Photocarrier-induced persistent structural polarization in soft-lattice lead halide perovskites.
Nat Nanotechnol
; 18(4): 357-364, 2023 Apr.
Article
em En
| MEDLINE
| ID: mdl-36702955
ABSTRACT
The success of the lead halide perovskites in diverse optoelectronics has motivated considerable interest in their fundamental photocarrier dynamics. Here we report the discovery of photocarrier-induced persistent structural polarization and local ferroelectricity in lead halide perovskites. Photoconductance studies of thin-film single-crystal CsPbBr3 at 10 K reveal long-lasting persistent photoconductance with an ultralong photocarrier lifetime beyond 106 s. X-ray diffraction studies reveal that photocarrier-induced structural polarization is present up to a critical freezing temperature. Photocapacitance studies at cryogenic temperatures further demonstrate a systematic local phase transition from linear dielectric to paraelectric and relaxor ferroelectric under increasing illumination. Our theoretical investigations highlight the critical role of photocarrier-phonon coupling and large polaron formation in driving the local relaxor ferroelectric phase transition. Our findings show that this photocarrier-induced persistent structural polarization enables the formation of ferroelectric nanodomains at low temperature, which suppress carrier recombination and offer the possibility of exploring intriguing carrier-phonon interplay and the rich polaron photophysics.
Texto completo:
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Base de dados:
MEDLINE
Idioma:
En
Revista:
Nat Nanotechnol
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Estados Unidos