[25p-E206-1~9] 12.5 Organic solar cells

[25p-E206-4] Anharmonic organic cation vibrations in hybrid lead halide perovskite

〇Kunie Ishioka¹, Terumasa Tadano¹, Masatoshi Yanagida¹, Yasuhiro Shirai¹, Kenjiro Miyano¹ (1.NIMS)

Keywords:phonon, time-resolved spectroscopy, semiconductor

Lattice dynamics of an organic-inorganic hybrid lead halide perovskite is studied by means of time-resolved optical Kerr measurements. Coherent vibrations due to the libration and twisting of the organic cations are observed, in addition to the angular bending of the inorganic lattice. These vibrations are heavily damped and exhibit blue-shifts with increasing excitation density. Ab initio calculations confirm that the blue-shifts are manifests of the strong anharmonicity of the vibrational potentials.