Direct Laser Writing of Graphene Nanoribbon Thin Films for Supercapacitor Electrodes

Recent developments of low-power electronic devices have triggered interests towards small-scale energy storage. One promising approach is to fabricate micro-supercapaciors (MSCs). In this work, we demonstrate a facile fabrication of MSCs by laser reduction and patterning of graphene oxide nanoribbon (GONR) thin films coated on poly(ethylene terephthalate) substrate through LightScribe technique. We fabricated the in-plane geometry electrodes consisting of reduced GONRs (i.e., graphene nanoribbons, GNRs) with the lateral spatial resolution of approximately 20 µm in addition to the stacked geometry electrodes for comparison. The fabricated in-plane-GNR electrode device showed superior electrochemical properties compared with the stacked-GNR electrode ones. Our impedance measurements supported that this is due to high lateral ion diffusivity along the basal plane of GNRs. In addition, GNR-based in-plane-electrode device also showed a higher capacitance than the graphene-based one, which is due to the more efficient edge effects of GNRs