Understanding and Mitigating Charge-Trapping Induced Transfer Curve Drift in Electrolyte-Gated Graphene Field-Effect Transistors.

Electrolyte-gated graphene field-effect transistors (EG-gFETs) have great potential for chemical and biosensing applications and are increasingly attractive platforms for synaptic or memristive elements in neuromorphic computing. However, EG-gFETs exhibit drift in their electrical response, a phenomenon that remains poorly understood. An in-depth understanding of EG-gFETs' responses is essential for fully exploiting their behavior in applications and to open a much-needed discussion and standardization of practices within the community. In this work, we show that drift is ubiquitous across all tested devices and experimental conditions, and present evidence indicating that it is driven by progressive charge trapping in the insulating layer beneath the graphene channel. We then discuss potential strategies to mitigate drift, including alternative interrogation schemes and fabrication processes. Additionally, we propose approaches to enhance signal readability and facilitate discrimination of the signal from noise and false-positive responses in biosensing applications.