Large tunneling magnetoresistance based on near-room-temperature 2D ferromagnetic semiconductor Cr₂Se₃

Motivated by the recent synthesis of two-dimensional ferromagnetic semiconductors (2DFMSs) Cr₂Se₃ films with a record Curie temperature (T_C, 230 K), we employ first-principles calculations to investigate the electronic structure of monolayer Cr₂Se₃, as well as the spin-transport properties of magnetic tunnel junctions (MTJs) composed of Cr₂Se₃ ferromagnetic layers with various electrodes and tunnel barriers. Our results reveal that the monolayer Cr₂Se₃ possesses a high T_C of 274 K, which is attributed to robust in-plane and out-of-plane exchange couplings. Moreover, devices with Au electrodes exhibit tunneling magnetoresistance (TMR) values exceeding 1.00 × 10⁴%, resulting from a half-metal-like transition in Cr₂Se₃, while the TMR in a device with graphene (Gr) electrodes reaches 2.00 × 10 ³ % upon modifying the tunnel barrier. Additionally, we investigate spin transport properties in asymmetric-electrode configurations and observe a distinct spin-filtering effect in the current-voltage characteristics of the Au-electrode devices. Overall, our findings elucidate the spin transport mechanisms and performance optimization strategies for Cr₂Se₃-based van der Waals (vdW) MTJs, paving the way for high-performance 2D spintronic devices.