Interfacial Chemical Vapor Deposition of Wrinkle-Free Bilayer Graphene on Dielectric Substrates

Abstract

Wrinkles invariably form during graphene growth and post-growth transfer, limiting graphene films' large-scale uniformity for electronic applications. We report a transfer-free synthesis route for highly-uniform bilayer graphene directly on dielectric substrates—SiO2, sapphire, and MgO—by interfacial carbon precipitation. Ultrathin Pd leaves having a thickness of 150 nm and grain size up to 100 µm are laminated onto the target dielectric substrate, followed by annealing and press rolling to form a uniform Pd-substrate interface. Rapid heating in a hydrocarbon atmosphere causes carbon diffusion through the Pd layer; upon cooling, precipitation of carbon results in graphene growth at the Pd-substrate interface. The interface-grown graphene remains on the substrate after removing the Pd layer by wet etching. It exhibits sub-nm surface roughness without wrinkles or folds. Over 94% of the interface-grown area is dominated by bilayer graphene with low twist angles. In addition, the interface-grown graphene is nearly strain-free. From Raman characterization, an average long-range scattering mobility of ∼1000 cm2 V-1 s-1 was estimated for as-grown bilayer graphene on sapphire (0001) at room temperature. This technique shows promise to achieve device scale, ultra-uniform graphene fabrication directly on dielectric substrates, with the potential to accelerate graphene applications in electronics, photonics, and sensing.

Kaihao Zhang

My research interests include metal additive manufacturing, cabron nanomaterials, and composite materials.