Ultrafast spin relaxation mechanisms in layered hybrid perovskites

Ruddlesden-Popper two-dimensional layered perovskites are hybrid organic-inorganic materials that alternate a number n of perovskite layers with a single organic spacer layer [1] . Important parameters such as the dielectric environment, crystal symmetry and spin-orbit coupling can be varied based on composition, making these materials promising for spintronic applications. In this work we combine ultrafast transient absorption and ultrafast Faraday rotation to study the spin relaxation mechanisms in a lead iodide bilayer ( n = 2) perovskite, namely (BA) 2 (FA) 1 Pb 2 I 7 (BA, Butylammonium; FA, Formamidinium). We observe that different absorption bands present different spin relaxation mechanisms.