Md Azimul Haque, Pius M Theiler, Ian A Leahy, Steven P Harvey, Jeiwan Tan, Matthew P Hautzinger, Margherita Taddei, Aeron McConnell, Andrew Grieder, Andrew H Comstock, Yifan Dong, Kirstin Alberi, Yuan Ping, Peter C Sercel, Joseph M Luther, Dali Sun, Matthew C Beard
The combination of semiconducting properties and synthetically tunable chirality in chiral metal halide semiconductors (CMHSs) offers a compelling platform for room temperature control of electronic spin properties, leveraging effects such as chirality-induced spin selectivity (CISS). We report CISS-induced magnetoresistance (CISS-MR) exceeding 100% for spin valves operating at room temperature. The high CISS-MR is attributed to an interfacial tunneling barrier, modulated by chirality and spin, producing current dissymmetry factors (gc) that surpass the limit imposed by the Julliere model, which is governed by the intrinsic spin polarization of the adjacent ferromagnetic (FM) contact. The CISS-MR exhibits a dependence on the CMHS composition, revealing structure-property relationships between CISS and structural chirality. The observed exceptionally large tunneling MR response differs from a subtle anisotropic MR arising from the proximity effect at the FM/CMHS interface in the absence of a tunneling barrier. Our study provides insights into charge-to-spin interconversion in chiral semiconductors, offering design principles to control and enhance the CISS response for functional platforms.