Vertical field effect tunneling transistor based on graphene-ultrathin Si nanomembrane heterostructures

Graphene-based heterostructured vertical transistors have attracted a great deal of research interest. Herein we propose a Si-based technology platform for creating graphene/ultrathin semiconductor/ metal (GSM) junctions, which can be applied to large-scale and low-power electronics compatible with a variety of substrates.We fabricated graphene/Si nanomembrane (NM)/metal vertical heterostructures by using a dry transfer technique to transfer Si NMs onto chemical vapor depositiongrown graphene layers. The resulting van der Waals interfaces between graphene and p-Si NMs exhibited nearly ideal Schottky barrier behavior. Due to the low density of states of graphene, the graphene/Si NM Schottky barrier height can be modulated by modulating the band profile in the channel region, yielding well-defined current modulation.We obtained a maximum current on/off ratio (I_on/I_off) of up to ~10³, with a current density of 10² A cm^-2.We also observed significant dependence of Schottky barrier height Δ_φb on the thickness of the Si NMs.We confirmed that the transport in these devices is dominated by the effects of the graphene/Si NM Schottky barrier.