Increasing the Magnetic Transition Dipole Moment of Chiral Perovskite Through Eu3+ Doping

Chiral hybrid organic-inorganic perovskites (HOIPs) are widely investigated due to their superior chiroptical and chiral spintronic properties. Research on the enhancement of chiroptical performance is highly important for the real application of chiral HOIPs. This work employed a rare earth doping strategy to increase the magnetic transition dipole moment of chiral 2D HOIPs R-/S-NPB (NPB = 1-(1-naphthyl) ethylammonium lead bromide). Doping with Eu³⁺ does not change the original layered NPB microstructure, and R-/S-NPB-Eu exhibited the magnetic dipole-allowed transition luminescence of Eu³⁺ at 594 nm (⁵D₀→⁷F₁). Circular polarized luminescence (CPL) spectra combined with theoretical calculations and transient photoluminescence measurements indicated that the introduction of Eu³⁺ can enhance the magnetic transition dipole moment of R-/S-NPB, thus resulting in an unprecedented g_lum of 0.05. To the best of our knowledge, this is the highest value for chiral perovskite films. This work combines the unique and superior optoelectronic properties of rare-earth ions with chiral perovskite and develops an efficient strategy to increase its anisotropy factor, which can accelerate the development of chiral optoelectronics and spintronics towards real application.