Interfacial Copper Oxidation Under an Applied Alternating Electric Field and a Water-Soluble Caramel Support Enable...

Graphene is a promising platform for next-generation electronics, yet conventional transfer from catalytic metals often introduces cracks, wrinkles, polymer residues, and unintended doping that compromise device performance. Here, we report a synergistic transfer strategy combining interfacial Cu oxidation under an applied 50 Hz AC electric field with a water-soluble caramel support. Under otherwise identical aqueous-treatment conditions, the AC-field-treated graphene/Cu exhibits faster oxidation propagation and lower spatial heterogeneity than the water-only control, producing a Cu₂O-rich interfacial state favorable for subsequent graphene delamination. The caramel support, prepared from sucrose and corn syrup, provides tunable thermomechanical compliance, conformal contact with diverse target substrates, weak interaction with graphene, and facile aqueous removal. Using this approach, graphene was successfully transferred at the 4-inch scale onto SiO₂/Si and other substrates, with a root-mean-square surface roughness of 0.73 nm. Compared with PMMA-transferred controls, the resulting graphene exhibited reduced support-derived contamination, fewer transfer-induced structural perturbations, weaker p-type doping, and improved carrier transport. This work provides a scalable route for clean, low-damage, large-area graphene transfer and device integration.