Hysteresis mechanism and reduction method in the bottom-contact pentacene thin-film transistors with cross-linked poly(vinyl alcohol) gate insulator

Abstract

The origin of the hysteresis phenomenon in bottom-contact pentacene organic thin-film transistors (OTFTs) with cross-linked poly(vinyl alcohol) (PVA) insulator is studied. From electrical measurements with various sweep ranges and two different sweep directions, the hysteresis effect is presumed to be caused by the electrons or holes that could be injected from the gate and trapped in the PVA bulk, rather than by the polarization or internally existing mobile ions. The assumption is confirmed by the clear reduction of hysteresis in OTFTs with a blocking oxide layer between gate and PVA insulator.