Speaker
Nicola Colonna
(Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland)
Description
Lead-halide perovskite (LHP) semiconductors rival conventional semiconductors in multiple optoelectronic applications. The origin of such outstanding transport propeties are howerer not yet fully understood. We find signatures of large polaron formation in the electronic structure of the inorganic LHP CsPbBr$_3$ by means of angle-resolved photoelectron spectroscopy. The experimental valence band dispersion shows a hole effective mass 0.26$\pm$0.02 m$_e$, 50% heavier than the bare mass m$_0$=0.17 m$_e$ predicted by density functional theory. Calculations of electron-phonon coupling indicate that phonon dressing of the carriers mainly occurs via distortions of the Pb-Br bond with a Fröhlich coupling parameter $\alpha$=1.82. A good agreement with our experimental data is obtained within the Feynmann polaron model, validating a viable theorical method to predict the carrier effective mass of LHPs $ab\,initio$.
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Primary authors
Nicola Colonna
(Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland)
Michele Puppin
(Laboratoire de Spectroscopie Ultrarapide and Lausanne Centre for Ultrafast Science (LACUS), Ecole Polytechnique Federale de Lausanne, ISIC, Station 6, CH-1015 Lausanne, Switzerland)
Serhii Polishchuck
(Laboratoire de Spectroscopie Ultrarapide and Lausanne Centre for Ultrafast Science (LACUS), Ecole Polytechnique Federale de Lausanne, ISIC, Station 6, CH-1015 Lausanne, Switzerland)
Andrea Crepaldi
(Institute of Physics and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland)
Dmitry Dirin
(Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Z{\"u}rich, CH-8093 Z{\"u}rich, Switzerland}, and Laboratory for Thin Films and Photovoltaics, EMPA – Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 D{\"u}bendorf, Switzerland)
Olga Nazarenko
(Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Z{\"u}rich, CH-8093 Z{\"u}rich, Switzerland}, and Laboratory for Thin Films and Photovoltaics, EMPA – Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 D{\"u}bendorf, Switzerland)
Riccardo de Gennaro
(Theory and Simulations of Materials (THEOS), and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland)
Gianmarco Gatti
(Institute of Physics and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland)
Silvan Roth
(Institute of Physics and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland)
Thomas Roland Barillot
(Laboratoire de Spectroscopie Ultrarapide and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne, ISIC, Station 6, CH-1015 Lausanne, Switzerland)
Luca Poletto
(National Research Council of Italy - Institute of Photonics and Nanotechnologies (CNR-IFN), via Trasea 7, 35131 Padova, Italy)
Rui Patrick Xian
(Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany)
Laurenz Retting
(Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany)
Maximilian Walf
(Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany)
Ralph Ernstorfer
(Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany)
Maksym Kovalenko
(Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Z{\"u}rich, CH-8093 Z{\"u}rich, Switzerland, and Laboratory for Thin Films and Photovoltaics, EMPA – Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 D{\"u}bendorf, Switzerland)
Marzari Nicola
(Theory and Simulations of Materials (THEOS), and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland)
Grioni Marco
(Institute of Physics and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland)
Majed Chergui
(Laboratoire de Spectroscopie Ultrarapide and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne, ISIC, Station 6, CH-1015 Lausanne, Switzerland)
