Functionalized Graphene for High-Performance Two-Dimensional Spintronics Devices

Using first-principles calculations, we explore the possibility of functionalized graphene as a high-performance two-dimensional spintronics device. Graphene functionalized with 0 on one side and H on the other side in the chair conformation is found to be a ferromagnetic metal with a spin-filter efficiency up to 54% at finite bias. The ground state of graphene semifunctionalized with Fin the chair conformation is an anttferromagnetic semiconductor, and we construct a spin-valve device from it by introducing a magnetic field to stabilize its metallic ferromagnetic state. The resulting room temperature magnetoresistance Is up to 2200%, which is 1 order of magnitude larger than the available experimental values.