Super-inkjet printing for three-terminal graphene field effect transistors with 10 μm channel length

Graphene field-effect transistors (GFETs) allow the determination of the electrical properties of this two-dimensional (2D) material and its interfaces to the environment. In this context, the electrode fabrication plays a crucial role. We explore inkjet-printed silver micro-electrodes as an efficient alternative to conventional fabrication techniques such as photolithography or sputtering. Inkjet printing significantly reduces the number of fabrication steps and enables arbitrary electrode placement on small samples. The fabricated GFETs were systematically measured under ambient conditions to extract carrier mobility and sheet resistance. Although individual measurements show variability, this uncertainty is reduced by analyzing multiple GFETs, enabling a more reliable assessment of graphene’s electrical properties. Furthermore, inkjet printing facilitates rapid prototyping and design modifications in laboratory settings. In this work, this flexibility allowed the integration of hexagonal boron nitride (h-BN) as an interfacial layer, providing a direct comparison between devices with and without h-BN. A notable finding is the fivefold pattern sharpening effect upon printing on graphene instead of the bare silicon dioxide insulator material.