Spinterfaces Manipulate Large Magnetic Field Effects in 3D and Quasi‐2D Organic–Inorganic Hybrid Perovskites

Spinterfaces are due to the orbital hybridization at an interface of a ferromagnet and a nonmagnetic semiconductor. Interfacial densities of states (i‐DOS) are spin‐dependent, which may offer the spin‐filter effect for enhancing spin‐polarized charge injection efficiency and magnetic field effects (MFEs). In the work, a prototypical perovskite spin valve (PeSV) comprising Ni/MAPbI3−xClx/Ni (MA = CH3NH3) is fabricated, showing a clear magnetic switching behavior in the ambient condition. It is further explored by studying the magnetophotocurrent (MPC) at the short‐circuit current density condition (magneto‐Jsc). Anomalously large magneto‐Jsc can be detected by comparing to devices with nonmagnetic Au electrodes. The effect can be more pronounced for the quasi‐2D perovskite such as (PEA)2(MA)3Pb4I13 (PEA = C6H5(CH2)2NH3). At low fields, the hyperfine field induced spin‐mixing shows remarkable magneto‐Jsc signals for it. In addition, the circularly and linearly polarized laser beam can effectively manipulate the magnitude of magneto‐Jsc for both MAPbI3−xClx and (PEA)2(MA)3Pb4I13. It is postulated that the formation of the spinterfaces may play a dominant role for the large and tunable magneto‐Jsc effect. These studies may pave the way for future experimental and theoretical studies in the field.