Argon ion beam–induced controlled carbonization of polyimide film: An in-situ XPS study of surface chemistry

This work presented a sustainable, solvent-free route to carbonize polyimide (PI) surfaces using Ar⁺ ion beam irradiation at 1000 and 2000 eV with 0–90 sec exposures (10-sec steps). In-situ XPS tracked elemental and chemical-state evolution during irradiation, enabling a single-platform workflow for ion-beam–induced carbonization and chemical-state verification within the same vacuum cycle. Increasing dose raised surface %C and suppressed C–O/C=O/O–C=O, with C 1s/O 1s deconvolutions evidencing deoxygenation and sp²-hybridized carbon growth within the ion-beam–irradiated regions. The 2000 eV condition achieved faster, more complete conversion than 1000 eV within 90 sec. The method delivered a low-thermal-budget, energy- and fluence-resolved approach without hazardous reagents or long thermal cycles and identified actionable processing windows while minimizing sputter mixing. Practically, it repurposed a standard XPS/ion-gun platform to produce scalable, carbon-rich PI surfaces with immediate, quantitative verification—with conclusions limited to XPS-based chemical analysis, providing readers with a concise recipe for flexible electronics, protective coatings, and related applications.