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

We investigate the impact of phonon excitations on photoexcited carrier dynamics in a lead-halide perovskite ${\mathrm{CH}}_{3}{\mathrm{NH}}_{3}{\mathrm{PbI}}_{3}$, which hosts unique low-energy phonons that can be directly excited by terahertz pulses. Our time-resolved photoluminescence measurements reveal strong excitation prolongs cooling time hot carriers, providing direct evidence for hot-phonon bottleneck effect. In contrast to previous studies where are treated as passive heat bath, our results demonstrate significantly perturb relaxation halide perovskites through coupling between transverse- and longitudinal-optical phonons.