Gate tunable spin-charge interconversion in a graphene/ReS${}_2$ heterostructure up to room temperature

Graphene is a material with great potential in the field of spintronics, combining good conductivity with low spin–orbit coupling (SOC), which allows for the transport of spin currents over long distances. However, this lack of SOC also limits the capacity for manipulating spin current. A key strategy to address this limitation is to induce SOC in graphene via proximity to other two-dimensional (2D) materials. Such proximity-induced SOC can enable spin–charge interconversion (SCI) in graphene, with potential applications in next-generation logic devices. Here, we place graphene in close proximity to the room-temperature ferroelectric candidate ReS${}_2$, inducing SCI for both in-plane and out-of-plane polarized spin current. We attribute the SCI for in-plane polarized current to either the Rashba–Edelstein effect (REE) or the unconventional spin Hall effect (SHE) at the graphene/ReS${}_2$ interface, and the SCI for out-of-plane polarized current to either the conventional SHE in the proximitised graphene, or the unconventional SHE in the bulk of the ReS${}_2$. SCI due to in-plane spin is characterised over a wide range of temperature, up to 300 K and a range of gate voltages.