Enhancing the Hot-Phonon Bottleneck Effect in a Metal Halide Perovskite by Terahertz Phonon Excitation

We investigate the impact of phonon excitations on the photoexcited carrier dynamics in a lead-halide perovskite CH3NH3PbI3, which hosts unique low-energy phonons that can be directly excited by terahertz pulses. Our time-resolved photoluminescence measurements reveal that strong terahertz excitation prolongs the cooling time of hot carriers, providing direct evidence for the hot-phonon bottleneck effect. In contrast to the previous studies where phonons are treated as a passive heat bath, our results demonstrate that phonon excitation can significantly perturb the carrier relaxation dynamics in halide perovskites through the coupling between transverse- and longitudinal-optical phonons.

Automated summary

The impact of phonon excitations on the photoexcited carrier dynamics in lead-halide perovskite CH3NH3PbI3 was investigated, showing that strong terahertz excitation can prolong the cooling time of hot carriers. The results demonstrate that phonon excitation significantly perturbs the carrier relaxation dynamics in halide perovskites through the coupling between transverse- and longitudinal-optical phonons.