Plasma-assisted reduction of graphene oxide at low temperature and atmospheric pressure for flexible conductor applications

Reduction of graphene oxide (GO) at low temperature and atmospheric pressure via plasma-assisted chemistry is demonstrated. Hydrogen gas is continuously dissociated in a microplasma to generate atomic hydrogen, which flows from the remote plasma to thin films of GO deposited on a substrate. Direct interaction with ions and other energetic species is avoided to mitigate ion-induced sputter removal or damage. The residual oxygen content and structure of the GO films after plasma treatment is systematically characterized at different temperatures and correlated to the conductivity of the films. For example, at 150 °C, we find that the plasma-reduced GO contains less than 12.5% oxygen and exhibits a sheet resistance of 4.77 × 10 ⁴ ω/sq, as compared with thermal reduction alone, which results in 22.9% oxygen and a sheet resistance of 2.14 × 10 ⁶ ω/sq. Overall, the effective removal of oxygen functional groups by atomic hydrogen enables large-scale applications of GO as flexible conductors to be realized.