SKM 2023 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 17: THz and MIR physics in semiconductors
HL 17.9: Vortrag
Dienstag, 28. März 2023, 12:00–12:15, JAN 0027
Coherent phonon dynamics in quasi-2D perovskites probed by THz-induced Kerr effect — •Joanna M. Urban1, Marie Cherasse1,2, Maximilian Frenzel1, Michael Spencer1, Gaelle Trippe-Allard3, Emmanuelle Deleporte3, Luca Perfetti2, Martin Wolf1, and Sebastian F. Maehrlein1 — 1FHI of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany — 2LSI, Palaiseau, France — 3Université Paris-Saclay, LuMIn, Gif-sur-Yvette, France
2D hybrid organic-inorganic perovskites (HOIP) are self-assembled multiple quantum well structures, formed by metal halide octahedral layers alternating with large organic spacer cations. They combine the intriguing properties of the 3D HOIP polar, anharmonic lattice with optoelectronic properties arising due to low dimensionality. We study a family of 2D HOIPs in the Ruddlesden-Popper phase (PEA)2(MA)n−1PbnI3n+1 (n=1,2,3). Using intense, close to single-cycle THz fields we excite coherent optical phonons and probe the lattice dynamics via THz-induced Kerr effect (TKE). Strikingly, we observe long-lived coherent phonon oscillations at room temperature. Comparison with static Raman spectroscopy results as well as the measured fluence and temperature dependence confirm that the observed features in the 0.5-3 THz range correspond to Raman-active modes of the inorganic sublattice, excited via a nonlinear driving process. The nontrivial azimuthal angle dependence of the TKE signal can be explained considering the crystal structure and the symmetry of the Raman modes using the χ(3) nonlinear susceptibility tensor formalism.