Phonon anharmonicity, lifetimes and thermal transport in CH$_3$NH$_3$PbI$_3$ from many-body perturbation theory

TL;DR

This study uses many-body perturbation theory to analyze phonon anharmonicity, lifetimes, and thermal transport in CH$_3$NH$_3$PbI$_3$, revealing strong lattice interactions and implications for device applications.

Contribution

It provides a first-principles analysis of phonon anharmonicity and thermal transport in hybrid perovskites, highlighting their distinct vibrational properties compared to inorganic semiconductors.

Findings

Strong phonon anharmonicity with short lifetimes

Distinct phonon behavior from GaAs and CdTe

Implications for thermal conductivity and charge transport

Abstract

Lattice vibrations in CH$_3$NH$_3$PbI$_3$ are strongly interacting, with double well instabilities present at the Brillouin zone boundary. Analysis within a first-principles lattice dynamics framework reveals anharmonic potentials with short phonon quasi-particle lifetimes and mean-free paths. The phonon behaviour is distinct from the inorganic semiconductors GaAs and CdTe where three-phonon interaction strengths are three orders of magnitude smaller. The implications for the applications of hybrid halide perovskites arising from thermal conductivity, band-gap deformation, and charge-carrier scattering through electron-phonon coupling, are presented.