Highly Efficient Spin‐Filtering Transport in Chiral Hybrid Copper Halides

Abstract

Chiral Pb(Sn)-I hybrid organic-inorganic perovskites exhibit outstanding chiral-induced spin selectivity (CISS) performance, but the nontoxic lead-free hybrid materials with high stability are still greatly desired for spin filtering in spintronic applications. We synthesize chiral hybrid copper halides (R/S-MBA)₂ CuX₄ (MBA=methylbenzylammonium; X=Cl, Br) with characteristic 0D CuX₄ tetrahedral structural motifs, combining the low toxicity of Cu²⁺ and air stability of halide ions (Cl^- and Br^- ). Despite similar structural and electronic features, (R/S-MBA)₂ CuBr₄ shows much smaller chiroptical activity than the chloride counterpart. Magnetically conductive atomic force microscopy measurements display a typical spin-polarized charge-transport property with high efficiency up to 90 % for both copper halides. Our work expands the CISS effect into eco-friendly and stable metal-organic halides, which is promising for applications in spintronics based on transition-metal hybrid systems.