Crosslinked PEDOT:PSS Organic Electrochemical Transistors on Interdigitated Electrodes with Improved Stability

Abstract

The influence of gate voltage in the off state (Vg,off) on the stability of the transfer curve of an organic electrochemical transistor (OECT) based on interdigitated electrodes (IDEs) is studied in this work. When a high Vg,off such as +0.5 V is used, a larger amount of Na+ ion injection is promoted as compared to lower Vg,off, and a noticeable decay of drain current is observed in the transfer characteristics of the OECTs upon consecutive measurements. After the crosslinking of PEDOT:PSS, the decay of drain current can be significantly reduced, indicating the improved stability of transfer characteristics in the crosslinked OECTs. The mitigation effect after the crosslinking of PEDOT:PSS on the decay of drain current is also observed in the pulsed gate bias stress experiment, which allows the usage of a higher pulse gate voltage in the off state. The decay of drain current is likely attributed to the repetitive injection–extraction of cations (i.e., Na+) under cycling gate bias.