Polarization effects from the ambient and the gate dielectric on charge transport in polymer field-effect transistors

Abstract

Charge transport in polymer field-effect transistors is hugely affected by the polarization effects, which can be originated from polar molecules in the gate dielectric and ambient air. In this letter, we investigate the polarization induced trapping enhancement by dipoles in the gate dielectric layer and ambient air at the same time through the experiment with varying conditions of surface dielectric and polar analytes in the atmosphere. We demonstrate the result from diketopyrrolopyrrole based co-polymer transistors with high mobility. Polarization effects from dipoles in the atmosphere affect mostly the shallower trap states and are relatively less severe when the interface of the gate dielectric is very polar.