Bias-stress induced instability of organic thin film transistors

We have investigated the stability of polythienylene vinylene field-effect transistors under gate bias stress. On time scales up to 1000 s and temperatures up to 140 °C, we only observe reversible charge relaxation effects and no degradation. We show the time dependence of the threshold voltage shift at different temperatures. Furthermore, we discuss the influence of water and oxygen on the relaxation process.