| Autor: |
Lan Y; Department of Physics, McGill University, Montreal, QC H3A 2T8, Canada., Dringoli BJ; Department of Physics, McGill University, Montreal, QC H3A 2T8, Canada., Valverde-Chávez DA; Department of Physics, McGill University, Montreal, QC H3A 2T8, Canada., Ponseca CS Jr; Division of Biomolecular and Organic Electronics, IFM, Linköpings Universitet, Linköping SE- 58183, Sweden., Sutton M; Department of Physics, McGill University, Montreal, QC H3A 2T8, Canada., He Y; Department of Chemistry, Northwestern University, Evanston, IL 60208, USA., Kanatzidis MG; Department of Chemistry, Northwestern University, Evanston, IL 60208, USA., Cooke DG; Department of Physics, McGill University, Montreal, QC H3A 2T8, Canada. |
| Abstrakt: |
Hybrid organic-inorganic halide perovskites have shown remarkable optoelectronic properties, exhibiting an impressive tolerance to defects believed to originate from correlated motion of charge carriers and the polar lattice forming large polarons. Few experimental techniques are capable of directly probing these correlations, requiring simultaneous sub-millielectron volt energy and femtosecond temporal resolution after absorption of a photon. Here, we use time-resolved multi-THz spectroscopy, sensitive to the internal excitations of the polaron, to temporally and energetically resolve the coherent coupling of charges to longitudinal optical phonons in single-crystal CH 3 NH 3 PbI 3 (MAPI). We observe room temperature intraband quantum beats arising from the coherent displacement of charge from the coupled phonon cloud. Our measurements provide strong evidence for the existence of polarons in MAPI at room temperature, suggesting that electron/hole-phonon coupling is a defining aspect of the hybrid metal-halide perovskites contributing to the protection from scattering and enhanced carrier lifetimes that define their usefulness in devices. |
