Liquid-Processed 2D Aromatic Amorphous Carbon: Defect Engineering and Universal Transport Scaling

Liquid-processed 2D aromatic amorphous carbons are emerging as a new materials platform in which distorted sp² networks combine scalability with unconventional electronic transport. Here, we report a deterministic pathway to produce graphene-derived amorphous 2D carbon thin films by combining the water processability of graphene oxide with rapid thermal quenching. During heating, the stepwise removal of oxygen groups generates vacancies and topological defects; rapid traversal of this regime prevents structural recovery and yields a kinetically trapped quasi-amorphous phase, termed quenched reduced graphene oxide (qRGO). XPS and UPS confirm that qRGO maintains predominantly sp² bonding, indicating a distorted aromatic network rather than a transition to sp³-rich amorphous carbon. Correlative structural and spectroscopic analyses reveal suppressed long-range order and boundary-like defect character in qRGO, contrasting with the vacancy-type defects of nanocrystalline reduced graphene oxide (RGO). Transport measurements show that RGO retains partial coherence and weak localization, whereas qRGO evolves into a strongly disordered regime governed by variable-range hopping. Despite these differences, both systems collapse onto a universal power-law scaling of resistivity. These results demonstrate that thermal-kinetic control of oxygen-driven defect formation provides a scalable route to functional 2D amorphous carbon films.