Stable operating windows for polythiophene organic electrochemical transistors

Organic electrochemical transistors (OECTs) have emerged as a promising platform for biosensing, electrophysiology, and neuromorphic devices. However, OECTs are often limited by the stability of the channel materials. Here, we systematically investigate the stability of OECT channels under varied operating voltage ranges. We find that OECT materials can be operated with high stability when the voltage range is reduced. We show that repeated full voltage cycling degrades device performance. The results indicate that to maximize stability, OECTs should either be operated in the saturation regime to maximize current gain (transconductance) or in the subthreshold regime to maximize the on/off ratio. Graphical abstract