[12a-B415-1~8] 3.6 Ultrashort-pulse and high-intensity lasers

[12a-B415-3] Phonon Anharmonicity in Hybrid Lead Halide Perovskite

〇Kunie Ishioka¹, Masatoshi Yanagida¹, Yasuhiro Shirai¹, Kenjiro Miyano¹ (1.NIMS)

Keywords:coherent phonon, lead halide perovskite

We have investigated ultrafast vibrational dynamics of hybrid lead halide perovskite CH₃NH₃PbI₃. Transient transmissivity exhibited periodic modulations due to coherent angular bending of the PbI₆ sublattice at 0.5 THz and the libration and torsion of the CH₃NH₃⁺ cation at 4 and 8 THz. The frequencies of the PbI₆ angular bending and the CH₃NH₃⁺ cation torsion exhibited clear phonon downchirps, demonstrating in the real time the strong anharmonicities of their vibrational potentials that were predicted by previous theoretical studies.