Neutron scattering in metal halide perovskites

Halide perovskites (HPs) have attracted attention for their excellent performance in optoelectronic applications such as solar cells, light-emitting devices (LEDs), and photodetectors. This is mainly due to their strong electron-phonon coupling (EPC). Low-dimensional HPs typically change the crystal lattice, improving carrier diffusion length properties, reducing electron-hole recombination, and increasing EPC. Furthermore, strong EPC in these materials may lead to the creation of self-trapped excitons (STEs), which emit broad luminescence across multiple wavelengths. The low-dimensional perovskites Cs₂SnBr₆ and CsPb₂Br₅ are particularly promising for LEDs due to their high photoluminescence quantum yield (PLQY) and broad emission spectrum. However, the phonon scattering mechanisms in these materials are not yet fully understood, and conventional spectroscopic techniques offer limited insights. Inelastic Neutron Scattering (INS) provides a powerful method to probe phonon dispersion and EPC mechanisms, offering critical insights into optimizing these materials in energy harvesting and optoelectronic applications. This research promises to bridge significant knowledge gaps and drive advancements in the design of next-generation perovskite-based state-of-the-art technologies.