Direct-written polymer field-effect transistors operating at 20 MHz

Printed polymer electronics has long promised to revolutionize technology by enabling distributed, flexible, lightweight, and cost-effective applications for wearables and portable devices. However, despite advancements in organic semiconductor mobility, traditional field-effect transistors (FETs) still exhibit limited operational speeds, restricting their applicability, especially in driving high-resolution displays. Previous efforts to achieve tens of MHz operation in organic FETs have utilized complex lithographic techniques or architectures, which conflict with the objective of scalable production. In this study, we demonstrate polymer FETs capable of operating at 20 MHz, employing entirely scalable printed techniques without the use of masks. Our methodology integrates a femtosecond laser process to sinter high-resolution metal electrodes, producing micron-scale channels while reducing parasitic capacitance down to 0.19 pF mm-1. This approach combined with a large-area coating of a high mobility polymer semiconductor follows a straightforward and scalable fabrication process, advancing the potential for practical applications of polymer FETs in various electronic devices.