovation, Energy Oriented Centre of Excellence (EoCoE-II) project (Grant Agreement ID: 824158). We thank Prof. L. M. Peter for reading and commenting on an earlier draft of the Letter.