Ultra-high Mobility Semiconducting Graphene on Silicon Carbide

Graphene was recognized two decades ago as a potential next generation electronics material due to its 2D nature and extremely high mobility. However, the lack of a bandgap limited efforts to produce usable devices and attempts to induce a band gap failed to produce usable material. Here we present semiconducting epigraphene (SEG) grown by thermal evaporation on single crystal SiC substrates. SEG is the first graphene layer formed on the SiC Si face during the growth process and is partially bonded to the substrate. Here we show the SEG has a bandgap of 0.6eV and room temperature mobilities exceeding 5000 cm²/Vs, 20 times greater than other 2D semiconductors. Standard epigraphene growth, relying on controlled silicon sublimation, had previously been used to produce SEG, but with low mobilities due to disorder. In contrast, the SEG here is produced by a quasi-equilibrium process involving two face to face SiC chips. A balance between Si vapor confinement and SiC flow limits graphene growth to just SEG while creating macroscopic atomically flat terraces. The resulting material is highly ordered, chemically, mechanically, and thermally stable, patternable with standard lithography techniques, and can be seamlessly interconnected with epigraphene. Together, these properties make SEG a promising platform for future electronics.