Gate voltage-controlled spin-rectifier diode based on Janus transition metal nitride MXene with spin gapless semiconductor

Abstract

With the continuous application of spintronics technology, spintronic devices have been expected to become a major direction in the development of next-generation electronic devices. However, for spin rectifier diodes, how to provide a large number of spin-polarized carriers is still a key technical issue. Conventional spin-polarization injection models use ferromagnetic (FM)/semiconductor structures, but because of the conductivity mismatch can limit the injection of their polarization. This makes the search for spin-gapless semiconductor which has the conductivity between metals and semiconductors an effective way to solve this problem. Recently, MXene, a new two-dimensional material with high spin polarization, has been expected to undergo modulation of the electronic structure through external field or proximity effects. Subsequently, we propose a Janus transition metal structure of the MXene which modulates the spin properties by breaking the symmetry of the transition metals. Moreover, we find the band structure of TiCrNO2 can be effectively modulated by an applied electric field, which transforms itself from a magnetic semiconductor to a spin-gapless semiconductor under an electric field strength of 1 V/Å. With this as a basis, we construct a tunable spin rectifier diode and study its spin rectification effect by the first-principle calculations combined with non-equilibrium Green's function. The results show that the rectification ratio of the spin rectification diode can be adjustable by varying the strength of the external electric field, and its rectification rate exceeds the highest value currently available for two-dimensional rectifier devices. Our results provide a reference value for the application of nitride MXene in spintronic devices.