Direct and residue-free patterning of sub-5 µm CVD monolayer graphene with highly enhanced conductivity and pattern fidelity

Conventional photolithography-based patterning of monolayer graphene inevitably causes delamination and contamination when fabricating sub-5 μm patterns, rendering electrical characterization impossible. Here, we develop a one-step free patterning of graphene (OFP-G) method, which selectively converts C = C/C-C bonds into C-O bonds, enabling robust micro-sized pattern fabrication without delamination. OFP-G achieves intact 5 μm and 20 μm-wide patterns with resistances of 11.5 ± 2.8 Ω and 9.4 ± 0.4 Ω, respectively, overcoming the inherent limitations of photolithographic approaches that induce graphene delamination and contamination. Molecular dynamics simulations reveal that C-O bond conversion significantly reduces interfacial strain, while Raman and XPS analyses confirm that the patterned regions maintain structural integrity without etching-induced defects. By eliminating photoresist contamination and damage, this approach provides a scalable and reliable alternative for high-resolution graphene micro-sized pattern fabrication.