Facile Synthesis of Mildly Oxidized Graphite Inks for Screen‐Printing of Highly Conductive Electrodes

• Published in: Advanced engineering materials Vol. 21; no. 5
• Main Authors: Overgaard, Marc H., Sahlgren, Nicklas M., Hvidsten, Rasmus, Kühnel, Martin, Dalby, Kim N., Vosch, Tom, Laursen, Bo W., Nørgaard, Kasper
• Format: Journal Article
• Language: English
• Published: 01.05.2019
• Subjects: graphene inks; graphene oxide; printed electronics; screen‐printing
• ISSN: 1438-1656; 1527-2648
• DOI: 10.1002/adem.201801304

Graphene‐derived materials are attractive components in conductive inks for printed and flexible electronics. Here, the authors report a facile and scalable synthesis of mildly oxidized graphite and its formulation into screen‐printable inks. The screen‐printed electrodes exhibit sheet‐resistance below 1 Ω/sq after rolling‐compression, with a compressed film thickness of ≈3 μm and line‐width resolution below 100 μm. The method, described herein, can be used without the need for substrate‐limiting post‐printing treatments, such as high‐temperature annealing, photonic annealing, or chemical reduction. The approach is applicable to any arbitrary and heat‐sensitive substrate, including plastic and paper, and is both highly cost‐effective and suitable for roll‐to‐roll printing of a wide range of devices. High quality, mildly oxidized graphene‐based inks are screen‐printed on flexible substrates. The printed structures are highly conductive with a record sheet‐resistance of 1 Ω/sq after roll‐compression, and with no need for thermal or photonic annealing. This method paves the way for a scalable and cost‐efficient synthetic route to highly conductive printed graphene‐based electrode circuitries.