Lattice Thermal Conductivity of Organic-Inorganic Hybrid Perovskite CH3NH3PbI3

TL;DR

This study investigates the lattice thermal conductivity of hybrid perovskite CH3NH3PbI3 using molecular dynamics simulations, revealing phase-dependent thermal properties crucial for device stability.

Contribution

It provides the first detailed temperature-dependent thermal conductivity data for CH3NH3PbI3, highlighting phase effects and underlying phonon dynamics.

Findings

Low thermal conductivity in tetragonal phase (0.50 W/mK) at room temperature.

Higher thermal conductivity in pseudocubic phase (1.80 W/mK at 330 K).

Low group velocity and anharmonicity cause low thermal conductivity.

Abstract

Great success has been achieved in improving the photovoltaic energy conversion efficiency of the organic-inorganic perovskite-based solar cells, but with very limited knowledge on the thermal transport in hybrid perovskites, which would affect the device lifetime and stability. Based on the potential developed from the density functional theory calculations, we studied the lattice thermal conductivity of the hybrid halide perovskite CH3NH3PbI3 using equilibrium molecular dynamics simulations. Temperature-dependent thermal conductivity is reported from 160 K to 400 K, which covers the tetragonal phase (160-330 K) and the pseudocubic phase (>330K). A very low thermal conductivity (0.50 W/mK) is found in the tetragonal phase at room temperature, whereas a much higher thermal conductivity is found in the pseudocubic phase (1.80 W/mK at 330 K). The low group velocity of acoustic phonons and the strong anharmonicity are found responsible for the relatively low thermal conductivity of the tetragonal CH3NH3PbI3.