Frequency Characteristics of Ultrathin and Transparent Organic Electrochemical Transistors with 1-µm-Thick Parylene Lamination

Organic electrochemical transistors (OECTs) can be applied to biosensors because of their low operating voltages and mechanical flexibility. In this study, we developed a lamination process for transparent OECTs using 1-μm-thick Parylene films. The OECTs exhibit light transmissions exceeding 80%, operating voltages of 0.6 V, and frequency characteristics of approximately 50 Hz. Furthermore, the lamination process has the ability to change the size of the electrolyte window in which the electrolyte and semiconductor are in contact. The effects of the electrolyte window size on the frequency characteristics were evaluated. Further, information regarding the device shape that can improve the performance of the OECTs will be useful when they are integrated into transparent and flexible biosensors.