Spin-Polarized Magneto-Optical Properties of Organic-Inorganic Perovskite Materials Doped with Lanthanide Ions

Lead halide perovskite materials have shown remarkable potential across various optoelectronic applications. Lanthanide ions such as Nd²⁺ and Eu³⁺, with ionic radii similar to that of Pb²⁺, can be easily integrated into the crystal lattice of perovskite materials, thereby influencing their electronic, optical, and magnetic properties. Doping lanthanide ions into these materials provides an innovative method for adjusting their optoelectronic properties by utilizing the interaction between excitons and localized spins, activated through light-matter interaction. Our research underscores the strong spin coupling between impurity dopants and light-generated photoelectrons, particularly at cryogenic temperatures, facilitated by exchange interactions. Experimental results from our research demonstrated that Nd²⁺- doped CH₃NH₃PbI₃ perovskites exhibit a Kondo-like exciton-spin interaction under cryogenic and photoexcitation conditions. This interaction is characterized by prolonged carrier lifetimes, as measured by time-resolved photoluminescence, compared to undoped CH₃NH₃PbI₃. Notably, this Kondo-like interaction can be suppressed by an external magnetic field, which aligns the spin angular momentum of Nd²⁺ ions and restores exciton recombination dynamics to levels similar to those observed in pure CH₃NH₃PbI₃. The choice of lanthanide ions is informed by their distinct quantum numbers, which can lead to significant energy level splitting and result in notable variations in the magneto-optical properties of lanthanide-doped perovskite materials. The developed techniques for manipulating spin-exciton interactions reveal the potential for creating advanced optoelectronic materials and exploring applications in the field of quantum science.