• Van De Goor, Tim W. J.
• Cerullo, Giulio
• Camargo, Franco V. A.
• Abolins, Haralds
• Shivanna, Ravichandran
• Friend, Richard, H.
• Senanayak, Satyaprasad P.
• Eyre, Lissa
• Bourelle, Sean A.
• Feldmann, Sascha
• Deschler, Felix
• Gillett, Alexander J.
• Winkler, Thomas
• Ghosh, Soumen
• Ashoka, Arjun

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 ∼1017 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.

Topics

• density
• perovskite
• photoluminescence
• layered
• spectroscopy