Subthreshold Characteristics of Printed Ion-Gated Crumpled Graphene Field Effect Transistors

High performance printable electronics are critical for advancing wearable and IoT systems. In this work, we demonstrate aerosol jet printed ion-gated field effect transistors (FETs) using crumpled graphene as the active channel material — a rarely explored material in previous studies. The unique wrinkled and folded structure of crumpled graphene increases interfacial interactions and electric double layer (EDL) effects. With this advantage, it can achieve a 42% lower subthreshold swing (SS) and a 19% higher on/off ratio compared to devices with a flat graphene channels. The improvements come from aerosol jet process based on formulated inks that leverage crumpled graphene's surface-area advantage for enhanced gate control. However, the porous morphology also introduces tradeoffs like hysteresis and carrier scattering, requiring careful design to balance morphology and performance. By connecting structure to function, crumpled graphene emerges as potential material for efficient printable electronics, with application in sensors and photodetectors.