High-power laser-patterning graphene oxide: A new approach to making arbitrarily-shaped self-aligned electrodes

We demonstrate the fabrication of self-aligned laser-reduced graphene oxide patterns with a spatial resolution/laser spot size ratio of 1/10, lower than anything reported before using laser-reduction. Laser light modifies graphene oxide (GO) by removing the oxygen-containing groups turning GO into a more graphene-like nanomaterial. Our method is based on high laser power density used for the reduction of GO that results in ablation of the GO film. This enabled us to remove the laser spot illuminated area while inducing the selective graphene oxide reduction at the periphery of the laser spot achieving resistivity of 1.6.10(-5) Omega m, as low as values previously reported for other rGO. Therefore, we can exploit laser-induced reduction at high laser power density to pattern GO films with conductive dimensions that are a fraction of the laser spot size. This innovative method is scalable, inexpensive, and straightforward, allowing conductive circuits on arbitrary, flexible, and transparent substrates for applications in lightweight electronics and wearables. (C) 2019 Elsevier Ltd. All rights reserved.