Understanding anharmonicity in hybrid lead halide perovskites from molecular dynamics simulations

Hybrid lead halide perovskites are a class of materials that have unique photophysical properties due to their anharmonic lattices and predominately ionic bonding. Recently, layered perovskites have been synthesized with large organic cations. These flexible structures have optical properties that can in principle be easily controlled by composition and thickness, enabling their use in a variety of optoelectronic applications. The interplay between organic cations and the inorganic framework significantly affects the material properties, resulting in flexible lattices with significant dynamic disorder and soft vibrational modes. In this work, we aim to elucidate the effects of anharmonicity and study the relaxation dynamics of the lattice due to photogenerated excitons by using advanced molecular dynamics simulations. This work may provide the foundation for future studies on novel electron-phonon interactions in these materials.