A Local Study of the Transport Mechanisms in MoS₂ Layers for Magnetic Tunnel Junctions

MoS₂-based vertical spintronic devices have attracted an increasing interest thanks to theoretical predictions of large magnetoresistance signals. However, experimental performances are still far from expectations. Here, we carry out the local electrical characterization of thin MoS₂ flakes in a Co/Al₂O₃/MoS₂ structure through conductive tip AFM measurements. We show that thin MoS₂ presents a metallic behavior with a strong lateral transport contribution that hinders the direct tunnelling through thin layers. Indeed, no resistance dependence is observed with the flake thickness. These findings reveal a spin depolarization source in the MoS₂-based spin valves, thus pointing to possible solutions to improve their spintronic properties.