Marc Hvid Overgaard: Graphene Oxide: A Candidate for Screen Printing of Flexible Electrode Circuits

posted 5 Jul 2017, 07:19 by Peter Boggild
University of Copenhagen, Department of Chemistry

Graphene inks are promising for roll-to-roll printing of flexible electronics. Currently, the most widely adapted strategy for formulating graphene inks is via liquid phase assisted exfoliation of graphite, but these inks requires electrically insulating binders/stabilizers to avoid flake re-aggregation. Thermal or photonic annealing is therefore needed in order to decompose the binders after printing in order to regain conductivity. Unfortunately this restricts the use of heat-sensitive plastic substrates.

In this presentation, we demonstrate a mildly oxidized graphene oxide (GO) hydrogel ink. The ink is water-based and binder-free and can be used for screen-printing applications of electrode circuitries [1]. Chemical reduction with trifluoro acetic acid and hydroiodic acid is used to efficiently reduce the printed GO films into reduced graphene oxide (rGO) films. This strategy allow us to circumvent traditional high-temperature annealing, while simultaneously yielding conductive films with 327 Ohm/sq at 37% transmittance. We also assess the tolerance to flexing, and find that the conductivity of the films is almost completely unaffected by film flexing.  

[1] M. H. Overgaard, M. Kühnel, R. Hvidsten, S. V. Petersen, T. Vosch, K. Nørgaard, B. W. Laursen, Adv. Mater. Technol. 2017

Marc Hvid Overgaard is currently a Ph.D. under Bo Wegge Laursen and Kasper Nørgaard in the Nano-Chemistry group at the University of Copenhagen. He received his B.Sc. and M.Sc. in nanoscience at the University of Copenhagen. His research interests are the chemical synthesis of graphene and graphene nano-composites and applications of graphene.