title: Direct Experimental Evidence for Photoinduced Strong-Coupling Polarons in Organolead Halide Perovskite Nanoparticles.
abstract: Echoing the roaring success of their bulk counterparts, nano-objects built from organolead halide perovskites (OLHP) present bright prospects for surpassing the performances of their conventional organic and inorganic analogues in photodriven technologies. Unraveling the photoinduced charge dynamics is essential for optimizing the optoelectronic functionalities. However, mapping the carrier-lattice interactions remains challenging, owing to their manifestations on multiple length scales and time scales. By correlating ultrafast time-resolved optical and X-ray absorption measurements, this work reveals the photoinduced formation of strong-coupling polarons in CH3NH3PbBr3nanoparticles. Such polarons originate from the self-trapping of electrons in the Coulombic field caused by the displaced inorganic nuclei and the oriented organic cations. The transient structural change detected at the Pb L3X-ray absorption edge is well-captured by a distortion with average bond elongation in the [PbBr6]2-motif. General implications for designing novel OLHP nanomaterials targeting the active utilization of these quasi-particles are outlined.
authors: Department of Chemical Physics and Nanolund, Lund University , Box 124, 22100 Lund, Sweden.|Gas Processing Center, College of Engineering, Qatar University , PO Box 2713, Doha, Qatar.
authors: Kaibo
authors: K
authors: Zheng
authors: Department of Chemical Physics and Nanolund, Lund University , Box 124, 22100 Lund, Sweden.|Department of Chemistry, Qena Faculty of Science, South Valley University , Qena 83523, Egypt.
authors: Mohamed
authors: M
authors: Abdellah
authors: Department of Chemical Physics and Nanolund, Lund University , Box 124, 22100 Lund, Sweden.|Gas Processing Center, College of Engineering, Qatar University , PO Box 2713, Doha, Qatar.
authors: Qiushi
authors: Q
authors: Zhu
authors: X-ray Science Division, Advanced Photon Source and Materials Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors: Qingyu
authors: Q
authors: Kong
authors: X-ray Science Division, Advanced Photon Source and Materials Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors: Guy
authors: G
authors: Jennings
authors: X-ray Science Division, Advanced Photon Source and Materials Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors: Charles A
authors: CA
authors: Kurtz
authors: Department of Solid State Physics and Nanolund, Lund University , Box 118, 22100 Lund, Sweden.
authors: Maria E
authors: ME
authors: Messing
authors: MAX IV Laboratory, Lund University , Box 118, 22100 Lund, Sweden.
authors: Yuran
authors: Y
authors: Niu
authors: X-ray Science Division, Advanced Photon Source and Materials Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors: David J
authors: DJ
authors: Gosztola
authors: Gas Processing Center, College of Engineering, Qatar University , PO Box 2713, Doha, Qatar.
authors: Mohammed J
authors: MJ
authors: Al-Marri
authors: X-ray Science Division, Advanced Photon Source and Materials Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors: Xiaoyi
authors: X
authors: Zhang
authors: Department of Chemical Physics and Nanolund, Lund University , Box 124, 22100 Lund, Sweden.
authors: Tönu
authors: T
authors: Pullerits
authors: Center for Ultrafast Imaging, University of Hamburg , 22761 Hamburg, Germany.
authors: Sophie E
authors: SE
authors: Canton