Mahan excitons in room-temperature methylammonium lead bromide perovskites
-
Palmieri, Tania
Laboratory of Ultrafast Spectroscopy, Lausanne Centre for Ultrafast Science (LACUS), Institute of Chemistry and Chemical Engineering (ISIC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland -
-
Baldini, Edoardo
Laboratory of Ultrafast Spectroscopy, Lausanne Centre for Ultrafast Science (LACUS), Institute of Chemistry and Chemical Engineering (ISIC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland -
-
Steinhoff, Alexander
Semiconductor Theory Group, Institute for Theoretical Physics, University of Bremen, Otto-Hahn-Alle 1, P.O. Box 330440, Bremen, Germany
-
Akrap, Ana
Group of Light Fermion Spectroscopy, Department of Physics, Université de Fribourg, 3 Chemin du Musée, 1700 Fribourg, Switzerland
-
Kollár, Márton
Laboratory of Physics of Condensed Matter, Institute of Physics (IPHYS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
-
Horváth, Endre
Laboratory of Physics of Condensed Matter, Institute of Physics (IPHYS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
-
Forró, László
Laboratory of Physics of Condensed Matter, Institute of Physics (IPHYS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
-
Jahnke, Frank
Semiconductor Theory Group, Institute for Theoretical Physics, University of Bremen, Otto-Hahn-Alle 1, P.O. Box 330440, Bremen, Germany
-
Chergui, Majed
Laboratory of Ultrafast Spectroscopy, Lausanne Centre for Ultrafast Science (LACUS), Institute of Chemistry and Chemical Engineering (ISIC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
Show more…
Published in:
- Nature Communications. - 2020, vol. 11, no. 1, p. 850
English
In a seminal paper, Mahan predicted that excitonic bound states can still exist in a semiconductor at electron-hole densities above the insulator-to-metal Mott transition. However, no clear evidence for this exotic quasiparticle, dubbed Mahan exciton, exists to date at room temperature. In this work, we combine ultrafast broadband optical spectroscopy and advanced many-body calculations to reveal that organic-inorganic lead-bromide perovskites host Mahan excitons at room temperature. Persistence of the Wannier exciton peak and the enhancement of the above-bandgap absorption are observed at all achievable photoexcitation densities, well above the Mott density. This is supported by the solution of the semiconductor Bloch equations, which confirms that no sharp transition between the insulating and conductive phase occurs. Our results demonstrate the robustness of the bound states in a regime where exciton dissociation is otherwise expected, and offer promising perspectives in fundamental physics and in room-temperature applications involving high densities of charge carriers.
-
Faculty
- Faculté des sciences et de médecine
-
Department
- Département de Physique
-
Language
-
-
Classification
-
Physics
-
License
-
License undefined
-
Identifiers
-
-
Persistent URL
-
https://folia.unifr.ch/unifr/documents/308554
Statistics
Document views: 53
File downloads: