Coherent Spin Dynamics of Electrons in Two-Dimensional (PEA)₂PbI₄ Perovskites

The versatile potential of lead halide perovskites and two-dimensional materials is merged in the Ruddlesden–Popper perovskites having outstanding optical properties. Here, the coherent spin dynamics in Ruddlesden–Popper (PEA)₂PbI₄ perovskites is investigated by picosecond pump–probe Kerr rotation in an external magnetic field. The Larmor spin precession of resident electrons with a spin dephasing time of 190 ps is identified. The longitudinal spin relaxation time in weak magnetic fields measured by the spin inertia method is as long as 25 μs. A significant anisotropy of the electron g-factor with the in-plane value of +2.45 and out-of-plane value of +2.05 is found. The exciton out-of-plane g-factor of +1.6 is measured by magneto-reflectivity. This work contributes to the understanding of the spin-dependent properties of two-dimensional perovskites and their spin dynamics.