%0 Journal Article
%T Direct evidence of weakly dispersed and strongly anharmonic optical phonons in hybrid perovskites
%+ Institut des Sciences Chimiques de Rennes (ISCR)
%+ Institut des Fonctions Optiques pour les Technologies de l'informatiON (FOTON)
%+ Institut Laue-Langevin (ILL)
%+ Magnétisme et Diffusion Neutronique (MDN )
%+ Laboratoire Charles Coulomb (L2C)
%+ Laboratoire Léon Brillouin (LLB - UMR 12)
%+ LLB - Nouvelles frontières dans les matériaux quantiques (NFMQ)
%A da Cunha Ferreira, Afonso
%A Paofai, Serge
%A Létoublon, Antoine
%A Ollivier, Jacques
%A Raymond, Stéphane
%A Hehlen, Bernard
%A Bourges, Philippe
%A Rufflé, Benoit
%A Cordier, Stéphane
%A Katan, Claudine
%A Even, Jacky
%< avec comité de lecture
%@ 2399-3650
%J Communications Physics
%I Nature Research
%V 3
%N 48
%8 2020-03-12
%D 2020
%R 10.1038/s42005-020-0313-7
%Z Physics [physics]
%Z Chemical SciencesJournal articles
%X Hybrid organolead perovskites (HOP) have started to establish themselves in the field of photovoltaics, mainly due to their great optoelectronic properties and steadily improving solar cell efficiency. Study of the lattice dynamics is key in understanding the electron-phonon interactions at play, responsible for such properties. Here, we investigate, via neutron and Raman spectroscopies, the optical phonon spectrum of four different HOP single crystals: MAPbBr3, FAPbBr3, MAPbI3, and α-FAPbI3. Low temperature spectra reveal weakly dispersive optical phonons, at energies as low as 2-5 meV, which seem to be the origin of the limit of the charge carriers mobilities in these materials. The temperature dependence of our neutron spectra shows as well a significant anharmonic behaviour, resulting in optical phonon overdamping at temperatures as low as 80 K, questionning the validity of the quasi-particle picture for the low energy optical modes at room temperature where the solar cells operate.
%G English
%2 https://hal.science/hal-02507269/document
%2 https://hal.science/hal-02507269/file/s42005-020-0313-7.pdf
%L hal-02507269
%U https://hal.science/hal-02507269
%~ CEA
%~ INSTITUT-TELECOM
%~ UNIV-RENNES1
%~ UGA
%~ CNRS
%~ INSA-RENNES
%~ ENSC-RENNES
%~ FOTON
%~ FOTON-INSA
%~ OPENAIRE
%~ L2C
%~ ISCR
%~ FOTON_OHM
%~ ISCR-CTI
%~ ISCR-CSM
%~ STATS-UR1
%~ DSV
%~ UR1-SPM
%~ INC-CNRS
%~ IRAMIS-LLB
%~ CEA-UPSAY
%~ UR1-UFR-SPM
%~ UR1-HAL
%~ UR1-MATH-STIC
%~ UR1-SDLM
%~ UNIV-PARIS-SACLAY
%~ MIPS
%~ UNIV-MONTPELLIER
%~ CEA-DRF
%~ TEST-UR-CSS
%~ UNIV-RENNES
%~ INSA-GROUPE
%~ IRIG
%~ CEA-GRE
%~ TEST-HALCNRS
%~ UNIVERSITE-PARIS-SACLAY
%~ UGA-EPE
%~ UR1-MATH-NUM
%~ UR1-MMS
%~ GS-ENGINEERING
%~ IRAMIS
%~ GS-CHIMIE
%~ GS-PHYSIQUE
%~ GS-LIFE-SCIENCES-HEALTH
%~ UM-2015-2021
%~ TEST2-HALCNRS