How Exciton Interactions Control Spin-Depolarization in Layered Hybrid Perovskites.
Nano Lett
; 20(8): 5678-5685, 2020 Aug 12.
Article
em En
| MEDLINE
| ID: mdl-32574069
ABSTRACT
Using circularly polarized broadband transient absorption, time-resolved circular photoluminescence, and transient Faraday rotation spectroscopy, we report that spin-dependent interactions have a significant impact on exciton energies and spin depolarization times in layered Ruddlesden-Popper hybrid metal-halide perovskites. In BA2FAPb2I7, we report that room-temperature spin lifetimes are largest (3.2 ps) at a carrier density of â¼1017 cm-3 with increasing depolarization rates at higher exciton densities. This indicates that many-body interactions reduce spin-lifetimes and outcompete the effect of D'yakonov-Perel precessional relaxation that has been previously reported at lower carrier densities. We further observe a dynamic circular dichroism that arises from a photoinduced polarization in the exciton distribution between total angular momentum states. Our findings provide fundamental and application relevant insights into the spin-dependent exciton-exciton interactions in layered hybrid perovskites.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Nano Lett
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Reino Unido