Sekiguchi Fumiya, Hirori Hideki, Yumoto Go, Shimazaki Ai, Nakamura Tomoya, Wakamiya Atsushi, Kanemitsu Yoshihiko
Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
Phys Rev Lett. 2021 Feb 19;126(7):077401. doi: 10.1103/PhysRevLett.126.077401.
We investigate the impact of phonon excitations on the photoexcited carrier dynamics in a lead-halide perovskite CH_{3}NH_{3}PbI_{3}, 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.
我们研究了声子激发对卤化铅钙钛矿CH₃NH₃PbI₃中光激发载流子动力学的影响，该材料具有独特的低能声子，可被太赫兹脉冲直接激发。我们的时间分辨光致发光测量结果表明，强太赫兹激发延长了热载流子的冷却时间，为热声子瓶颈效应提供了直接证据。与之前将声子视为被动热库的研究不同，我们的结果表明，声子激发可通过横向和纵向光学声子之间的耦合，显著扰动卤化物钙钛矿中的载流子弛豫动力学。
