Liquid-gate 2D material-on-insulator transistors for sensing applications

Abstract

This research investigates the use of 2D materials (specifically graphene) as active channel in liquid-gate transistors used as detectors of biological targets on functionalized surfaces. However, before these sensors can be effectively used, it is crucial to establish a reliable sensing platform within two-dimensional materials as active channels, and to evaluate the fabrication, lithography, and reliability of these devices. In this study, we analyzed the inter-device variability and reliability of the transistors, as well as the potential factors that may exacerbate these issues under operative conditions. We performed structural characterization to confirm the quality of the materials, followed by photolithography and processing to create liquid-gate sensors. We then conducted electrical evaluations of the devices, which revealed significant reliability issues and inter-device variability. To address these problems, we propose the use of an intergate-coupling effect that utilizes both front- and back-gates simultaneously. Our findings have important implications for the design and optimization of 2D materials-based liquid-gate sensors for biological applications.