Acoustic-optical phonon up-conversion and hot-phonon bottleneck in lead-halide perovskites

Slow cooling of hot charge carriers in lead halide perovskite could be used in photovoltaics devices. Here, Yang et al. study hot carrier dynamics by transient absorption spectroscopy. They relate the phonon bottleneck to the up-conversion of low-energy phonons, facilitated by the presence of organic cations.