Gate-controlled spin injection polarity in 2D transistors with Schottky barrier.

In 2D semiconductors, the Schottky barrier formed at the metal–semiconductor interface plays a crucial role in controlling electron and spin injection. To explore the spin injection mechanism under gate control, we study MoS 2 coupled to ferromagnetic metals. We introduce a spin drift diffusion model which is applicable to the Schottky contact. In this system, the current passing through the Schottky barrier can be larger for the minority spin than for the majority spin due to the tunnel effect. We observe a polarity switching in spin injection with gate voltage variation when the conduction band bottom of the minority spin ferromagnetic metal is closely aligned with the Fermi level. Our results also suggest the spin injection efficiency can be tuned by gate control for half-metals. • Research explores spin injection from ferromagnetic metal into 2D semiconductors. • Spin current polarization is examined by drift diffusion simulations. • Gate voltage can alter current switch polarity under specific conditions. • High spin injection efficiency can be realized with gate voltage for half-metals. [ABSTRACT FROM AUTHOR]