Modelization of charge carriers mobilities in halide perovskites: Fr\"ohlich scattering and quantum localization effects in a dynamic disorder regime

TL;DR

This study models charge transport in MAPbI3, revealing how Fr"ohlich scattering and dynamic disorder influence mobility and localization, which are key to understanding its electronic properties.

Contribution

It introduces a tight-binding model that captures the effects of Fr"ohlich interaction and dynamic disorder on charge carrier mobility and localization in MAPbI3.

Findings

Charge mobility limited to ~200 cm²/Vs at room temperature.

Dynamic disorder breaks localization of states at band edges.

Lattice vibrations significantly influence charge diffusion.

Abstract

We analyze the quantum transport properties of MAPbI3 within a tight-binding model. Charge carriers are strongly scattered by the Fr\"ohlich interaction with longitudinal optical phonon modes. This limits their mobilities at room temperature to the order of 200 cm$^2$/Vs. In the presence of additional extrinsic disorder the mobility decreases and a large fraction of the electronic states at band edges can be localized. These states would be insulating if the lattice were static, but their localization is broken by the dynamic disorder induced by the vibrations of the longitudinal optical modes. This process of electrons and holes diffusion, driven by the lattice dynamics, contributes to the unique electronic properties of this material.