Short-time-scale threshold voltage shifts in organic field-effect transistors caused by dipoles on insulator surface

We previously reported that dipoles on the surface of the gate insulator layer in organic transistors cause time decay of the drain current on time scales of less than 0.1 s from the application of the gate voltage. In this study, we investigated the relationship between the time decay and magnitude of the gate voltage. We found that this time decay can be attributed to threshold voltage shifts unaccompanied by mobility changes. When the insulator surface has dipoles that can move somewhat, the threshold voltage shift has two components: one with a time scale of approximately 0.1 s and the other with a time scale of tens of minutes.