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

The influence of gate voltage in the off state (V-g,V-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 V-g,V-off such as +0.5 V is used, a larger amount of Na+ ion injection is promoted as compared to lower V-g,V-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.

Automated summary

The study found that increasing the off state gate voltage increases the injection of Na+ ions, leading to drain current decay in OECT transfer characteristics; Crosslinking with PEDOT:PSS can significantly reduce the decay of drain current, improving the stability of OECT transfer characteristics; The decay of drain current is mainly attributed to the repetitive injection-extraction of cations under cycling gate bias.