A brief review of hot-carrier dynamics in metal halide perovskites: mechanistic insights from time-resolved spectroscopy

Abstract

Owing to their slow hot-carrier energy relaxation, metal halide perovskites have emerged as promising candidates for next-generation photovoltaics. This prolonged hot-carrier cooling allows excess energy to be harvested before dissipation as heat, thereby potentially enabling solar cells to exceed the Shockley-Queisser limit. Therefore, elucidating the mechanisms governing hot-carrier cooling is crucial for device optimization. Timeresolved spectroscopy enables observation of these ultrafast processes with high temporal resolution, revealing that intrinsic material properties, including A- and B-site compositions, fundamentally modulate lattice vibrations and electron-phonon coupling strength. Furthermore, structural dimensionality introduces quantum confinement effects that modify the phonon density of states and carrier interactions, while energy-recycling processes, such as phonon reabsorption and Auger-induced carrier reheating, aid in prolonging hot-carrier lifetimes. These mechanistic insights provide a clear understanding of hot-carrier dynamics, which is essential for developing high-efficiency hot-carrier solar cells and advanced optoelectronic devices.